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Introduction: The relationships between baseline tissue local impedance (LI), contact force (CF), atrial fibrosis, and atrial rhythm are uninvestigated in a clinical setting. We compared the relationship of LI and CF between atrial fibrillation (AF) and sinus rhythm (SR) accounting for the effects of atrial fibrosis as assessed by bipolar voltage and LI., Methods: Patients undergoing persistent AF ablation were recruited. LI was recorded referenced to patient blood pool (LIr) and concurrent to changes in CF, with data collected at the same locations in AF and SR., Results: Twenty patients were recruited. 109 locations were sampled obtaining 1903 data points (SR: 966, AF: 937). CF correlated strongly with LI (repeated measures correlation = 0.64). The relationship between CF and LIr was logarithmic. Rhythm and CF had a significant main (both p < .0005) and interaction effect (p = .022) on tissue LI: AF demonstrated higher LIr values than SR for similar CF. Bipolar voltage had no effect on the relationship of CF to LIr in either rhythm. Assessing fibrosis using LIr showed an interaction effect with CF for LIr in SR and AF, (SR: p < .0005, AF: p = .01), with increased fibrosis showing lesser change in LIr per gram of CF., Conclusions: CF and rhythm significantly affect the measured LIr of LA myocardium. Optimal catheter-tissue coupling may be better achieved with higher levels of CF and in AF rather than SR. Atrial fibrosis, as assessed by LIr but not bipolar voltage, affected the CF-LI relationship., (© 2024 The Authors. Journal of Cardiovascular Electrophysiology published by Wiley Periodicals LLC.)

Background: Percutaneous left atrial appendage occlusion (LAAO) has emerged as a non-pharmacologic alternative to oral anticoagulation in reducing stroke risk in AF patients. However, patients with mitral valve disease (MVD), who are expected to have a significantly greater risk of left atrium (LA) thrombus formation and embolic stroke were excluded from randomized trials examining percutaneous LAAO. To address this gap, we present a national registry analysis of the use of LAAO among patients with MVD., Methods: Using the National Readmissions Database, we performed a retrospective review of all hospitalizations for LAAO identified between September 2015 and November 2019. Of these, patients with ICD-10 codes for MVD were identified. Propensity matched (PSM) analysis was used to compare patients with MVD with a matched sample of patients undergoing LAAO with non-valvular AF. Outcomes examined included all-cause mortality, stroke, major bleeding, pericardial effusion (PE), and tamponade., Results: 51,540 patients who underwent LAAO without a history of MVD and 3777 with a history of MVD were identified. Crude analysis demonstrated the odds of mortality, PE, and cardiac tamponade during index hospitalization to be higher in the MVD group. The length of stay and cost of index hospitalization were also slightly greater for the MVD group. A sample of 7649 patients (MVD: 3777 MVD and no MVD: 3872) were selected for PSM analysis with similar comorbidities across the two groups. In the PSM comparison, MVD was associated with higher risk of PE. The MVD group had a slightly higher rate of readmissions the association with PE remained at 30-day readmission (OR: 2.099 [1.360-3.238], p-value: <0.001)., Conclusion: To our knowledge, this is the first study examining the use of LAAO among MVD patients. Our findings suggest that patients with MVD who underwent LAAO had a higher risk of post-procedural PE without an increase in mortality, stroke, or major bleeding. These results provide a rationale for considering LAAO as part of the stroke prevention strategy among patients with valvular AF., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Steven Filby reports a relationship with Boston Scientific Corp that includes: consulting or advisory. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: Ultra high-density mapping systems allow for comparison of atrial electroanatomical maps in unprecedented detail. Atrial scar determined by voltages and surface area between atria, rhythm and atrial fibrillation (AF) types was assessed., Methods: Left (LA) and right atrial (RA) maps were created using Rhythmia HDx in patients listed for ablation for paroxysmal (PAF, sinus rhythm (SR) maps only) or persistent AF (PeAF, AF and SR maps). Electrograms on corresponding SR/AF maps were paired for direct comparison. Percentage surface area of scar was assigned low- (LVM, ≤ 0.05 mV), intermediate- (IVM, 0.05-0.5 mV) or normal voltage myocardium, (NVM, > 0.5 mV)., Results: Thirty-eight patients were recruited generating 96 maps using 913,480 electrograms. Paired SR-AF bipolar electrograms showed fair correlation in LA (Spearman's ρ = 0.32) and weak correlation in RA (ρ = 0.19) and were significantly higher in SR in both (LA: 0.61 mV (0.20-1.67) vs 0.31 mV (0.10-0.74), RA: 0.68 mV (0.19-1.88) vs 0.47 mV (0.14-1.07), p < 0.0005 both). Voltages were significantly higher in patients with PAF over PeAF, (LA: 1.13 mV (0.39-2.93) vs 0.52 mV (0.16-1.49); RA: 0.93 mV (0.24-2.46) vs 0.57 mV (0.17-1.69)). Minimal differences were seen in electrogram voltages between atria. Significantly more IVM/LVM surface areas were seen in AF over SR (LA only, p < 0005), and PeAF over PAF (LA: p = 0.01, RA: p = 0.04). There was minimal difference between atria within patients., Conclusions: Ultra high-density mapping shows paired electrograms correlate poorly between SR and AF. SR electrograms are typically (but not always) larger than those in AF. Patients with PeAF have a lower global electrogram voltage than those with PAF. Electrogram voltages are similar between atria within individual patients., (© 2023. The Author(s).)

Evidence on the relative safety and efficacy of atrial fibrillation catheter ablation and antiarrhythmic drugs (AADs) as the first-line therapy for patients with treatment-naive atrial fibrillation (AF) remains disputed. Digital databases were queried to identify relevant randomized controlled trials. The incidence of recurrent AF, major adverse cardiovascular events, and its components (all-cause death, nonfatal stroke, and bleeding) were compared using the DerSimonian and Laird method under the random-effects model to calculate pooled unadjusted risk ratio (RR) with 95% confidence intervals (CIs). A total of 6 randomized controlled trials consisting of 1,120 patients (574 ablation and 549 AADs) were included in the final analysis. Over a median follow-up of 1 year, the risk of any AF recurrence (RR 0.54, 95% CI 0.39 to 0.75) was significantly lower in patients receiving ablation than in patients receiving AADs. However, there was similar risk of major adverse cardiovascular events (RR 2.65, 95% CI 0.61 to 11.46), trial-defined composite end point of adverse events (RR 0.71, 95% CI 0.28 to 1.80), stroke (RR 2.42, 95% CI 0.22 to 26.51), all-cause mortality (RR 1.98, 95% CI 0.28 to 13.90), and procedure/medication failure (RR 2.65, 95% CI 0.61 to 11.46) with both therapies. In conclusion, in patients presenting with treatment-naive AF, ablation as a first-line therapy lowers the risk of AF recurrence with no associated increase in major adverse events, stroke, and mortality compared with AADs., Competing Interests: Declaration of competing interest The authors have no competing interest to declare., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Transcatheter aortic valve replacement (TAVR) is the treatment of choice for patients with severe aortic stenosis across the spectrum of surgical risk. About one-third of 30-day readmissions following TAVR are related to heart failure (HF). Hence, we aim to develop an easy-to-use clinical predictive model to identify patients at risk for HF readmission. We used data from the National Readmission Database (2015-2018) utilizing ICD-10 codes to identify TAVR procedures. Readmission was defined as the first unplanned HF readmission within 30-day of discharge. A machine learning framework was used to develop a 30-day TAVR-HF readmission score. The receiver operator characteristic curve was used to evaluate the predictive power of the model. A total of 92,363 cases of TAVR were included in the analysis. Of the included patients, 3299 (3.6%) were readmitted within 30 days of discharge with HF. Individuals who got readmitted, vs those without readmission, had more emergent admissions during index procedure (33.4% vs 19.8%), electrolyte abnormalities (38% vs 16.7%), chronic kidney disease (34.8% vs 21.2%), and atrial fibrillation (60.1% vs 40.7%). Candidate variables were ranked by importance using a parsimony plot. A total of 7 variables were selected based on predictive ability as well as clinical relevance: HF with reduced ejection fraction (25 points), HF preserved EF (20 points), electrolyte abnormalities (17 points), atrial fibrillation (12 points), Charlson comorbidity index (<6 = 0, 6-8 = 9, 9-10 = 13, >10 = 14 points), chronic kidney disease (7 points), and emergent index admission (5 points). On performance evaluation using the testing dataset, an area under the curve of 0.761 (95% CI 0.744-0.778) was achieved. Thirty-day TAVR-HF readmission score is an easy-to-use risk prediction tool. The score can be incorporated into electronic health record systems to identify at-risk individuals for readmissions with HF following TAVR. However, further external validation studies are needed., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier Inc.)

