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Introduction: Atrial Fibrillation (AF) is a common arrhythmia often comorbid with systolic or diastolic heart failure (HF). Catheter ablation is a more effective treatment for AF with concurrent left ventricular dysfunction, however, the optimal timing of use in these patients is unknown. Methods: All patients that received a catheter ablation for AF(n = 9979) with 1 year of follow‐up within the Intermountain Healthcare system were included. Patients with were identified by the presence of structural disease by ejection fraction (EF): EF ≤ 35% (n = 1024) and EF > 35% (n = 8955). Recursive partitioning categories were used to separate patients into clinically meaningful strata based upon time from initial AF diagnosis until ablation: 30–180(n = 2689), 2:181–545(n = 1747), 3:546–1825(n = 2941), and 4:>1825(n = 2602) days. Results: The mean days from AF diagnosis to first ablation was 3.5 ± 3.8 years (EF > 35%: 3.5 ± 3.8 years, EF ≤ 35%: 3.4 ± 3.8 years, p =.66). In the EF > 35% group, delays in treatment (181–545 vs. 30–180, 546–1825 vs. 30–180, >1825 vs. 30–180 days) increased the risk of death with a hazard ratio (HR) of 2.02(p <.0001), 2.62(p <.0001), and 4.39(p <.0001) respectively with significant risks for HF hospitalization (HR:1.44–3.69), stroke (HR:1.11–2.14), and AF recurrence (HR:1.42–1.81). In patients with an EF ≤ 35%, treatment delays also significantly increased risk of death (HR 2.07–3.77) with similar trends in HF hospitalization (HR:1.63–1.09) and AF recurrence (HR:0.79–1.24). Conclusion: Delays in catheter ablation for AF resulted in increased all‐cause mortality in all patients with differential impact observed on HF hospitalization, stroke, and AF recurrence risks by baseline EF. These data favor earlier use of ablation for AF in patients with and without structural heart disease. [ABSTRACT FROM AUTHOR]

Comparison of Remote Magnetic Irrigated Tip Background Remote magnetic navigation (RMN) and contact force (CF) sensing technologies have been utilized in an effort to improve safety and efficacy of catheter ablation. A comparative analysis of the relative short- and long-term outcomes of AF patients has not been performed. As such, we comparatively evaluated the safety and efficacy of these technologies. Methods A total of 627 patients who underwent catheter ablation with either a manual irrigated tip catheter: (312, 49.8%) or by RMN: (315, 50.2%) were included in this single-center cohort study. Patients treated with CF (59) were analyzed separately as well. One- and 3-year endpoints included death, HF hospitalization, stroke, TIA, and atrial flutter or AF recurrence. Results Age averaged 65.1 ± 10.7 years and 64.1% male. One- and 3-year endpoints of death, HF hospitalization, stroke, TIA, and atrial flutter or AF recurrence were statistically similar between manual and RMN treated groups. Fluoroscopy times were significantly lower in the RMN group compared to the manual ablation group (8.47 ± 0.45 vs. 9.63 ± 4.06 minutes, P < 0.0001). CF guided patients had 1-year recurrence rate of AF/atrial flutter statistically identical to patients treated with RMN (36.8% vs. 38.6%; P = 1.00). Conclusion RMN results in outcomes similar to manual navigation. The addition of CF sensing catheters did not improve relative procedural outcome or safety profile in comparison to RMN guided ablation in this large observational study of AF ablation. [ABSTRACT FROM AUTHOR]

Background: There are a paucity of data about the long-term natural history of adult Wolff-Parkinson-White syndrome (WPW) patients in regard to risk of mortality and atrial fibrillation. We sought to describe the long-term outcomes of WPW patients and ascertain the impact of ablation on the natural history.Methods and Results: Three groups of patients were studied: 2 WPW populations (ablation: 872, no ablation: 1461) and a 1:5 control population (n=11 175). Long-term mortality and atrial fibrillation rates were determined. The average follow-up for the WPW group was 7.9±5.9 (median: 6.9) years and was similar between the ablation and nonablation groups. Death rates were similar between the WPW group versus the control group (hazard ratio, 0.96; 95% confidence interval, 0.83-1.11; P=0.56). Nonablated WPW patients had a higher long-term death risk compared with ablated WPW patients (hazard ratio, 2.10; 95% confidence interval: 1.50-20.93; P<0.0001). Incident atrial fibrillation risk was higher in the WPW group compared with the control population (hazard ratio, 1.55; 95% confidence interval, 1.29-1.87; P<0.0001). Nonablated WPW patients had lower risk than ablated patients (hazard ratio, 0.39; 95% confidence interval, 0.28-0.53; P<0.0001).Conclusions: Long-term mortality rates in WPW patients are low and similar to an age-matched and gender-matched control population. WPW patients that underwent the multifactorial process of ablation had a lower mortality compared to nonablated WPW patients. Atrial fibrillation rates are high long-term, and ablation does not reduce this risk. [ABSTRACT FROM AUTHOR]

