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Background: The healing response to cardiac implantable electronic device (CIED) implantation results in inflammation that can lead to fibrous pocket formation, which may disrupt pocket healing or complicate future interventions., Objective: The purpose of this study was to assess CIED pocket healing with use of the second-generation TYRX absorbable antibacterial envelope (T2), the next-generation (NG) TYRX absorbable antibacterial envelope under development, and the CanGaroo® extracellular matrix envelope (ECM) compared to no envelope., Methods: A total of 110 CIEDs were implanted in an ovine model, either with (T2, NG, or ECM) or without envelopes. Histopathologic and morphometric analyses were completed at several timepoints after implant (3 days, 7 days, 4 weeks, 12 weeks, 24 weeks). An independent pathologist completed a blinded histopathology assessment of the pockets., Results: TYRX (T2/NG) pockets showed similar inflammatory and healing profiles to controls with more rapid provisional matrix formation compared to controls and ECM. ECM pockets exhibited increased acute (3 and 7 days) and chronic (24 weeks) inflammation. T2/NG had almost complete (T2) or complete (NG) absorption by week 12. ECM remained present at week 24 and was associated with significantly thicker capsules (ECM 0.80 ± 0.14 mm; NG 0.37 ± 0.10 mm; control 0.56 ± 0.17 mm)., Conclusion: Compared to ECM, pockets with TYRX showed less inflammation, more rapid provisional matrix formation, faster absorption, and thinner capsules. TYRX pockets had low inflammation comparable to controls with accelerated provisional matrix deposition and tissue adhesion. The healing response to CIEDs used with TYRX fosters the formation of a well-healed pocket, which may bring patient benefit beyond its proven infection reduction., Competing Interests: Disclosures Dr Virmani reports being on the advisory board for Medtronic. Dr Philippon reports research grants and lectures for Medtronic. Dr Mittal reports being a consultant for Medtronic. Dr Finn reports research grants from Medtronic; and being a consultant for Medtronic. D’Anne Kudlik, Dr Kirchhof, and Lexcen report employment by Medtronic. Dr Kassotis reports being a consultant for Medtronic., (Copyright © 2024 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Background: Transvenous lead extraction can have serious adverse events, such as cardiac or vascular perforation. Risk factors have not been well characterized., Objective: The purpose of this study was to identify factors associated with perforation and death, and to characterize lead extraction in a large contemporary population., Methods: We performed a retrospective multicenter study examining patients undergoing lead extraction at 8 Canadian institutions from 1996 through 2016. Demographic and clinical data were used to identify variables associated with perforation and mortality using logistic regression modeling., Results: A total of 2325 consecutive patients (age 61.9 ±16.5 years) underwent extraction of 4527 leads. Perforation rate was 2.7% (63/2325) and 30-day mortality was 1.6% (38/2325), with mortality of 0.4% due to perforation (10/2325). Variables associated with perforation included no previous cardiac surgery (odds ratio [OR] 3.33; 95% confidence interval [CI] 1.54-7.19; P = .002), female sex (OR 3.27; 95% CI 1.91-5.60; P <.001); left ventricular ejection fraction ≥40% (OR 2.81; 95% CI 1.28-6.14; P = .010); lead age >8 years (OR 2.64; 95% CI 1.52-4.60; P <.001); ≥2 leads extracted (OR 2.49; 95% CI 1.23-5.04; P = .011); and diabetes (OR 2.12; 95% CI 1.16-3.86; P = .014). Variables associated with death included infection as indication for extraction (OR 3.85; 95% CI 1.38-10.73; P = .010); anemia (OR 3.14; 95% CI 1.38-6.61; P = .003), and patient age (OR 1.04; 95% CI 1.01-1.07; P = .012)., Conclusion: Risk factors associated with perforation in lead extraction include no history of cardiac surgery, female sex, preserved left ventricular ejection fraction, lead age >8 years, ≥2 leads extracted, and diabetes., (Copyright © 2021. Published by Elsevier Inc.)