Background: The optimal power and duration settings for radiofrequency (RF) atrial fibrillation (AF) ablation to improve efficacy and safety is unclear. We compared low-power long-duration (LPLD), high-power short-duration (HPSD), and very HPSD (vHPSD) RF settings for AF ablation., Methods: This network meta-analysis (NMA) was structured according to the Preferred Reporting Items for Systematic Review and Meta-Analyses guidelines. Medline, Scopus and Cochrane Central Register of Controlled Trials were systematically searched to identify relevant studies. Observational and randomized studies were included. Eligible studies compared outcomes in AF patients who underwent first-time RF ablation with the following settings: vHPSD (70-90 W, 3-10 s), HPSD (45-60 W, 5-10 s), or LPLD (20-40 W, 20-60 s)., Results: Thirty-six studies comprising 10,375 patients were included (33% female). Frequentist NMA showed LPLD tended toward a lower odds of freedom from arrhythmia (FFA) versus HPSD (OR 0.93, 95% CI 0.86-1.00). There was no difference in FFA between vHPSD versus HPSD. Splitwise interval estimates showed a lower odds of FFA in LPLD versus vHPSD on direct (OR 0.78, 95% CI 0.65-0.93) and network estimates (OR 0.85, 95% CI 0.73-0.98). Frequentist NMA showed less total procedural (TP) time with HPSD versus LPLD (generic variance 1.06, 95% CI 0.83 to 1.29) and no difference between HPSD versus vHPSD., Conclusion: This NMA shows improved procedural times in HPSD and vHPSD versus LPLD. Although HPSD tended toward improved odds of FFA compared to LPLD, the overall result was not statistically significant. The odds of FFA in LPLD was lower versus vHPSD on direct and network estimates on splitwise interval analysis. Large prospective head-to-head randomized trials are needed to validate HPSD and vHPSD settings., (© 2023 Wiley Periodicals LLC.)

Background: Atrial fibrillation (AF) is common in patients with hypertrophic cardiomyopathy (HCM) and can be challenging to manage. Atrioventricular nodal (AVN) ablation may be an effective management strategy for AF in these patients., Objective: The purpose of this study was to assess the efficacy of AVN ablation in HCM patients who have failed medical therapy and/or catheter ablation for AF., Methods: A multicenter study with retrospective analysis of a prospectively collated HCM registry was performed. AVN ablation patients were identified. Baseline characteristics and device and procedural indications were collected. Symptoms defined by New York Heart Association and European Heart Rhythm Association classification and echocardiographic findings during follow-up were assessed., Results: Fifty-nine patients were included in the study. Indications for AVN ablation were 6 (10.2%) inappropriate implantable cardioverter-defibrillator shock, 35 (59.3%) ineffective rate control, and 18 (30.5%) to regularize rhythm for symptom improvement. During post-AVN ablation follow-up of 79.4 ± 61.1 months, left ventricular ejection fraction (LVEF) remained stable (pre-LVEF 48.9% ± 12.6% vs post-LVEF 50.1% ± 10.1%; P = .29), even in those without a cardiac resynchronization therapy (CRT) device (pre-LVEF 54.3% ± 8.0% vs post-LVEF 53.8% ± 8.0%; P = .65). Forty-nine patients (83.1%) reported an improvement in symptoms regardless of AF type (17/21 [81.0%] paroxysmal vs 32/38 [84.2%] persistent; P = 1.00), presence of baseline left ventricular impairment (22/26 [84.6%] LVEF ≤50% vs 27/33 [81.8%] LVEF ≥50%; P = 1.00) or CRT device (27/32 [84.4%] CRT vs 22/27 [81.5%] no CRT; P = 1.00). Symptoms improved in 16 patients (89.0%) who underwent AVN ablation to regularize rhythm., Conclusion: AVN ablation improved symptoms without impacting left ventricular function in the majority of patients. The data suggest that AVN ablation is an effective and safe management approach for AF in HCM and should be further evaluated in larger prospective studies., (Copyright © 2023 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Data on the feasibility of same-day discharge (SDD) following percutaneous left atrial appendage closure (LAAC) remain limited. We analyzed the US Nationwide Readmission Database from quarter four of 2015 to 2019 to study the safety and feasibility of SDD after LAAC. After excluding non-elective cases and in-hospital deaths, a total of 54,880 cases of LAAC were performed during the study period. Following LAAC, 2% (n=1077) of patients underwent SDD, 88% (n=48,428) underwent next-day discharge (NDD), 5.2% (n=2881) were discharged on the second day (ScD), and 4.5% of patients (n = 2494) were discharged 3 or more days after LAAC. There was no difference in 30-day readmission rates between SDD and NDD (7.3% [n=79] vs 7.4% [n=3585], P=0.94). The hospitalization costs were significantly lower for SDD compared with NDD ($22,963 vs $27,079, P≤0.01). SDD discharge following percutaneous LAAC appears to be safe and is associated with lower hospitalization costs. Further prospective studies are needed to determine the safety and feasibility of SDD with percutaneous LAAC., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Left atrial appendage occlusion using the Watchman device has emerged as an alternative treatment strategy for preventing strokes in patients with atrial fibrillation. However, there is no data on its safety and clinical outcomes in prior renal or liver transplant recipients. We included a total of 61,995 patients from the National Inpatient Sample (NIS, in-hospital outcomes) and 55,048 patients from the National Readmission Database (NRD, 30-day outcomes) who underwent percutaneous left atrial appendage occlusion (LAAO). From this group, 0.65% (n=405) and 0.62% (n=339) were renal and liver transplant recipients in NIS and NRD respectively. Transplant recipients were younger compared with non-transplant recipients (mean age 69 vs 77 years, P=<0.01). There was little difference in terms of in-hospital mortality (0% vs 0.2%, P=0.43), major complications (6.2% vs 5.6%, P=0.61), cardiovascular complications (2.5% vs 2.8%, P=0.73), neurological complications (1.2% vs 0.7%, P=0.21) or bleeding complications (1.2% vs 0.7%, P=0.99) between transplant vs. non-transplant patients. Based on the NRD database, 30-day readmission rate was not meaningfully different for transplant recipients undergoing LAAO (9.44%) when compared to non-transplant patients (8.12%, [log-rank, P=0.56]). There was no difference between 30-day major or cardiovascular complications, however vascular complication rates were significantly higher for transplant recipients (OR 2.56, 95% CI [(1.66-3.47]). Our study findings suggest that LAAO may be safe for patients with a prior renal or liver transplant in terms of major complications, cardiovascular complications, and all-cause readmission rates. However vascular complications may be higher in transplant recipients. Further large-scale studies are needed to confirm these findings., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Transcutaneous aortic valve implantation (TAVI) has transformed the management of aortic stenosis (AS) and is increasingly being used for patients with symptomatic, severe aortic stenosis who are ineligible or at high risk for conventional cardiac surgery. PUBMED, Google Scholar, and SCOPUS databases were searched to identify studies reporting heart failure hospitalization after TAVI. Major factors evaluated for HF hospitalization were age, comorbidities such as hypertension, atrial fibrillation (AF), chronic pulmonary disease including COPD, chronic kidney disease, baseline LVEF before the procedure, NYHA symptom class, and society of thoracic surgeons (STS) score. Hazard ratio (HR) with a 95% confidence interval were computed using random-effects models. A total of eight studies were included comprising 77,745 patients who underwent TAVI for severe aortic stenosis. The presence of diabetes mellitus (HR: 1.39, 95% CI [1.17, 1.66], chronic kidney disease (CKD) (HR: 1.39, 95% CI [1.31, 1.48], atrial fibrillation (HR: 1.69, 95% CI [1.42, 2.01], chronic pulmonary disease (HR: 1.33, 95% CI [1.12, 1.58], and a high STS score (HR: 1.07, 95% CI [1.03, 1.11] were positive predictors of 1-year HF hospitalization after TAVI. Patients with diabetes mellitus, AF, CKD, chronic pulmonary disease, and a high STS score are at an increased risk of heart failure hospitalization at 1-year of TAVI, whereas increasing age, hypertension, LVEF <50%, and NYHA class III/IV symptoms did not predict HF hospitalization. Careful follow-up after TAVI in high-risk patients, with closer surveillance for HF particularly, is key to preventing HF hospitalizations and death., (Copyright © 2022. Published by Elsevier Inc.)