Catheter Ablation and Long-Term Outcomes Background Catheter ablation of atrial fibrillation (AF) is an established therapy for symptomatic patients. The long-term efficacy and impact of catheter ablation among patients with severe systolic heart failure (SHF) requires additional study to understand if outcomes achieved at 1 year are maintained and mechanisms of AF recurrence. Methods Three groups with SHF and 5 years of follow-up were matched 1:4:4 by age (±5 years) and sex: AF ablation patients receiving their first ablation (n = 267), AF patients that did not receive an ablation (n = 1,068), and SHF patient without AF (n = 1,068). SHF was based upon clinical diagnosis and an ejection fraction (EF) ≤35%. Patients were followed for 5-year primary outcomes of AF recurrence, heart failure, stroke, death, and cardiac function. Results At 5 years, 60.7% of patients had clinical recurrence of AF. Diabetes and a prior heart attack were significant predictors of long-term risk of AF recurrence. Long-term mortality rates were 27%, 55%, 50%, in the AF ablation, AF, and no AF groups, respectively (P < 0.0001), with the lower rates attributed to lower cardiovascular mortality. At 5 years, there was no difference in EF, yet HF hospitalizations were lower following AF ablation compared to patients with AF and no ablation. Stroke rates at 5 years trended to be lower in the AF ablation group, but the difference was not statistically significant. Conclusion Recurrence rates of AF in patients with SHF after ablation are common at 5 years with an anticipated ongoing increase. Long-term AF-related comorbidities tended to be less in the AF ablation group. [ABSTRACT FROM AUTHOR]

AF Ablation in Pulmonary Vein Stumps Background Pulmonary vein isolation (PVI) of the remnant pulmonary vein (PV) stumps in pneumonectomy patients has not been well characterized. Methods This is a multicenter observational study of patients with a remnant PV stump after pneumonectomy. Consecutive patients with a history of pneumonectomy and who had undergone RF ablation for drug refractory AF were identified from the AF database at the participating institutions. Results There were 15 patients in whom pneumonectomy was performed, for resection of tumors in 10, infection in 4, and bullae in 1 patient and who underwent RF ablation for AF. The mean age was 63 ± 7 years. The stumps were from the right lower PV in 5, left upper PV in 5, left lower PV in 3, and right upper PV in 2 patients. All the PV stumps were electrically active with PV potentials and 9 (60%) of them had triggered activity. PVI was performed in 14 and focal isolation in 1 patient. At 1-year follow-up, 80% were free of AF, off of antiarrhythmic medications. Conclusion PV stumps in AF patients with previous pneumonectomy are electrically active and are frequently the sites of active firing. Isolation of these PV stumps can be accomplished safely and effectively using catheter ablation with no practical concern for PV stenosis or compromising PV stump integrity. [ABSTRACT FROM AUTHOR]

Multicenter FIRM Registry for AF Introduction The success of pulmonary vein isolation (PVI) for atrial fibrillation (AF) may be improved if stable AF sources identified by Focal Impulse and Rotor Mapping (FIRM) are also eliminated. The long-term results of this approach are unclear outside the centers where FIRM was developed; thus, we assessed outcomes of FIRM-guided AF ablation in the first cases at 10 experienced centers. Methods We prospectively enrolled n = 78 consecutive patients (61 ± 10 years) undergoing FIRM guided ablation for persistent (n = 48), longstanding persistent (n = 7), or paroxysmal (n = 23) AF. AF recordings from both atria with a 64-pole basket catheter were analyzed using a novel mapping system (Rhythm ViewTM; Topera Inc., CA, USA). Identified rotors/focal sources were ablated, followed by PVI. Results Each institution recruited a median of 6 patients, each of whom showed 2.3 ± 0.9 AF rotors/focal sources in diverse locations. 25.3% of all sources were right atrial (RA), and 50.0% of patients had ≥1 RA source. Ablation of all sources required a total of 16.6 ± 11.7 minutes, followed by PVI. On >1 year follow-up with a 3-month blanking period, 1 patient lost to follow-up (median time to 1st recurrence: 245 days, IQR 145-354), single-procedure freedom from AF was 87.5% (patients without prior ablation; 35/40) and 80.5% (all patients; 62/77) and similar for persistent and paroxysmal AF (P = 0.89). Conclusions Elimination of patient-specific AF rotors/focal sources produced freedom-from-AF of ≈80% at 1 year at centers new to FIRM. FIRM-guided ablation has a rapid learning curve, yielding similar results to original FIRM reports in each center's first cases. [ABSTRACT FROM AUTHOR]