Background: Hematoma is a complication of cardiac implantable electronic device (CIED) procedures and may lead to device infection. The TYRX antibacterial envelope reduced major CIED infection by 40% in the randomized WRAP-IT (World-wide Randomized Antibiotic Envelope Infection Prevention Trial) study, but its effectiveness in the presence of hematoma is not well understood., Objective: The purpose of this study was to evaluate the incidence and infectious consequences of hematoma and the association between envelope use, hematomas, and major CIED infection among WRAP-IT patients., Methods: All 6800 study patients were included in this analysis (control 3429; envelope 3371). Hematomas occurring within 30 days postprocedure (acute) were characterized and grouped by study treatment and evaluated for subsequent infection risk. Data were analyzed using Cox proportional hazard regression modeling., Results: Acute hematoma incidence was 2.2% at 30 days, with no significant difference between treatment groups (envelope vs control hazard ratio [HR] 1.15; 95% confidence interval [CI] 0.84-1.58; P = .39). Through all follow-up, the risk of major infection was significantly higher among control patients with hematoma vs those without (13.1% vs 1.6%; HR 11.3; 95% CI 5.5-23.2; P <.001). The risk of major infection was significantly lower in the envelope vs control patients with hematoma (2.5% vs 13.1%; HR 0.18; 95% CI 0.04-0.85; P = .03)., Conclusion: The risk of hematoma was 2.2% among WRAP-IT patients. Among control patients, hematoma carried a >11-fold risk of developing a major CIED infection. This risk was significantly mitigated with antibacterial envelope use, with an 82% reduction in major CIED infection among envelope patients who developed hematoma compared to control., (Copyright © 2021 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Physicians engaged in cardiovascular implantable electronic device (CIED)-related practice come from diverse training backgrounds with variable degrees of CIED implant training. The objective of the Canadian Heart Rhythm Society Task Force on CIED Implant Training was to establish a common structure and content for training programs in CIED implantation, related activities and maintenance of competency. This executive summary presents the essence of the report with key recommendations included, with the complete version made available in a linked supplement. The goals are to ensure that future generations of CIED implanters are better prepared for continuously evolving CIED practice and quality care for all Canadians., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)

Aim: The Prevention of Arrhythmia Device Infection Trial (PADIT) infection risk score, developed based on a large prospectively collected data set, identified five independent predictors of cardiac implantable electronic device (CIED) infection. We performed an independent validation of the risk score in a data set extracted from U.S. healthcare claims., Methods and Results: Retrospective identification of index CIED procedures among patients aged ≥18 years with at least one record of a CIED procedure between January 2011 and September 2014 in a U.S health claims database. PADIT risk factors and major CIED infections (with system removal, invasive procedure without system removal, or infection-attributable death) were identified through diagnosis and procedure codes. The data set was randomized by PADIT score into Data Set A (60%) and Data Set B (40%). A frailty model allowing multiple procedures per patient was fit using Data Set A, with PADIT score as the only predictor, excluding patients with prior CIED infection. A data set of 54 042 index procedures among 51 623 patients with 574 infections was extracted. Among patients with no history of prior CIED infection, a 1 unit increase in the PADIT score was associated with a relative 28% increase in infection risk. Prior CIED infection was associated with significant incremental predictive value (HR 5.66, P < 0.0001) after adjusting for PADIT score. A Harrell's C-statistic for the PADIT score and history of prior CIED infection was 0.76., Conclusion: The PADIT risk score predicts increased CIED infection risk, identifying higher risk patients that could potentially benefit from targeted interventions to reduce the risk of CIED infection. Prior CIED infection confers incremental predictive value to the PADIT score., (© The Author(s) 2021. Published by Oxford University Press on behalf of the European Society of Cardiology.)

Aims: Cardiac implantable electronic devices with device advisories have the potential of device malfunction. Remote monitoring (RM) of devices has been suggested to allow the identification of abnormal device performance and permit early intervention. We sought to describe the outcomes of patients with and without RM in devices subject to the Abbott Premature Battery Depletion (PBD) advisory with data from a Canadian registry., Methods and Results: Patients with an Abbott device subject to the PBD advisory from nine implantable cardioverter defibrillator (ICD) implanting centres in Canada were included in the registry. The use of RM was identified from baseline and follow-up data in the registry. The primary outcome was detection of PBD and all-cause mortality. A total of 2666 patients were identified with a device subject to the advisory. In all, 1687 patients (63.2%) had RM at baseline. There were 487 deaths during follow-up. At a mean follow-up of 5.7 ± 0.7 years, mortality was higher in those without a remote monitor compared with RM at baseline (24.7% vs. 14.5%; P < 0.001). Pre-mature battery depletion was identified in 36 patients (2.1%) with RM vs. 7 (0.7%) without RM (P = 0.004). Time to battery replacement was significantly reduced in patients on RM (median 5 vs. 13 days, P = 0.001)., Conclusion: The use of RM in patients with ICD and cardiac resynchronization therapy under advisory improved detection of PBD, time to device replacement, and was associated with a reduction in all-cause mortality. The factors influencing the association with mortality are unknown and deserve further study., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2021. For permissions, please email: journals.permissions@oup.com.)