Background We describe sex-differential disease patterns and outcomes of >20.6 million cardiovascular emergency department encounters in the United States. Methods and Results We analyzed primary cardiovascular encounters from the Nationwide Emergency Department Sample between 2016 and 2018. We grouped cardiovascular diagnoses into 15 disease categories. The sample included 48.7% women; median age was 67 (interquartile range, 54-78) years. Men had greater overall baseline comorbidity burden; however, women had higher rates of obesity, hypertension, and cerebrovascular disease. For women, the most common emergency department encounters were essential hypertension (16.0%), hypertensive heart or kidney disease (14.1%), and atrial fibrillation/flutter (10.2%). For men, the most common encounters were hypertensive heart or kidney disease (14.7%), essential hypertension (10.8%), and acute myocardial infarction (10.7%). Women were more likely to present with essential hypertension, hypertensive crisis, atrial fibrillation/flutter, supraventricular tachycardia, pulmonary embolism, or ischemic stroke. Men were more likely to present with acute myocardial infarction or cardiac arrest. In logistic regression models adjusted for baseline covariates, compared with men, women with intracranial hemorrhage had higher risk of hospitalization and death. Women presenting with pulmonary embolism or deep vein thrombosis were less likely to be hospitalized. Women with aortic aneurysm/dissection had higher odds of hospitalization and death. Men were more likely to die following presentations with hypertensive heart or kidney disease, atrial fibrillation/flutter, acute myocardial infarction, or cardiac arrest. Conclusions In this large nationally representative sample of cardiovascular emergency department presentations, we demonstrate significant sex differences in disease distribution, hospitalization, and death.

Contemporary data on stroke predictors and outcomes in patients undergoing transcatheter aortic valve implantation (TAVI) remains limited. We analyzed National Inpatient Sample data from the year 2011 to 2018. A total of 215,938 patients underwent TAVI. Of the patients who underwent TAVI, 4579 (2.2%) suffered from stroke and 211359 (97.8%) did not have a stroke. Adjusted mortality was higher in patients who had a stroke (10.9%) as compared to patients who did not have a stroke (3.1%). Lower percentage of patients were discharged home who developed a stroke compared to patients without a stroke (10.2% vs 52.3%). Multivariate logistic regression analysis showed that at baseline, age, female sex, atrial fibrillation, chronic kidney disease and peripheral vascular disease were significant predictors of stroke. Median Cost of care ($63367 vs $48070) and length of stay (8 vs 4 days) were considerably higher for patients with stroke when compared to the comparison group (P < 0.01 for all). In conclusion we report that stroke is associated with increased mortality, morbidity, and resource utilization in patients undergoing TAVI. Baseline characteristics like age, gender, atrial fibrillation, chronic kidney disease and peripheral vascular disease are significant predictors of this adverse event., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Atrial fibrillation (AF) is the most prevalent arrhythmia in the United States. However, studies evaluating the impact of iron deficiency anemia on AF outcomes are limited. Therefore, we aimed to evaluate the association of iron deficiency anemia (IDA) on clinical outcomes in patients hospitalized with AF. A retrospective analysis of adult hospital discharges from the National Inpatient Sample (NIS) between 2004 and 2018 was conducted. Multivariable logistic regression was used to assess the association of IDA and other clinical outcomes ie inpatient mortality, acute myocardial infarction, cardiogenic shock, acute kidney injury, vasopressors use, length of stay, and other resource utilization. These models were adjusted for patient and hospital-level characteristics. A total of 5,975,241 weighted primary AF hospitalizations were identified. Out of these, 152,059 (2.5%) had diagnosis of IDA. After adjustment of variables, admissions with IDA were associated with higher rates of acute myocardial infarction (adjusted odds ratio [aOR] = 1.10, 95% CI 1.01-1.19 P = 0.026), use of vasopressors (aOR = 1.30, CI 1.27-1.32, P <0.001), invasive mechanical ventilation (aOR = 1.26, CI 1.14-1.40 P <0.001) and acute kidney injury (aOR = 1.72, CI 1.66-1.79 P <0.001). There was no significant difference in all-cause mortality (aOR = 0.97, CI 0.87-1.07, P = 0.513), cardiogenic shock, in-hospital cardiac arrest or use of mechanical circulatory support. Adjusted mortality in patients with AF and IDA decreased from 1.09% to 0.54% from 2004 to2018 (P -trend < 0.001). Among hospitalized patients with AF, our study did not show any difference in all-cause mortality between those with and without IDA., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Background: The relative accuracy of pulsatile photoplethysmography applications (PPG) or handheld (HH) devices compared with the gold standard 12-lead electrocardiogram (ECG) for the diagnosis of atrial fibrillation is unknown., Methods: Digital databases were searched to identify relevant articles. Raw data were pooled using a bivariate model to calculate diagnostic accuracy measures and estimate Hierarchical Summary Receiver Operating Characteristic (HSROC)., Results: A total of 10 articles comprising 4296 patients (mean age 68.9 years, with 56% males) were included in the analysis. Compared with EKG, the pooled sensitivity of PPG and HH devices in AF detection was 0.93 (95% CI 0.87-0.96; p < 0.05) and 0.87 (95% CI. 0.74-0.94; p < 0.05), respectively. The pooled specificity of PPG and HH devices in AF detection was 0.91 (95% CI 0.88-0.94; p < 0.05) and 0.96 (95% CI 0.90-0.98; p < 0.05), respectively. The diagnostic odds ratio was 129 and 144 for PPG and HH devices, respectively. Fagan's nomogram showed the probability of a patient having AF and normal rhythm on PPG or HH devices was 2-3%, while the post-test probability of having AF with an irregular R-R interval on PPG or HH devices was 73% and 82%, respectively. The scatter plot of positive and negative likelihood ratio showed high confirmation of AF and reliability of exclusion of absence of irregular R-R intervals (positive likelihood ratio > 10, and negative likelihood ratio < 0.1) on HH devices while PPG was used as confirmation only., Conclusions: The PPG or HH devices can serve as a reliable alternative for the detection of AF., (© 2021. Springer Science+Business Media, LLC, part of Springer Nature.)

New-onset post-cardiac surgery atrial fibrillation (PCSAF) is a frequent complication with estimated incidence of 17% to 64%, depending on type of surgery. It is associated with higher mortality, morbidity, and predisposition to stroke and systemic embolism postoperatively. Standard care involves rate or rhythm control, in addition to antithrombotic therapy in those with history of stroke, transient ischemic attack, or high risk of systemic thromboembolism. However, risk of bleeding is not negligible, and treating physicians should weigh the risks and benefits before committing to postoperative anticoagulation therapy. More investigations are warranted to explore antithrombotic therapy benefit, particularly postoperative anticoagulation, considering the potentially self-limited nature of the arrhythmia and high risk of postoperative bleeding., (Copyright © 2022 The Cleveland Clinic Foundation. All Rights Reserved.)