Atrial Pacing in Heart Failure. Introduction: Cardiac resynchronization therapy (CRT) efficacy trials to date used atrial-synchronous biventricular pacing wherein there is no or minimal atrial pacing. However, bradycardia and chronotropic incompetence are common in this patient population. This trial was designed to evaluate the effect of atrial support pacing among heart failure patients receiving a CRT defibrillator. Methods and Results: PEGASUS CRT was a multicenter, 3-arm, randomized study. At 6 weeks, patients were randomized to DDD mode at a lower rate of 40 bpm (DDD-40; control arm), or one of the following 2 treatment arms: DDD-70, or DDDR-40. The primary endpoint was a clinical composite endpoint that included all-cause mortality, heart failure events, NYHA functional class, and patient global self-assessment. Subjects were classified as improved, unchanged, or worsened at 12 months. There were 1,433 patients randomized, of whom 66% were male, mean age was 67 ± 11 years, and mean left ventricular ejection fraction was 23 ± 7%. The average follow-up time was 10.5 ± 3.5 months and 1,309 patients contributed to the primary endpoint. No significant differences were observed in the composite endpoint between either of the 2 treatment arms compared to the control arm (P>0.05 for both comparisons). Additionally, there were no differences among the groups in mortality or heart failure events. Conclusion: In advanced heart failure patients treated with CRT, atrial support pacing did not improve clinical outcomes compared to atrial tracking. However, atrial pacing did not adversely affect mortality or heart failure events. (J Cardiovasc Electrophysiol, Vol. 23, pp. 1317-1325, December 2012) [ABSTRACT FROM AUTHOR]

Background: There are limited options for patients who present with antiarrhythmic-drug (AAD)-refractory ventricular tachycardia (VT) with recurrent implantable cardioverter defibrillator (ICD) shocks. Ranolazine is a drug that exerts antianginal and antiischemic effects and also acts as an antiarrhythmic in isolation and in combination with other class III medications. Ranolazine may be an option for recurrent AAD-refractory ICD shocks secondary to VT, but its efficacy, outcomes, and tolerance are unknown. Methods and Results: Twelve patients (age 65 ± 9.7 years) were treated with ranolazine. Eleven (92%) were male, and 10 (83%) had ischemic heart disease with an average ejection fraction of 0.34 ± 0.13. All patients were on a class III AAD (11 amiodarone, one sotalol), with six (50%) receiving mexilitene or lidocaine. Five patients had a prior ablation and two were referred for a VT ablation at the index presentation. The QRS increased nonsignificantly from 128 ± 31 ms to 133 ± 31 ms, and the QTc increased nonsignificantly from 486 ± 32 ms to 495 ± 31 ms after ranolazine initiation. Over a follow-up of 6 ± 6 months, 11 (92%) patients had a significant reduction in VT and no ICD shocks were observed. VT ablation was not required in those referred. In two patients, gastrointestinal side effects limited long-term use. Of these two patients, one died due to progressive heart failure. In one patient, severe hypoglycemia limited dosing to 500 mg daily, but this was sufficient for VT control. Conclusion: Ranolazine proved effective in reducing VT burden and ICD shocks in patients with AAD-refractory VT. Ranolazine should be further tested for this indication and considered for clinical application when other options have proven ineffective. (PACE 2011; 34:1600-1606) [ABSTRACT FROM AUTHOR]

Outcomes in Patients With AF. Introduction: Atrial fibrillation (AF) adversely impacts mortality, stroke, heart failure, and dementia. AF ablation eliminates AF in most patients. We evaluated the long-term impact of AF ablation on mortality, heart failure (HF), stroke, and dementia in a large system-wide patient population. Methods: A total of 4,212 consecutive patients who underwent AF ablation were compared (1:4) to 16,848 age/gender matched controls with AF (no ablation) and 16,848 age/gender matched controls without AF. Patients were enrolled from the large ongoing prospective Intermountain AF study and were followed for at least 3 years. Results: Of the 37,908 patients, mean age 65.0 ± 13 years, 5,667 (14.9%) died, 1,296 (3.4%) had a stroke, and 1,096 (2.9%) were hospitalized for HF over >3 years of follow-up. AF ablation patients were less likely to have diabetes, but were more likely to have hypertension, HF, and significant valvular heart disease. AF ablation patients had a lower risk of death and stroke in comparison to AF patients without ablation. Alzheimer's dementia occurred in 0.2% of the AF ablation patients compared to 0.9% of the AF no ablation patients and 0.5% of the no AF patients (P < 0.0001). Other forms of dementia were also reduced significantly in those treated with ablation. Compared to patients with no AF, AF ablation patients had similar long-term rates of death, dementia, and stroke. Conclusions: AF ablation patients have a significantly lower risk of death, stroke, and dementia in comparison to AF patients without ablation. AF ablation may eliminate the increased risk of death and stroke associated with AF. (J Cardiovasc Electrophysiol, Vol. 22, pp. 839-845, August 2011) [ABSTRACT FROM AUTHOR]