Background: Cardiac device procedures require tissue dissection to free existing device lead(s). Common techniques include blunt dissection, standard electrocautery, and low-temperature electrocautery (PlasmaBlade, Medtronic); however, data on the type of electrosurgical tool used and the development of procedure- or lead-related adverse events are limited., Objective: The purpose of this study was to determine whether standard or low-temperature electrocautery impacts the development of an adverse event., Methods: We evaluated patients enrolled in WRAP-IT (Worldwide Randomized Antibiotic EnveloPe Infection PrevenTion Trial) undergoing cardiac implantable electronic device (CIED) revision, upgrade, or replacement. All adverse events were adjudicated by an independent physician committee. Data were analyzed using Cox proportional hazard regression modeling., Results: In total, 5641 patients underwent device revision/upgrade/replacement. Electrocautery was used in 5205 patients (92.3%) (mean age 70.6 ± 12.7 years; 28.8% female), and low-temperature electrocautery was used in 1866 patients (35.9%). Compared to standard electrocautery, low-temperature electrocautery was associated with a 23% reduction in the incidence of a procedure- or lead-related adverse event through 3 years of follow up (hazard ratio [HR] 0.77; 95% confidence interval [CI] 0.65-0.91; P = .002). After controlling for the number of active leads, degree of capsulectomy, degree of lead dissection, and renal dysfunction, low-temperature electrocautery was associated with a 32% lower risk of lead-related adverse events (HR 0.68; 95% CI 0.52-0.89; P = .004). These effects were consistent across a spectrum of lead-related adverse event types., Conclusion: This study represents one of the largest assessments of electrocautery use in patients undergoing CIED revision, upgrade, or replacement procedures. Compared to standard electrocautery, low-temperature electrocautery significantly reduces adverse effects from these procedures., (Copyright © 2021 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Background: Cardiac implantable electrical devices (CIEDs) are subject to advisories and complications that can result in morbidity and mortality for patients; there is currently no system in Canada to track these., Methods: This was a multicenter, prospective cohort study conducted at 5 centers to determine feasibility. Patients with a de novo high-voltage (HV) lead implantation were included and followed for a minimum of 1 year., Results: There were 611 leads enrolled into the registry over 18 months. The mean age was 62.4 ± 12.8 years; 144 (23.6%) women were enrolled. The indication for lead implantation was for primary prevention in 65.5%. There were 497 (82.1%) de novo devices (single chamber: 54.5%, dual chamber: 20.5%, cardiac resynchronization therapy [CRT] 25.0%); the remainder of the procedures was a system revision for either upgrade (8.1%) or lead revision (9.8%). The lead revision rate at 1 year was 3.4%, with the primary reason being lead dislodgements. Mortality rate was 3.8% at 1 year. The rate of any device-related complication was 2.0% at 30 days, with the highest rate in CRT implants (4.9%, P = 0.0105). At 1 year, the complication rate was 4.5%, with no significant difference among device types., Conclusions: This study demonstrates that device surveillance is feasible and highlights (1) the need for CIED surveillance to track device-related complications, (2) the scope of this should be larger, and (3) mandatory participation should be considered. This system could predict CIEDs that may be susceptible to higher than usual rates of failure, mitigating adverse outcomes in patients., (Copyright © 2018 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.)