Major bleeding has been identified as one of the most common complications after transcatheter aortic valve implantation (TAVI) with some suffering gastrointestinal bleeding (GIB). This study aimed at assessing the incidence and predictors of GIB after TAVI in the United States. We performed a retrospective analysis of data from the National Inpatient Sample database from 2011 to 2018. A total of 216,023 hospitalizations for TAVI were included. Of the included patients, 2,188 (1%) patients had GIB, whereas 213,835 (99%) patients did not have GIB. The presence of arteriovenous malformation was associated with the highest odds of having a gastrointestinal bleed (odds ratio (OR) 24.8, 95% confidence interval (CI) 17.13 to 35.92). Peptic ulcer disease was associated with an eightfold increased risk of bleeding (OR 8.74, 95% CI, 6.69 to 11.43) followed closely by colorectal cancer (OR 7.89, 95% CI, 5.33 to 11.70). Other comorbidities that were associated with higher propensity-matched rates of GIB were chronic kidney disease (OR 1.27,95% CI, 1.14 to 1.41), congestive heart failure (OR 1.18, 95% CI,1.06 to 1.32), liver disease (OR1.83, 95% CI,1.53 to 2.19), end-stage renal disease (OR 2.08,95% CI, 1.75 to 2.47), atrial fibrillation (OR1.63,95% CI,  1.49 to 1.78), and lung cancer (OR 2.80, 95% CI,1.77 to 4.41). Patients with GIB had higher propensity-matched rates of mortality than those without GIB, (12.1% vs 3.2%, p <0.01). Patients with GIB had a higher median cost of stay ($68,779 vs $46,995, p <0.01) and a longer length of hospital stay (11 vs 3 days, p <0.01). In conclusion, health care use and mortality are higher in hospitalizations of TAVI with a GIB. Baseline comorbidities like peptic ulcer disease, chronic kidney disease, liver disease, atrial fibrillation and, colorectal cancer are significant predictors of this adverse event., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Objectives: This analysis was performed to evaluate the transition of local impedance (LI) drop during pulmonary vein isolation (PVI) to durable block and mature lesion formation based on 3-month mapping procedures., Background: A radiofrequency catheter measuring LI has been shown to be effective for performing PVI in patients with paroxysmal atrial fibrillation. Previous analysis has demonstrated LI drop to be predictive of pulmonary vein segment conduction block during an atrial fibrillation ablation procedure., Methods: Fifty-eight patients who had undergone LI-blinded de novo PVI returned for a 3-month mapping procedure. PVI ablation circles were divided into 16 anatomic segments for classification (durable block or gap), and the median LI drop within segments with an interlesion distance of ≤6 mm was compared. A total of 51 data sets met the criteria for segmental analysis of LI performance., Results: At the 3-month procedure, PV connection was confirmed in at least 1 PV segment in 35 of the included patients. LI drop outperformed generator impedance drop as a predictor of durable conduction block (area under the receiver-operating characteristic curve: 0.79 vs 0.68; P = 0.003). Optimal LI drops were identified by left atrial region (anterior/superior: 16.9 Ω [sensitivity: 69.1%; specificity: 85.0%; positive predictive value for durable conduction block: 97.7%]; posterior/inferior:14.2 Ω [sensitivity: 73.8%; specificity: 78.3%; positive predictive value: 96.9%]). Starting LI before radiofrequency (RF) application was significantly different among healthy, gap, and mature scar tissue and was also a contributing factor to achieving an optimal LI drop (85.2% of RF applications with a starting LI of ≥110 Ω achieved the optimal regional drop or greater)., Conclusions: LI drop is predictive of durable PV segment isolation. Preablation starting LI is associated with the magnitude of LI drop. These findings suggest that a regional approach to RF ablation guided by LI combined with careful interlesion distance control may be beneficial in patients with paroxysmal atrial fibrillation (Electrical Coupling Information From the Rhythmia HDx System and DirectSense Technology in Subjects With Paroxysmal Atrial Fibrillation [LOCALIZE]; NCT03232645)., Competing Interests: Funding Support and Author Disclosures This study was funded by Boston Scientific. Dr García-Bolao has received research funding and speaker/proctorship fees from Boston Scientific and consultancy fees from Abbott and Biosense Webster. Dr Luik is a consultant for Biosense Webster and Boston Scientific; and has received speaker fees from Bristol Myers Squibb. Dr Sulkin was a salaried employee of Boston Scientific at the time of the study. Dr Gutbrod is a salaried employee of Boston Scientific. Dr Oesterlein is a salaried employee of Boston Scientific. Dr Richards is a salaried employee of Boston Scientific. Dr Laughner was a salaried employee of Boston Scientific at the time of the study. Dr Meyer has received consultant fees from Biosense Webster and Boston Scientific; and has received speaker fees from Abbott, Biosense Webster, and Boston Scientific. Dr Yue has received speaker fees from Boston Scientific. Dr Ullah has received research funding from Boston Scientific and Biosense Webster. Dr Shepherd has received speaker fees from Boston Scientific and ACUTUS Medical. Dr Das has received research funding and speaker/proctorship fees from Boston Scientific. Dr Ramos has reported that he has no relationships relevant to the contents of this paper to disclose., (Copyright © 2022 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: Inaccurate sizing of left atrial appendage (LAA) occlusion devices is associated with increased stroke risk. We compared the LAA size to implant the Watchman device assessed by computed tomography (CT) to transesophageal echocardiography (TEE)., Methods: Databases were searched to identify studies comparing LAA anatomical measurements and procedural outcomes across imaging modalities for the Watchman device implantation., Results: Seven studies were included in the analysis (242 patients on TEE, and 232 on CT). The LAA orifice was larger when sized with CT compared to TEE (CT mean vs TEE SMD 0.30 mm, 95%CI 0.09-0.51 mm, P < 0.01; and CT max vs TEE SMD 0.69 mm, 95%CI 0.51-0.87 mm, P < 0.001). Additionally, CT, including CT-based 3-dimensional models, had higher odds of predicting correct device size compared to TEE (OR 1.64; 95%CI 1.05-2.56; P = 0.03). CT resulted in a lower fluoroscopy time vs TEE (SMD -0.78 min, 95% CI -1.39 to -0.18, P = 0.012). No significant differences were found in device clinical outcomes., Conclusion: Compared to TEE, CT resulted in larger LAA orifice measurements, improved odds of predicting correct device size, and reduced fluoroscopy time in patients undergoing LAA occlusion with the Watchman device. There were no significant differences in other procedural outcomes.

Background: Atrial fibrillation (AF) is one of the most frequent rhythm disturbance encountered in the population in general. Our study aims to evaluate the in-hospital outcomes of TAVR with AF., Methods: We used National Inpatient Sample database from 2011 to 2018. Baseline characteristics and in-hospital outcomes were evaluated in TAVR based on AF status or not in both unmatched and propensity-matched cohorts., Results: A total of 215,938 patients underwent TAVR during our study period and out of these AF was encountered in 89,587 (41.5%) patients. AF patients undergoing TAVR had a higher mean age and had an increased burden of key co-morbidities in the unmatched cohort. With propensity matched 1:1 analysis, AF had higher mortality as compared to no-AF group (2.4% vs. 2.1%, p < 0.01). The rate of cardiogenic shock (2.9% vs 2.1%), respiratory complications (9.9% vs 8.2%), acute kidney injury (15.6% vs 12.0%), vascular complications (5.0% vs 4.7%), and blood transfusion (10.4% vs 8.6%) was higher in TAVR patients with AF. A lower proportion of patients had routine discharge to home for TAVR with AF (80.8% vs 74.4%). Cost of hospitalization (23,0171[SD, 20,5242] vs 210,608[28,4203]) and length of stay (5.7[SD, 11.8] vs 4.29[7.2] days) were considerably higher in patients undergoing TAVR with AF., Conclusion: Patients undergoing TAVR with concomitant AF tended to have increased mortality, complications, length, and cost of stay compared to non-AF patients.

Background: The use of warfarin in patients with atrial fibrillation (AF) and end-stage renal disease (ESRD) has been implicated with efficacy and safety concerns. Evidence on the role of direct oral anticoagulants (DOACs) in this population is limited., Methods: Electronic databases were searched and articles comparing the safety and efficacy of warfarin with apixaban or rivaroxaban were identified. Pooled hazard ratios (HR) were computed using a random-effects model., Results: A total of eight articles consisting of 30,806 patients; (rivaroxaban 2196, apixaban 2745 and warfarin 25,865) were identified. The pooled HR for major bleeding events favored apixaban over warfarin (0.53, 95% confidence interval (CI) 0.33-0.84, p = 0.008). Apixaban was similar to warfarin in terms of clinically relevant non-major bleeding (HR 1.08, 95% CI 0.64-1.84, p = 0.77) and stroke events (HR 1.09, 95% CI 0.85, 1.39, p = 0.99). There was no significant difference in the risk of major bleeding events (HR 0.95, 95% CI 0.50-1.81, p = 0.88) and stroke between rivaroxaban (HR 1.39, 95% CI, 0.59-3.29, p = 0.09) and warfarin. The combined results of major bleeding in the apixaban group were not affected by the sensitivity analysis., Conclusions: Apixaban may have a lower risk of major bleeding and comparable risk of stroke when compared with warfarin in AF patients with ESRD., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Aims: Radiofrequency ablation creates irreversible cardiac damage through resistive heating and this temperature change results in a generator impedance drop. Evaluation of a novel local impedance (LI) technology measured exclusively at the tip of the ablation catheter found that larger LI drops were indicative of more effective lesion formation. We aimed to evaluate whether LI drop is associated with conduction block in patients with paroxysmal atrial fibrillation (AF) undergoing pulmonary vein isolation (PVI)., Methods and Results: Sixty patients underwent LI-blinded de novo PVI using a point-by-point ablation workflow. Pulmonary vein rings were divided into 16 anatomical segments. After a 20-min waiting period, gaps were identified on electroanatomic maps. Median LI drop within segments with inter-lesion distance ≤6 mm was calculated offline. The diagnostic accuracy of LI drop for predicting segment block was assessed using receiver operating characteristic analysis. For segments with inter-lesion distance ≤6 mm, acutely blocked segments had a significantly larger LI drop [19.8 (14.1-27.1) Ω] compared with segments with gaps [10.6 (7.8-14.7) Ω, P < 0.001). In view of left atrial wall thickness differences, the association between LI drop and block was further evaluated for anterior/roof and posterior/inferior segments. The optimal LI cut-off value for anterior/roof segments was 16.1 Ω (positive predictive value for block: 96.3%) and for posterior/inferior segments was 12.3 Ω (positive predictive value for block: 98.1%) where inter-lesion distances were ≤6 mm., Conclusion: The magnitude of LI drop was predictive of acute PVI segment conduction block in patients with paroxysmal AF. The thinner posterior wall required smaller LI drops for block compared with the thicker anterior wall., (© The Author(s) 2021. Published by Oxford University Press on behalf of the European Society of Cardiology.)