Strategy of Rapid Cardioversion. Background: The significance of early recurrent atrial tachyarrhythmias after atrial fibrillation (AF) ablation is unclear. Atrial remodeling driven by these tachyarrhythmias can result in electrical, contractile, and structural changes that may impair long-term therapy success. Aggressive attempts to restore sinus rhythm in the temporal period of healing after ablation might improve outcomes. Methods: A total of 1,759 AF ablations were performed at Intermountain Medical Center or LDS Hospital. A total of 455 of those were among patients requiring repeat ablations. Patients were instructed to take their pulse daily and, if greater than 100 bpm or irregular, present the following business day fasting to the clinic for evaluation and cardioversion if AF or atrial flutter (AFL) were present. Results: Of the ablations performed, a total of 515 (29%, age: 65.6 ± 11.2 years, male: 57.9%) developed AF/AFL that required cardioverison. The majority of these arrhythmias first occurred in the initial 90 days (63.7%) postablation. During this period, 62.8% were on an antiarrhythmic drug (AAD). Only 25.1% were using an AAD at 3 months. The majority of ablations (75.6%) who experienced AF/AFL within the first 90 days after ablation were in sinus rhythm with no AAD at 1 year. Further, 48% of those with the first recurrence from 90 to 180 days were in sinus rhythm with no AAD at 1 year. Conclusions: The time at which the first recurrence of AF/AFL occurs impacts long-term outcomes. An aggressive strategy of rapid cardioversion postablation reduces the significance of recurrent AF/AFL during the first 6 months. (J Cardiovasc Electrophysiol, Vol. 22, pp. 761-766, July 2011) [ABSTRACT FROM AUTHOR]

The authors reflect on phrenic nerve pacing during atrial ablation and on the article "Electrical Isolation of the Superior Vena Cava Using Upstream Phrenic Pacing to Avoid Phrenic Nerve Injury" by T. Kimura et al. They suggest that Kimura et al should be congratulated on informing readers about the benefits of using phrenic nerve pacing to avoid phrenic nerve injury during ablation. They argue that physicians who perform ablation should be familiar with the benefits of phrenic pacing.

Background: Catheter ablation is an increasingly used treatment for symptomatic atrial fibrillation (AF). However, there are limited prospective, nationwide data on patient selection and procedural characteristics. This study describes patient characteristics, techniques, treatment patterns, and safety outcomes of patients undergoing AF ablation.Methods: A total of 3139 patients undergoing AF ablation between 2016 and 2018 in the Get With The Guidelines-Atrial Fibrillation registry from 24 US centers were included. Patient demographics, medical history, procedural details, and complications were abstracted. Differences between paroxysmal and patients with persistent AF were compared using Pearson χ2 and Wilcoxon rank-sum tests.Results: Patients undergoing AF ablation were predominantly male (63.9%) and White (93.2%) with a median age of 65. Hypertension was the most common comorbidity (67.6%), and patients with persistent AF had more comorbidities than patients with paroxysmal AF. Drug refractory, paroxysmal AF was the most common ablation indication (class I, 53.6%) followed by drug refractory, persistent AF (class I, 41.8%). Radiofrequency ablation with contact force sensing was the most common ablation modality (70.5%); 23.7% of patients underwent cryoballoon ablation. Pulmonary vein isolation was performed in 94.6% of de novo ablations; the most common adjunctive lesions included left atrial roof or posterior/inferior lines, and cavotricuspid isthmus ablation. Complications were uncommon (5.1%) and were life-threatening in 0.7% of cases.Conclusions: More than 98% of AF ablations among participating sites are performed for class I or class IIA indications. Contact force-guided radiofrequency ablation is the dominant technique and pulmonary vein isolation the principal lesion set. In-hospital complications are uncommon and rarely life-threatening. [ABSTRACT FROM AUTHOR]

The authors reflect on the article "Clinical Predictors of Arrhythmia Recurrences Following Pulmonary Vein Antrum Isolation for Atrial Fibrillation (Predicting Arrhythmia Recurrence Post- PVAI) by Y. Khaykin, R. Oosthuizen, L. Zarnett, V. Essebag, R. Parkash, C. Seabrook, M. Beardsall, B. Tsang, Z. Wulffhart and A. Verma. They suggest that the article provides an excellent analysis of research. They argue that the article has important implications for the care of atrial fibrillation patients.