Background: The Riata lead advisory was announced in 2011 and has posed unique management challenges because of cable externalization and insulation abrasion, in some cases leading to sudden loss of defibrillation., Objective: The purpose of this study was to provide further data on the rate of electrical failure in a population of patients with a Riata lead under advisory., Methods: Using the Canadian Registry of Electronic Device Outcomes, prospective follow-up data were collected on 1352 Riata leads under advisory in 17 implantable cardioverter-defibrillator (ICD) implantation centers in Canada. Data on electrical and structural failure were collected, as well as periprocedural complications related to lead revision (abandonment or extraction)., Results: Of the 1352 leads included in this 12-month follow-up cohort, 110 leads were revised. Mean follow-up time was 10.4 ± 1.5 years. The 12-year rate of electrical failure for the 8Fr lead was 9.45%, whereas the 10-year failure rate for the 7Fr lead was 7.25% and was not found to be accelerating. Of the leads revised because of advisory only (patient preference, advisory related, electrical or structural failure), the majority were abandoned (n = 54 [76.0%]), whereas 17 (24.0%) were extracted using power tools. The rate of major complications in each group was 5.6% and 5.9%, respectively., Conclusion: This report provides further data on the risk of electrical lead failure over a long lead dwell time. The risk of failure exceeds the risk of periprocedural major complications, indicating that the risk-to-benefit ratio is favorable to revise the lead in appropriate clinical scenarios., (Copyright © 2017 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Background: The Riata lead under advisory has posed a unique clinical scenario where inside-out abrasion results in externalization of conductor cables, with a higher risk of electrical failure. We developed a comprehensive registry to assist with clinical management of this lead., Methods and Results: This Canadian registry reports the findings of 3763 (74.2% of all Riata leads in Canada) Riata leads under advisory, with a mean follow-up time of 8.9±1.5 years. The overall electrical failure rate was 5.2% at 8 years, with no difference between 7-French and 8-French lead models. Cable externalization was found to be more common in the 8-French model (12.3% versus 5.2%, P<0.0001) and was associated with a higher risk of electrical failure. Predictors of electrical lead failure included cable externalization, higher left ventricular ejection fraction, younger age, higher body mass index, and a passive fixation lead. One patient died due to electrical failure, a further 2 patients survived an event where the device failed to deliver high-voltage therapy. Major complications because of lead extraction were higher when compared with lead abandonment, no difference among lead model observed. Two deaths occurred as a consequence of lead extraction, in the context of an underlying infection., Conclusions: The Riata lead under advisory has a steady electrical failure rate over time. There are identifiable predictors of lead failure that can assist with clinical decisions as to whether lead revision should be performed prophylactically., (© 2016 American Heart Association, Inc.)

Background: Patients who require perioperative anticoagulation during cardiac implantable electronic device surgery are at increased risk for bleeding complications. The BRUISE CONTROL trial demonstrated that continuing warfarin was safer than heparin bridging, reducing the incidence of clinically significant pocket hematoma. Novel oral anticoagulants are being increasingly prescribed in place of warfarin. The best perioperative management of these new anticoagulants is unknown., Methods/design: A randomized controlled trial to investigate whether a strategy of continued vs interrupted novel oral anticoagulant (dabigatran, rivaroxaban, or apixaban) at the time of device surgery, in patients with moderate to high risk of arterial thromboembolic events, reduces the incidence of clinically significant hematoma (defined as a hematoma requiring reoperation and/or resulting in prolongation of hospitalization, and/or requiring interruption of anticoagulation). The secondary outcomes include components of the primary outcome, composite of all other major perioperative bleeding events, thromboembolic events, all-cause mortality, cost-effectiveness, patient quality of life, perioperative pain, and satisfaction. Planned analyses include descriptive statistics of all baseline variables. For the primary outcome, interrupted vs continued novel oral anticoagulant arms will be compared using the χ(2) test. If any clinically significant differences are identified, a logistic regression analysis will be conducted. Quality of life will be assessed using EuroQol-5D, and perioperative pain using a visual analog scale., Discussion: BRUISE CONTROL-2 is a randomized trial evaluating the best strategy to manage novel oral anticoagulants at the time of device surgery. We hypothesize that device surgery can be performed safely without interruption of these medications., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Magnetic resonance imaging (MRI) has historically been considered contraindicated for individuals with cardiac implantable electronic devices (CIEDs) such as pacemakers and implantable defibrillators. Magnetic resonance scanners produce magnetic fields that can interact negatively with the metallic components of CIEDs. However, as CIED technology has advanced, newer MRI conditional devices have been developed that are now in clinical use and these systems have had demonstrated safety in the MRI environment. Despite the supportive data of such CIED systems, physicians remain reluctant to perform MRI scanning of conditional devices. This joint statement by the Canadian Heart Rhythm Society and the Canadian Association of Radiologists describes a collaborative process by which CIED specialists and clinics can work with radiology departments and specialists to safely perform MRI in patients with MRI conditional CIED systems. The steps required for patient and scanning preparation and the roles and responsibilities of the CIED and radiology departments are outlined. We also briefly outline the risks and a process by which patients with nonconditional CIEDs might also receive MRI in highly specialized centres. This document supports MRI in patients with MRI conditional CIEDs and offers recommendations on how this can be implemented safely and effectively., (Copyright © 2014. Published by Elsevier Inc.)