Background: Adjunctive use of oral anticoagulant (OAC) and antiplatelet therapy (APT) in patients with stable coronary artery disease (CAD) and nonvalvular atrial fibrillation (AF) is a challenge of daily practice., Methods: A comprehensive literature search of databases was performed to identify studies comparing the safety and efficacy of OAC monotherapy and combined therapy (OAC plus single (S) APT). Events including major adverse cardiovascular events (MACE), all-cause mortality, stroke and major bleeding were analyzed., Results: Seven articles comprising 11,070 subjects were identified. Combined therapy was associated with a significantly higher risk of major bleeding (pooled hazard ratio (HR) of 1.62, 95% CI 1.40-1.86, p=<0.0001) compared to the OAC monotherapy. There was no significant difference between the two comparison arms in terms of MACE (HR 1.14; 95% CI 0.97-1.34, p = 0.11), stroke (HR 1.05; 95% CI 0.77-1.43, p = 0.78) and all-cause mortality (HR 1.15; 95% CI 0.94-1.40, p = 0.16). Stratified analysis by inclusion of only patients with coronary stents attenuated the safety effect of monotherapy. Subgroup analysis based on the study design, type of OAC, major bleeding criteria and APT revealed findings consistent with the pooled HR. The combined therapy group had a 19% and 38% higher risk of MACE in studies with a history of MI (p = 0.03) and with the use of rivaroxaban (p = 0.02), respectively., Conclusion: OAC monotherapy might have a lower incidence of major bleeding events with no higher overall risk of MACE, ischemic stroke and all-cause mortality compared to the combined therapy group., (Copyright © 2020 European Federation of Internal Medicine. Published by Elsevier B.V. All rights reserved.)

Introduction: The optimal way to map localized drivers in persistent atrial fibrillation (AF) remains unclear. The objective of the study was to apply a novel vector mapping approach called Stochastic Trajectory Analysis of Ranked signals (STAR) in AF., Methods and Results: Patients having persistent AF ablation were included. Early sites of activation (ESA) identified on global STAR maps created with basket catheters were used to guide AF ablation post-pulmonary vein isolation (PVI). All patients also had sequential STAR maps created with ≥10 PentaRay recordings of 30 seconds. These were validated offline in their ability to identify the ESA targeted with a study-defined ablation response (AF termination or cycle length [CL] slowing of ≥30 ms). Thirty-two patients were included in whom 92 ESA were identified on the global STAR maps, with 73 of 83 targeted sites demonstrating an ablation response (24 AF termination and 49 CL slowing). Sixty-one out of 73 (83.6%) ESA were also identified on the sequential STAR maps. These showed greater consistency (P < .001), were seen pre- and post-PVI (P < .001) and were more likely to be associated with AF termination on ablation (P = .007). The sensitivity and specificity of sequential mapping for the detection of ESA with an ablation response was 84.9% (95% confidence interval [CI] = 74.6-92.2) and 90.0% (95% CI = 55.5-99.8), respectively. During a follow-up of 19.4 ± 3.7 months, 28 (80%) patients were free from AF/atrial tachycardia., Conclusions: STAR mapping consistently identified ESA in all patients and the ablation response was compatible with ESA being driver sites. Mechanistically important ESA were successfully identified using sequential recordings., (© 2019 The Authors. Journal of Cardiovascular Electrophysiology published by Wiley Periodicals, Inc.)

Objectives: The aim of this study was to demonstrate that a stochastic vector-based mapping approach could guide ablation of atrial fibrillation (AF) drivers as evidenced by ablation response and long-term follow-up outcomes., Background: The optimal method for mapping and ablation of AF drivers is yet to be defined., Methods: Patients undergoing persistent AF ablation were recruited. Patients underwent pulmonary vein isolation (PVI) with further ablation guided by the stochastic trajectory analysis of ranked signals (STAR) mapping method. The proportion of the time an electrode's activation was seen to precede its neighboring electrodes activation was used to determine early sites of activation (ESA). A positive ablation response at ESA was defined as AF termination or cycle length slowing of ≥30 ms. Clinical outcome was defined as recurrence of AF/atrial tachycardia (AT) during a follow-up of 12 months., Results: Thirty-five patients were included (AF duration of 14.4 ± 5.3 months). After PVI, an average of 2.6 ± 0.8 ESA were ablated per patient with study-defined ablation response achieved in all patients. Of the 86 STAR maps created post-PVI, the same ESA was identified on 73.8 ± 26.1% of maps. ESA that resulted in AF termination were more likely to be identified on both pre- and post-PVI maps than those associated with cycle length slowing (23 of 24 vs. 16 of 49; p < 0.001). During a follow-up of 18.5 ± 3.7 months, 28 (80%) patients were free from AF/AT., Conclusions: The ablation response at ESA suggests they may be drivers of AF. Ablation guided by STAR mapping produced a favorable clinical outcome and warrants testing through a randomized controlled trial. (Identification, Electro-mechanical Characterisation and Ablation of Driver Regions in Persistent Atrial Fibrillation [STAR MAPPING]; NCT02950844)., (Copyright © 2019 The Authors. Published by Elsevier Inc. All rights reserved.)

Introduction: Stochastic trajectory analysis of ranked signals (STAR) is a novel method for mapping arrhythmia. The aim was to describe its development and validation as a mapping tool., Methods and Results: The method ranks electrodes in terms of the proportion of the time they lead relative to neighboring electrodes and ascribes a predominant direction of activation between electrodes. This was conceived with the aim of mapping atrial fibrillation (AF) drivers. Validation of this approach was performed in stages. First, in vitro simultaneous multi-electrode array and optical mapping were performed on spontaneously fibrillating HL1 cell cultures, to determine if such a method would be able to determine early sites of activation (ESA). A clinical study acquiring unipolar electrograms using a 64-pole basket for the purposes of STAR mapping in patients undergoing atrial tachycardia (AT) ablation. STAR maps were analyzed by physicians to see if arrhythmia mechanisms could be correctly determined. Mapping was then repeated during atrial pacing. STAR mapping of in vitro activation sequences accurately correlated to the optical maps of planar and rotational activation. Thirty-two ATs were mapped in 25 patients. The ESA accurately identified focal/micro-reentrant ATs and the mechanism of macro-reentrant ATs was effectively demonstrated. STAR method accurately identified four pacing sites in all patients., Conclusions: This novel STAR method correlated well with the gold standard of optical mapping in vitro and was able to accurately identify AT mechanisms. Further analysis is needed to determine whether the method might be of use mapping AF., (© 2019 Wiley Periodicals, Inc.)

Pulmonary vein isolation (PVI) has long been held as the cornerstone for atrial fibrillation (AF) ablation. There are patients who do not have successful AF ablations though, especially among those with persistent AF. At the same time, the evidence suggests that ablating beyond the pulmonary veins does not improve success rates. Two possibilities for the incomplete success rates from the procedure are discussed: that more attention needs to be paid to PVI, optimizing delivery of durable, transmural lesions; or alternatively, shifting the focus away from just PVI and addressing the left atrial substrate itself. These two approaches are likely complementary though, and high-density mapping may offer us the ability to undertake them more effectively. The conclusion from this dialogue is that AF is a heterogenous disease and key is to recognize this heterogeneity and respond to it, rather than have a standardized, dogmatic approach. Durable PVI is clearly an important determinant of success but concurrently, we would suggest we need to go beyond this where appropriate to maximize success rates. Clearly the challenge is defining which patients this is appropriate for and how best to do this. Consequently, rather than being 'the' cornerstone of AF ablation, it is more appropriate to consider PVI as 'a' cornerstone of the procedure going forwards and high-density mapping may be the key to optimizing both aspect of the procedure and in so doing improve long term success rates., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2019. For permissions, please email: journals.permissions@oup.com.)

Objectives: This study sought to use a novel panoramic mapping system (CARTOFINDER) to detect and characterize drivers in persistent atrial fibrillation (AF)., Background: Mechanisms sustaining persistent AF remain uncertain., Methods: Patients undergoing catheter ablation for persistent AF were included. A 64-pole basket catheter was used to acquire unipolar signals, which were processed by the mapping system to generate wavefront propagation maps. The system was used to identify and characterize potential drivers in AF pre- and post-pulmonary vein (PV) isolation. The effect of ablation on drivers identified post-PV isolation was assessed., Results: Twenty patients were included in the study with 112 CARTOFINDER maps created. Potential drivers were mapped in 19 of 20 patients with AF (damage to the basket and noise on electrograms was present in 1 patient). Thirty potential drivers were identified all of which were transient but repetitive; 19 were rotational and 11 focal. Twenty-six drivers were ablated with a predefined response in 22 of 26 drivers: AF terminated with 12 and cycle length slowed (≥30 ms) with 10. Drivers with rotational activation were predominantly mapped to sites of low-voltage zones (81.8%). PV isolation had no remarkable impact on the cycle length at the driver sites (138.4 ± 14.3 ms pre-PV isolation vs. 137.2 ± 15.2 ms post-PV isolation) and drivers that had also been identified on pre-PV isolation maps were more commonly associated with AF termination., Conclusions: Drivers were identified in almost all patients in the form of intermittent but repetitive focal or rotational activation patterns. The mechanistic importance of these phenomena was confirmed by the response to ablation.

Objectives: This study sought to assess the impact of ablation power and catheter irrigation during clinical radiofrequency ablation using impedance drop., Background: In preclinical studies, ablation power and catheter irrigation are determinants of ablation efficacy., Methods: Static 30-s left atrial ablations were delivered in patients undergoing their first atrial fibrillation ablation. Impedance drop during ablation (as a measure of efficacy) was compared using the following: the force time integral (FTI); the FTI-P (a cumulative multiple FTI and ablation power), and ablation index (AI), a weighted algorithm including contact force, power, and duration. Comparison was also made between a conventionally irrigated (SmartTouch [ST]) versus surround flow (STSF) contact force-sensing catheter., Results: We analyzed 1,013 ablations. For both catheters, the Spearman correlation was higher between impedance drop and AI (rho = 0.89 ST, 0.84 STSF) than FTI-P (rho = 0.71 ST, 0.53 STSF) or FTI (rho = 0.77 ST, 0.52 STSF); p < 0.0005 for each. STSF ablations had lower minimum catheter tip temperatures (25°C [interquartile range (IQR): 25°C to 27°C] vs. 35°C [IQR: 34°C to 36°C]; p < 0.005), and lesser impedance drop per FTI or AI (p < 0.005 for both). For STSF, impedance drop plateaued sooner than for ST with respect to FTI (184g.s vs. 463g.s) and AI (370 AI vs. 430 AI)., Conclusions: AI is a more complete ablation descriptor than is FTI or FTI-P, reflected by a stronger correlation with impedance drop. STSF ablations have lower impedance drop per AI or FTI than ST ablations do, suggesting different targets should be used if ablating guided by impedance drop with STSF. With ST, ablation beyond 430 AI provides minimal additional biophysical efficacy, suggesting an upper limit to use for clinical ablation., (Copyright © 2017 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Background: The relative importance of focal drivers, multiple wavelets, rotors and endocardial-epicardial circuits in the maintenance of persistent AF remains unclear. Our objective was to characterize AF wavefront (WF) dynamics during persistent AF., Methods: The Ensite 3000 (St Jude Medical) non-contact mapping system was used to map the LA of 15 patients with persistent AF. Wavefronts were classified into planar WFs, rotors or focal WFs. For each new WF the site of origin, the unipolar electrogram, and propagation patterns were determined., Results: AF was characterized by highly unstable patterns of activation with random combinations of 1-2 propagating planar wavefronts alternating with focal activations in a dynamic process. Stable reentry circuits and rotors were never seen. A total of 499 wavefront patterns were analyzed in this study (416 planar wavefronts and 83 focal wavefronts). In an individual patient planar WFs accounted for 67±35% of activations with lifespans of 98±86ms. Focal activations accounted for 29.7±33.5% of activations with lifespans of 76±95ms. The most common sites for new WF generation were the PVs (33%), LA roof (23%), anterior LA (15%), LAA (11%), and posterior LA (8%). The most common unipolar electrogram morphologies observed were QS pattern (34%), rS (29%), CFAE (26%), QR (7%) and Rs (4%), suggesting that WFs may originate from both the endocardial and epicardial surfaces., Conclusion: Human persistent AF is characterized by the formation of highly unstable WFs consisting of various combinations of one to two planar WFs and brief focal activations without any evidence of rotors or sustained focal sources., (Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.)

Background: Contact force (CF) information may improve the safety and efficacy of ablation for paroxysmal atrial fibrillation (PAF)., Objective: The purpose of this study was to assess the impact of CF data on ablation for PAF., Methods: Patients undergoing first-time PAF ablation were randomized at 7 UK centers to ablation with (CF-on) or without (CF-off) CF data available to the operator, using the same ablation catheter and mapping system. An ablation CF of 5-40g was targeted. Pulmonary vein (PV) reconnection was assessed with adenosine at 60 minutes. Follow-up for arrhythmia recurrence was for 1 year with 7-day Holter recordings at 6 and 12 months., Results: One hundred seventeen patients were studied (59 CF-on, 58 CF-off). In the CF-on group, a reduction in acute PV reconnection rates (22% vs 32%, P = .03) but no significant difference in 1-year success rates off antiarrhythmic drugs (49% vs 52%, P = .9) was observed. There was no difference in major complication rates: 2 of 59 (3%) CF-on, 3 of 58 (5%) CF-off (P = .7). Procedural and fluoroscopy times were not significantly different (P>.5). Overall mean CFs per ablation were not different between groups (13.4 [9.1-19.6]g CF-on, 13.4 [7.4-22.4]g CF-off, P = .5), but a greater proportion of readings in the CF-on group were in the target range (80% vs 68%, P<.001)., Conclusion: This randomized multicenter study demonstrated that CF data availability was associated with reduced acute PV reconnection but not improved 1-year success rates, procedural and fluoroscopy times, or complication rates. There was a reduction in extremes of CF, above and below the study target range, suggesting greater CF control during ablation., (Copyright © 2016 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Aims: Catheter ablation of atrial fibrillation (AF) in patients with heart failure (HF) can improve left ventricular (LV) function and HF symptoms. We aimed to investigate whether long-term maintenance of sinus rhythm impacts on hard outcomes such as stroke and death., Methods and Results: An international multicentre registry was compiled from seven centres for consecutive patients undergoing catheter ablation of AF. Long-term freedom from AF was examined in patients with and without HF. The impact of maintaining sinus rhythm on rates of stroke and death was also examined. A total of 1273 patients were included: 171 with HF and 1102 without. Median follow-up was 3.1 years (IQR 2.0-4.3). The final procedure success rate was no different for paroxysmal AF (PAF) (78.7 vs. 85.7%, P = 0.186), but significantly different for persistent AF (57.3 vs. 75.8%, P < 0.001). Multivariate analysis showed that HF independently predicted recurrent arrhythmia [hazard ratio (HR) 1.7, 95% confidence interval (CI) 1.2-2.4, P = 0.002]. New York Heart Association class decreased from 2.3 ± 0.7 at baseline to 1.5 ± 0.8 at follow-up (P < 0.001). Left ventricular ejection fraction (LVEF) increased from 34.3 ± 9.0 to 45.8 ± 12.8% (P < 0.001). Recurrent AF was strongly predictive of stroke or death in HF patients (HR 8.33, 95% CI 1.86-37.7, P = 0.001)., Conclusion: Long-term success rates for persistent (but not paroxysmal) AF ablation are significantly lower in HF patients. Left ventricular function and HF symptoms were improved following ablation. In HF patients, recurrent arrhythmia strongly predicted stroke and death during follow-up., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For permissions please email: journals.permissions@oup.com.)

Background: Catheter ablation for AF is an effective treatment for patients with AF and systolic LV dysfunction; however, the clinical outcome is variable. We evaluated the impact of cardiomyopathy etiology on long-term outcomes post-catheter ablation., Methods: Patients undergoing AF ablation across 3 centers (2 Australian, 1 UK) from 2002 to 2014, with LVEF<45% were evaluated. Patients were stratified into those with known heart disease as a cause of cardiomyopathy (KHD), and those with idiopathic dilated cardiomyopathy (IDCM)., Results: One hundred and one patients (IDCM = 77, KHD = 24) with AF and LVEF <45% underwent AF ablation. The KHD group (ischemic HD in 67%) were older (61 ± 7 vs. 55 ± 11 years, P = 0.005), with a higher CHADS2 score (2.0 ± 0.8 vs. 1.6 ± 0.7, P = 0.016), but otherwise well matched. After mean follow-up of 36 ± 23 months, AF control was greater in the IDCM group (82% vs. 50% in KHD, P < 0.001). On multivariate analysis IDCM was associated with long-term AF control (P = 0.033). The IDCM group had less functional impairment at follow-up (NYHA class 1.5 ± 0.7 vs. 2.0 ± 0.8, P = 0.005) and improved LVEF (50 ± 11% vs. 38 ± 10%, P < 0.001). Super responders (EF improvement >15%) were overwhelmingly in the IDCM group (94% vs. 6%, P < 0.001) with greater AF control (89% vs. 61%, P < 0.001). All-cause mortality was significantly higher in the KHD group (17% vs. 1.3%, P = 0.002)., Conclusion: IDCM was associated with greater AF control, and improvement in symptoms and LVEF compared to patients with KHD post-AF ablation. AF is an important reversible cause of HF in patients with an unexplained CM and catheter ablation an effective treatment option., (© 2015 Wiley Periodicals, Inc.)

Aims: The aim of this study was to evaluate the 'real-world' impact of a novel contact force (CF)-sensing (SmartTouch™, Biosense Webster, Diamond Bar, CA, USA) catheter coupled with an advanced catheter location (ACL) system on fluoroscopy time and fluoroscopy dose during atrial fibrillation (AF) ablation., Methods and Results: This was a retrospective observational cohort study of prospectively collected data of 1515 consecutive patients undergoing paroxysmal AF (PAF) and persistent AF (PerAF) ablation at a single institution between 2009 and 2014. Patients undergoing AF ablation with the SmartTouch catheter and the ACL system (SmartTouch group, n = 510) were compared with those undergoing AF ablation without this technology (control group, n = 1005). The primary outcomes were total fluoroscopy time (min) and fluoroscopy dose as measured by the dose-area product (mGy cm(2)). Secondary endpoints included total procedure time, total ablation time, and major cardiac complications (tamponade, pericardial effusion, and urgent cardiac surgery). The SmartTouch group had significantly lower fluoroscopy times (9.5 vs. 41 min, P < 0.001), radiation doses (1044 vs. 3571 mGy cm(2), P < 0.001), and shorter procedural time (195 vs. 240 min, P < 0.001) when compared with the control group. This was statistically significant for both PAF and PerAF ablations and for both de novo and redo AF procedures. After a learning curve, a median fluoroscopy time of 3.5 min (interquartile range 6) for all AF ablations was achieved. There was no difference in the rate of cardiac complications (∼ 1.5%)., Conclusion: SmartTouch™ CF-sensing catheter use with ACL™ during AF ablation significantly reduces fluoroscopy times by 77%, radiation dose by 71%, and procedural time by 19% but does not improve overall safety or the risk of cardiac complications., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.)