Magnetic resonance imaging (MRI) has historically been considered contraindicated for individuals with cardiac implantable electronic devices (CIEDs) such as pacemakers and implantable defibrillators. Magnetic resonance scanners produce magnetic fields that can interact negatively with the metallic components of CIEDs. However, as CIED technology has advanced, newer MRI conditional devices have been developed that are now in clinical use and these systems have had demonstrated safety in the MRI environment. Despite the supportive data of such CIED systems, physicians remain reluctant to perform MRI scanning of conditional devices. This joint statement by the Canadian Heart Rhythm Society and the Canadian Association of Radiologists describes a collaborative process by which CIED specialists and clinics can work with radiology departments and specialists to safely perform MRI in patients with MRI conditional CIED systems. The steps required for patient and scanning preparation and the roles and responsibilities of the CIED and radiology departments are outlined. We also briefly outline the risks and a process by which patients with nonconditional CIEDs might also receive MRI in highly specialized centres. This document supports MRI in patients with MRI conditional CIEDs and offers recommendations on how this can be implemented safely and effectively., (Copyright © 2014 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.)

Background: The St. Jude Medical Riata family of implantable cardioverter-defibrillator (ICD) leads has demonstrated a high rate of externalized conductors and electrical failure., Objective: Given similar design elements of Durata to Riata, the purpose of this study was to assess the rates of failure of the Riata ST Optim and Durata lead families in Canada., Methods: All Canadian ICD-implanting centers were invited to submit follow-up information on all Optim-coated ICD leads implanted. Electrical failure was defined as a rapid change in impedance or pacing capture threshold leading to lead revision, or oversensing due to noise. Externalized conductors were defined as appearance of conductor wires outside the lead body. Systematic fluoroscopic screening for externalized conductors was not performed., Results: As of December 1, 2012, 15 of 25 centers provided data on 3981 leads (44% of those sold in Canada during the same timeframe): 3477 Durata and 504 Riata ST Optim leads. The most common model numbers were 7122 (1516 leads [38%]), 7121 (707 leads [18%]), and 7120 (622 leads [16%]). Mean follow-up duration from implant to December 1, 2012, was 4.47 ± 0.48 years for Riata ST Optim leads and 2.00 ± 1.10 years for Durata leads. The annual rate of lead failure was 0.27% per year for Riata ST Optim leads and 0.24% per year for Durata leads. No instances of externalized conductors were identified in the failed leads. No deaths were attributed to lead failure; however, 2 patients experienced inappropriate shocks due to lead failure., Conclusion: The overall electrical failure rates of the Riata ST Optim and Durata leads appear to be low, and no instances of externalized conductors were observed., (© 2013 Heart Rhythm Society. All rights reserved.)

Randomized clinical trials are a major advance in clinical research methodology. However, there are myriad important questions about the effectiveness of treatments used in daily practice that are not informed by the results of randomized trials. This is in part because of important limitations inherent in the methodology of randomized efficacy trials which are performed with tight control of inclusion, exclusion, treatment, and follow-up. This approach enhances evaluation of clinical efficacy (performance in controlled situations) but increases complexity and is not well suited to test clinical effectiveness (performance under conditions of actual use). The cluster crossover trial is a new concept for efficient comparative effectiveness testing. Deep tissue infection occurs in 2% of patients after arrhythmia device implantation, usually requires system extraction, and increases mortality. There is variation in antibiotic prophylaxis used to reduce implanted device infections. To efficiently evaluate the comparative effectiveness of antibiotic strategies now in use, we designed a cluster crossover clinical trial, which randomized implanting centres to 1 of 2 prophylactic antibiotic strategies, which became the standard care at the centre for 6 months, followed by crossover to the other strategy, rerandomization, and second crossover. This method greatly reduces trial complexity because it aligns study procedures with usual clinical care and increases generalizability. Pilot studies have tested the feasibility and an 10,800-patient trial, funded by the Canadian Institutes of Health Research, is now under way. The cluster crossover randomized trial design is well suited to efficiently test comparative effectiveness of existing treatments where there is variability of practice, clinical equipoise, and minimal risk., (Copyright © 2013 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.)

Remote monitoring (RM) is a form of telemedicine technology that permits implanted pacemakers and implantable cardioverter-defibrillators to transmit diagnostic information for review by health care professionals without patients needing to visit the device follow-up clinic. A bedside transmitter in the patient's home conveys the device data using standard telecommunication protocol to a protected internet-accessible RM data server, which authorized health care professionals can access at any time using standard web browser software. Evidence indicates it can accelerate identification of clinical events and potential device problems. RM raises important medicolegal issues concerning the protection of a patient's rights and the safeguarding of patient health information related to the collection, storage, and use of patient device information that must be addressed by follow-up centres. This position statement recommends that remote monitoring be available at all device follow-up clinics as an integral part of the standard of care of device patients and also provides helpful advice to centres for the proper design, implementation, and integration of a remote monitoring system into the clinic., (Copyright © 2013. Published by Elsevier Inc.)

Background: A unique form of lead failure has been described in the Riata (8-F) and Riata ST (7-F) silicone defibrillation lead degradation of the outer insulation, resulting in the externalization of conductor cables., Objective: To assess rates of lead revision due to lead failure in Riata leads affected by the Riata advisory., Methods: Nineteen implantable cardioverter-defibrillator implant and follow-up centers were surveyed., Results: As of March 1, 2012, there were 5043 known affected leads implanted in Canada. Data on 4358 (86.4%) leads were obtained; 65.3% of these were Riata (8-F) and 32.4% were Riata ST (7-F) leads. The median time from implant to last follow-up was 5 years. Electrical abnormalities were reported in 4.6% of the affected leads; 8.0% of these were found to have concomitant radiographic evidence of externalization. The rate of electrical failure was higher in the 8-F (5.2%) vs 7-F (3.3%) leads (P = .007). Oversensing with or without inappropriate shocks was reported in 39.8% of the leads with confirmed failure. Abnormally high or low impedance values (29.9%) and elevated pacing capture thresholds (43.8%) were frequently reported. One death (0.5%) attributed to lead failure was reported. Among the leads that were replaced, 21% were extracted. Two major complications (1.0%) were attributed to extraction of these leads., Conclusions: The overall rate of lead failure in the Riata (8-F) and Riata ST (7-F) leads is higher than previously reported by using passive surveillance data. The impact of recent advisories related to these leads is not yet apparent., (Copyright © 2013 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Introduction: The need to perform defibrillation testing (DT) at the time of implantable cardioverter defibrillator (ICD) insertion is controversial. In the absence of randomized trials, some regions now perform more than half of ICD implants without DT., Methods: During the last year of enrolment in the Resynchronization for Ambulatory Heart Failure Trial, a substudy randomized patients to ICD implantation with versus without DT., Results: Among 252 patients screened, 145 were enrolled; 75 randomized to DT and 70 to no DT. Patients were similar in terms of age (65.9 ± 9.3 years vs 67.9 ± 8.9 years); LVEF (24.7 ± 4.6% vs 23.6 ± 4.6%), QRS width (154.8 ± 23.5 vs 155.8 ± 23.6 ms), and history of atrial fibrillation (5% vs 6%). All 68 patients in the DT arm tested according to the protocol achieved a successful DT (≤25 J); 96% without requiring any system modification. No patient experienced perioperative stroke, myocardial infarction, heart failure (HF), intubation or unplanned ICU stay. The length of hospital stay was not prolonged in the DT group: 20.2 ± 26.3 hours versus 21.3 ± 23.0 hours, P = 0.79. One patient in the DT arm had a failed appropriate shock and no patient suffered an arrhythmic death. The composite of HF hospitalization or all-cause mortality occurred in 10% of patients in the no-DT arm and 19% of patients in the DT arm (HR = 0.53, 95% CI: 0.21-1.31, P = 0.14)., Conclusions: In this randomized trial, perioperative complications, failed appropriate shocks, and arrhythmic death were all uncommon regardless of DT. There was a nonsignificant increase in the risk of death or HF hospitalization with DT., (© 2012 Wiley Periodicals, Inc.)