Introduction: Catheter ablation of paroxysmal AF using the Cryoballoon (CRYO) has yielded similar success rates to conventional wide encirclement using radiofrequency catheter ablation (RFCA), but randomized data are lacking. Pilot data suggested a high success rate with a combined approach (COMBINED) using wide encirclement with RFCA followed by 2 CRYO applications to each vein. We compared these 3 strategies in a randomized controlled trial., Methods and Results: Patients undergoing first time paroxysmal AF ablation were randomized to RFCA, CRYO, or COMBINED. Patients were followed up at 3, 6, and 12 months with 7 days of ambulatory ECG monitoring. Success was defined as freedom from arrhythmia without antiarrhythmic drugs after a single procedure. A total of 237 patients were randomized. Success at 1 year was achieved in 47% in the RFCA group, 67% in the CRYO group, and 76% in the COMBINED group (P < 0.001 for RFCA vs. CRYO, P<0.001 for RFCA vs. COMBINED, and P = 0.220 for CRYO vs. COMBINED). Procedure time was 211 (IQR 174-256) minutes for RFCA compared to 167 (136-202) minutes for CRYO and 278 (243-327) minutes for COMBINED (P < 0.001 for RFCA vs. COMBINED, RFCA vs. CRYO, and CRYO vs. COMBINED groups)., Conclusions: Pulmonary vein isolation for paroxysmal AF is faster with CRYO and results in a higher single procedure success rate than conventional point by point RFCA. The COMBINED approach was not superior to CRYO alone., (© 2015 Wiley Periodicals, Inc.)

Background: During left atrial mapping, optimal contact parameters minimizing variation secondary to catheter contact are not established., Methods and Results: Across 30 patients undergoing first-time atrial fibrillation ablation, 1965 stable mapping points (1409 atrial fibrillation, 556 sinus rhythm), comprising 8-s contact force (CF) and bipolar electrogram data were analyzed. Points were taken in groups at locations with CF or catheter orientation actively changed between acquisitions. Complexes were less positive at higher CF (Spearman ρ, -0.2; P<0.005, both rhythms). Increasing CF at a location significantly increased complex size, but only where initial CF was <10 g, and if the change was ≥4.5 g in sinus rhythm and ≥8 g in atrial fibrillation (P<0.0005, both rhythms): if initial CF was ≥10 g, no change was observed, regardless of CF change (P>0.05, both). Atrial ectopics during sinus rhythm were observed more frequently when CF was ≥10 g (P<0.0005). Increasing CF at a location was associated with an increase in the complex fractionated atrial electrogram interval confidence level score, but only if initial CF was <10 g and CF increased ≥8 g (P=0.003). The dominant frequency and organization index were unaffected by CF (P>0.1 for both). Changing catheter orientation from perpendicular to parallel in atrial fibrillation was associated with smaller, more positive complexes (P=0.001 for both), but no changes in complex fractionated atrial electrogram scores, dominant frequency or organization index (P>0.08 for each)., Conclusions: During left atrial electrogram mapping, including complex fractionated atrial electrogram but not spectral parameter mapping, CF and catheter orientation influence results: consequently, mapping CFs should be ≥10 g to negate the influence of CF., Clinical Trials Registration: URL: http://clinicaltrials.gov/. Unique identifier: NCT01587404., (© 2015 American Heart Association, Inc.)

Introduction: Contact force sensing (CFS) technology improves acute pulmonary vein isolation durability; however, its impact on the clinical outcome of ablating atrial fibrillation (AF) is unknown., Methods and Results: First time AF ablation procedures employing CFS from 4 centers were matched retrospectively to those without CFS in a 1:2 manner by type of AF. Freedom from atrial tachyarrhythmia was defined as the primary outcome measure, and fluoroscopy time the secondary outcome measure. Nineteen possible explanatory variables were tested in addition to CFS. A total of 600 AF ablation procedures (200 using CFS and 400 using non-CFS catheters) performed between 2010 and 2012 (46% paroxysmal, 36% persistent, 18% long-lasting persistent) were analyzed. The mean follow-up duration was 11.4 ± 4.7 months-paroxysmal AF 11.2 ± 4.1 CFS versus 11.3 ± 3.9 non-CFS (P = 0.745)-nonparoxysmal AF 10.4 ± 4.5 CFS versus 11.9 ± 5.4 non-CFS (P = 0.015). The use of a CFS catheter independently predicted clinical success in ablating paroxysmal AF (HR 2.24 [95% CIs 1.29-3.90]; P = 0.004), but not nonparoxysmal AF (HR 0.73 [0.41-1.30]; P = 0.289) in a multivariate analysis that included follow-up duration. Among all cases, the use of CFS catheters was associated with reduced fluoroscopy time in multivariate analysis (reduction by 7.7 [5.0-10.5] minutes; P < 0.001). Complication rates were similar in both groups., Conclusions: At medium-term follow-up, CFS catheter technology is associated with significantly improved outcome of first time catheter ablation of paroxysmal AF, but not nonparoxysmal AF. Fluoroscopy time was lower when CFS technology was employed in all types of AF ablation procedures., (© 2014 Wiley Periodicals, Inc.)

Background: In preclinical studies, catheter contact force (CF) during radiofrequency ablation correlates with the subsequent lesion size. We investigated the impact of steerable sheaths on ablation CF, its consistency, and wide area circumferential ablation (WACA) line reconnection sites., Methods and Results: Five thousand and sixty-four ablations were analyzed across 60 patients undergoing first-time ablation for persistent AF using a CF-sensing catheter: 19 manual nonsteerable sheath (Manual-NSS), 11 manual steerable sheath, and 30 robotic steerable sheath (Sensei, Hansen Medical Inc.) procedures were studied. Ablation CFs were higher in the steerable sheath groups for all left atrial ablations and also WACA ablations specifically (P < 0.006), but less consistent per WACA segment (P < 0.005). There were significant differences in the CFs around both WACAs by group: in the left WACA CFs were lower with Manual-NSS, other than at the anterior-inferior and posterior-superior regions, and lower in the right WACA, other than the anterior-superior region. There was a difference in the proportion of segments chronically reconnecting across groups: Manual-NSS 26.5%, manual steerable sheath 4.6%, robotic 12% (P < 0.0005). The left atrial appendage/PV ridge and right posterior wall were common sites of reconnection in all groups., Conclusions: Steerable sheaths increased ablation CF; however, there were region-specific heterogeneities in the extent of increment, with some segments where they failed to increase CF. Steerable sheath use was associated with reduced WACA-segment reconnection. It may be that the benefits of steerable sheath use in terms of higher CFs could be translated to improved clinical outcomes if regional weaknesses of this technology are taken into account during ablation procedures., (© 2014 Wiley Periodicals, Inc.)

Introduction: Preclinical work suggests factors including catheter orientation and contact consistency during individual radiofrequency ablations influence lesion size. Our aim was to investigate factors affecting catheter contact in the left atrium (LA) and their effects on ablation., Methods and Results: A total of 2,298 8-second static LA mapping points were studied in 30 patients undergoing ablation for AF (16 in AF, 14 sinus rhythm [SR], 18 remote robotic navigation [RRN] procedures) using a contact force (CF) sensing catheter. CF variability (CFV: difference between 20 Hz-sampled CF waveform mean peak and trough) increased with mean CF, Spearman's ρ = 0.6, P < 0.005. Catheter drift correlated weakly with CF (Pearson's correlation -0.06, P = 0.005). CFV was higher in SR than AF and with RRN (P < 0.001). In AF, there was less catheter drift for RRN than manual navigation points but the converse was true in SR. In 747 static 30 second LA ablations, the influence of contact parameters on ablation efficacy was compared by multivariate analysis of impedance drop during ablation: a lesser drop suggesting reduced efficacy. For a given force time integral (FTI), increased CFV (>5 g) and locational drift (>3.5 mm), perpendicular contact, SR and RRN usage were associated with a lesser impedance drop with ablation (P < 0.005 for each), suggesting reduced efficacy., Conclusions: Beyond the FTI, the quality of catheter contact influences ablation efficacy, and clinical catheter contact is affected by multiple factors, including the atrial rhythm and catheter navigation mode. Maximal efficacy is provided by parallel contact with CFV ≤5 g, catheter drift ≤3.5 mm, and manual navigation., (© 2014 Wiley Periodicals, Inc.)