Background: There is uncertainty about the proper role of defibrillation testing (DT) at the time of implantable cardioverter defibrillator (ICD) insertion., Methods: A prospective registry was conducted at 13 sites in Canada between January 2006 and October 2007., Objectives: To document the details of DT, the reasons for not conducting DT, and the costs and complications associated with DT., Results: DT was conducted at implantation in 230 of 361 patients (64%). DT was more likely to be conducted for new implants compared with impulse generator replacements (71% vs 32%, P = 0.0001), but was similar for primary and secondary prevention indications (64% vs 63%, P = NS). Among patients not having DT, the reason(s) given were: considered unnecessary (44%); considered unsafe, mainly due to persistent atrial fibrillation (37%); lack of an anesthetist (20%); and, patient or physician preference (6%). When performed, DT consisted of a single successful shock > or = 10J below maximum device output in 65% of cases. A 10J safety-margin was met by 97% of patients, requiring system modification in 2.3%. Major perioperative complications occurred in 4.4% of patients having DT versus 6.6% of patients not having DT (P = NS). ICD insertion was $844 more expensive for patients having DT (P = 0.16), largely due to increased costs ($28,017 vs $24,545) among patients having impulse generator replacement (P = 0.02)., Conclusions: DT was not performed in a third of ICD implants, usually due to a perceived lack of need or relative contraindication.

Background: The effect of cardiac resynchronization therapy (CRT) on physical function and Quality of Life (QoL) in patients who require an implantable defibrillator but do not meet guideline criteria for CRT has not been studied in detail., Methods and Results: This was a randomized study of 72 patients with high risk of sudden cardiac death, ejection fraction (EF) < or =35%, mild-to-moderate heart failure symptoms, and QRS > 120 ms. Patients received a CRT defibrillator and were randomized to CRT turned ON or OFF. Objective and subjective measures were performed at baseline and after 6 months. There was no difference in change in left ventricular end-systolic volume (ESV) by radionuclid angiogram scan, the primary endpoint, between the CRT ON group (DeltaESV =-7 +/- 52 mL), and CRT OFF group (DeltaESV =-30 +/- 47 mL). Similarly, echocardiogram measures of ESV and EF showed no difference between the two groups. In the CRT ON group, selected measures of QoL and subjective exercise tolerance but not heart failure symptoms improved significantly. Six-minute walk distance prolonged in the CRT ON group (baseline 313.6 +/- 114.4 m, 6-month 365.0 +/- 122.5 m, P = 0.01), but the difference in change in walk distance between the two groups was not significant., Conclusion: Further studies with larger sample size and longer follow-up will be required to allow definite conclusions regarding the potential benefit of CRT in this patient population.

Background: Defibrillation threshold (DFT) testing has traditionally been a routine part of implantable cardioverter-defibrillator (ICD) implantation, despite a lack of compelling evidence that it predicts or improves outcomes. In the past, when devices were much less reliable, DFT testing seemed prudent; however, modern ICD systems have such a high rate of successful defibrillation that many electrophysiologists now question whether DFT testing is still worthwhile, particularly since DFT testing may now be the highest acute risk component of ICD implantation., Objective: The purpose of this study was to systematically document complications directly attributable to intraoperative DFT testing., Methods: We obtained data on DFT-related complications from all 21 adult ICD implant centers in Canada, covering the period from January 1, 2000, to September 30, 2006., Results: There were a total of 19,067 ICD implants in Canada during the study period. There were three DFT testing-related deaths, five DFT testing-related strokes, and 27 episodes that required prolonged resuscitation. Two patients had significant clinical sequelae after prolonged resuscitation., Conclusions: The risk of severe complications from intraoperative DFT testing appears small, even allowing for the underestimation of its true rate with the current study methodology. These slight but measurable risks must be considered when assessing the risk-benefit ratio of the procedure. Additional data from ongoing prospective ICD registries and/or clinical trials are required.