Background: Catheter ablation of atrial fibrillation (AF) is a physically demanding procedure for the operator, involving radiation exposure, and has limited success rates. Remote robotic navigation (RRN) may offer benefit to the procedure, though only 1 previous small randomized trial has assessed this., Objective: This study aimed to investigate the impact of RRN on 1-year single-procedure success rates., Methods: RRN was compared to manual ablation in a randomized control trial setting by using an intention-to-treat analysis., Results: A total of 157 patients underwent ablation (116/157 (74%) persistent AF; 67/116 (58%) of these long-standing persistent AF). There were no significant differences between the RRN and manual groups with respect to 1-year single-procedure success rates (19/78 (24%) and 26/78 (33%), respectively; P = .29), acute wide area circumferential ablation reconnection rates, complication rates, or procedure times. On multivariable analysis, fluoroscopy times were significantly shorter in the RRN group. The number of catheter displacements during ablation was lower in the RRN group, as was subjectively assessed operator fatigue. The crossover rate from RRN to manual ablation was 11/78 (14%), mainly secondary to technical problems with the RRN system. A learning curve was evident for RRN ablation: the fluoroscopy and procedure times were significantly lower after the first 10 cases in an operator's experience., Conclusion: This randomized trial showed no difference in the success rate for catheter ablation of AF between a RRN and manual approach. The results highlight the learning curve for RRN ablation and suggest that the use of this technology leads to an improvement in fluoroscopy times, catheter stability, and operator fatigue., (Copyright © 2014 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Background: Catheter-based contact force sensing (CFS) technology gives detailed information regarding contact between the catheter tip and myocardium. This may result in more effective ablation procedures. The primary objective of this study was comparison of remote robotic navigation (RRN) and Manual CFS ablation. The secondary objective was to compare CFS with non-CFS ablation for both navigation modes., Methods: Prospective registries of consecutive cases undergoing their first ablation for persistent atrial fibrillation (AF) from six hospitals in the United Kingdom and South Africa were analyzed: 50 Manual/CFS and 50 RRN/CFS cases were included. Historical control non-CFS ablation patients were matched by propensity score, giving a total 200 patient cohort., Results: RRN/CFS was associated with improved single procedure 1-year success rates (64% vs 36%, P = 0.01) and shorter fluoroscopy times (41% reduction, P < 0.0005) than Manual/CFS ablation, without any difference in procedure times (P = 0.8). The mean contact force was higher in RRN/CFS than Manual/CFS cases (16 [15-18 g] vs 13 [12-15 g], respectively, P = 0.003). Compared with non-CFS historical controls, CFS cases had higher 1-year success rates for RRN (64% vs 36%, P = 0.01), but not Manual ablation (36% vs 38%, P = 1). Procedure times were reduced for CFS cases (20%, P < 0.005 both navigation modes), as were fluoroscopy times (Manual: 43%, RRN 83%, P < 0.005 for both). There were no differences in rates of major or minor complications for either comparison (P > 0.5)., Conclusions: A combination of RRN and CFS is associated with improved success rates at 1 year and fluoroscopy times for persistent AF ablation, compared with Manual ablation and non-CFS RRN ablation., (©2014 Wiley Periodicals, Inc.)

Background: Restoring sinus rhythm in patients with heart failure (HF) and atrial fibrillation (AF) may improve left ventricular (LV) function and HF symptoms. We sought to compare the effect of a catheter ablation strategy with that of a medical rate control strategy in patients with persistent AF and HF., Methods and Results: Patients with persistent AF, symptomatic HF, and LV ejection fraction <50% were randomized to catheter ablation or medical rate control. The primary end-point was the difference between groups in LV ejection fraction at 6 months. Baseline LV ejection fraction was 32±8% in the ablation group and 34±12% in the medical group. Twenty-six patients underwent catheter ablation, and 24 patients were rate controlled. Freedom from AF was achieved in 21/26 (81%) at 6 months off antiarrhythmic drugs. LV ejection fraction at 6 months in the ablation group was 40±12% compared with 31±13% in the rate control group (P=0.015). Ablation was associated with better peak oxygen consumption (22±6 versus 18±6 mL/kg per minute; P=0.014) and Minnesota living with HF questionnaire score (24±22 versus 47±22; P=0.001) compared with rate control., Conclusions: Catheter ablation is effective in restoring sinus rhythm in selected patients with persistent AF and HF, and can improve LV function, functional capacity, and HF symptoms compared with rate control. Clinical Trial Registration- URL: http://www.clinicaltrials.gov. Unique identifier: NCT01411371.

Background: In animal studies of radiofrequency ablation, lesion sizes plateau as the maximum lesion size is reached for an ablation. Lesion parameters are not available in clinical ablations, but preclinical work suggests that these correlate with impedance drop and electrogram attenuation. Characterization of the relationships between catheter contact force, ablation duration, and these surrogate markers of lesion formation may allow us to define targets for effective ablation., Methods and Results: Fifteen patients undergoing first-time radiofrequency ablation for nonparoxysmal atrial fibrillation were studied. All were in atrial fibrillation at the time of the procedure. Ablations were performed with an irrigated-tip contact force-sensing catheter in temperature-controlled mode (temperature limited to 48°C, power to 30 W). Included were 285 left atrial static ablations, 247 with additional impedance data. The ablation force time integral (FTI) correlated with the attenuation of the electrogram with ablation (Spearman ρ, -0.14; P=0.02): the relationship plateauing from 500 g·s, a reduction in the electrogram amplitude of 20%. The FTI also correlated with the impedance drop during ablation (Spearman ρ, 0.79; P<0.0005): the relationship was logarithmic, the reduction in the impedance with an increasing FTI also plateauing from 500 g·s, an impedance drop of 7.5%. The ablation duration affected the impedance drop at an FTI if the duration was <10 s. Beyond this time point, the FTI achieved rather than the ablation duration or mean contact force applied determined the impedance drop., Conclusions: During nonparoxysmal atrial fibrillation ablation, an FTI of 500 g·s should be targeted with ablation duration of ≥10 s. Clinical Trials Registration- URL: http://clinicaltrials.gov/. Unique Identifier: NCT01587404.

Abstract: Introduction: This study sought to validate a novel wavefront mapping system utilizing whole‐chamber basket catheters (CARTOFINDER, Biosense Webster). The system was validated in terms of (1) mapping atrial‐paced beats and (2) mapping complex wavefront patterns in atrial tachycardia (AT). Methods and results: Patients undergoing catheter ablation for AT and persistent AF were included. A 64‐pole‐basket catheter was used to acquire unipolar signals that were processed by CARTOFINDER mapping system to generate dynamic wavefront propagation maps. The left atrium was paced from four sites to demonstrate focal activation. ATs were mapped with the mechanism confirmed by conventional mapping, entrainment, and response to ablation. Twenty‐two patients were included in the study (16 with AT and 6 with AF initially who terminated to AT during ablation). In total, 172 maps were created with the mapping system. It correctly identified atrial‐pacing sites in all paced maps. It accurately mapped 9 focal/microreentrant and 18 macroreentrant ATs both in the left and right atrium. A third and fourth observer independently identified the sites of atrial pacing and the AT mechanism from the CARTOFINDER maps, while being blinded to the conventional activation maps. Conclusions: This novel mapping system was effectively validated by mapping focal activation patterns from atrial‐paced beats. The system was also effective in mapping complex wavefront patterns in a range of ATs in patients with scarred atria. The system may therefore be of practical use in the mapping and ablation of AT and could have potential for mapping wavefront activations in AF. [ABSTRACT FROM AUTHOR]

Catheters able to measure the force and vector of contact between the catheter tip and myocardium are now available. Pre-clinical work has established that the degree of contact between the radiofrequency ablation catheter and myocardium correlates with the size of the delivered lesion. Excess contact is associated with steam pops and perforation. Catheter contact varies within the left atrium secondary to factors including respiration, location, atrial rhythm and the trans-septal catheter delivery technology used. Compared with procedures performed without contact force (CF)-sensing, the use of this technology has, in some studies, been found to improve complication rates, procedure and fluoroscopy times, and success rates. However, for each of these parameters there are also studies suggesting a lack of difference from the availability of CF data. Nevertheless, CF-sensing technology has been adopted as a standard of care in many institutions. It is likely that use of CF-sensing technology will allow for the optimization of each individual radiofrequency application to maximize efficacy and procedural safety. Recent work has attempted to define what these optimal targets should be, and approaches to do this include assessing for sites of pulmonary vein reconnection after ablation, or comparing the impedance response to ablation. Based on such work, it is apparent that factors including mean CF, force time integral (the area under the force-time curve) and contact stability are important determinants of ablation efficacy. Multicenter prospective randomized data are lacking in this field and required to define the CF parameters required to produce optimal ablation. [ABSTRACT FROM AUTHOR]