Increased incidence of electrical abnormalities in a pacemaker lead family.

INTRODUCTION: Several recent studies have raised concern about noise detections on Tendril pacemaker leads, which may represent insulation failure or algorithm-driven overreporting of physiologic signals. METHODS: We identified all pacemaker leads actively followed at Albany Medical Center, of which 1111 leads (262 Abbott Tendril, 576 Medtronic CapSure, 30 Fineline, 195 Ingevity, 48 Dextrus) in 703 patients were included in this observational study. Electrical abnormalities, comprising low-impedance measurements <200 Ω and repeated noise detections, were catalogued, as was initial management and subsequent need for surgical intervention. RESULTS: During 54 months median follow-up (interquartile range 24-105), 63 leads (5.7%) demonstrated electrical abnormalities, including low impedances in 21 and noise in 59. Tendril leads manifested abnormalities most frequently (n = 50; 19.1%) compared with CapSure (n = 9; 1.6%), Fineline (n = 0), Ingevity (n = 0), and Dextrus (n = 4; 8.3%) leads. The risk of abnormalities was significantly higher in Tendril leads (HR 9.6, 95% CI 5.2-17.6; p < .001). Low impedances were measured on 19 Tendril leads, a significantly higher risk than on other leads (HR 23.8, 95% CI 5.5-102.1; p < .001). Although observation and reprogramming sensitivity were the initial management strategy for 45 and 7 leads, respectively, 18 ultimately required surgical intervention, including 15 Tendrils. No electrical abnormalities were observed in 12 non-Tendril leads attached to Abbott devices compared with 48 of 252 Tendrils attached to Abbott devices (log-rank p = .035). CONCLUSION: Tendril leads demonstrate significantly higher risk of repeated low impedances and noise compared to other manufacturers' models, raising concern that these findings reflect early insulation failure. Increased scrutiny is warranted.

Severe chronic kidney disease is associated with poor survival after initial CRT-defibrillator tachyarrhythmia therapy.

BACKGROUND: Implantable cardioverter-defibrillator (ICD) recipients who receive appropriate device therapies have limited survival, and survival benefit in chronic kidney disease (CKD) has been questioned. We examined the association between CKD and survival after cardiac resynchronization therapy (CRT)-defibrillator tachyarrhythmia therapies. METHODS: We compared overall survival after appropriate shocks or anti-tachycardia pacing in 439 CRT-defibrillator recipients with left ventricular ejection fraction (LVEF) ≤35%, non-right bundle-branch block QRS pattern, and QRS duration >130 ms according to glomerular filtration rate (GFR) at implant, including 31 patients with GFR ≤30, 164 patients with GFR 31-60, and 244 patients with GFR >60. At least one shock occurred in 302 patients (24 with GFR ≤30, 102 with GFR 31-60, and 176 with GFR >60). Serial echocardiograms were also compared. RESULTS: Patients were followed 64 months (interquartile range [IQR]: 29-94) after implant, including 32 months (IQR: 12-61) after first therapy. Time to first therapy or shock was similar across GFR groups. However, survival after first therapy declined directly with declining GFR (P < .001), with median postshock survival of 90 days for GFR ≤30 (95% confidence of interval [CI]: 0-233), 612 days (95% CI: 365-859) for GFR 31-60, and 1672 days (95% CI: 1396-1948) for GFR >60. Declining GFR category, ischemic heart disease, diabetes, and increasing age were independently associated with increased postshock mortality. Echocardiographic response was similar across GFR groups and was not associated with post-therapy survival. CONCLUSIONS: Survival after appropriate tachyarrhythmia therapies, particularly shocks, is attenuated in patients with GFR ≤30. This raises concern over potential lack of survival benefit conferred by CRT-defibrillators versus CRT-pacemakers in this population.

Amiodarone is associated with adverse outcomes in patients with sustained ventricular arrhythmias upgraded to cardiac resynchronization therapy-defibrillators.

INTRODUCTION: Amiodarone reduces recurrent ventricular tachyarrhythmias (VTA) but may worsen cardiovascular outcomes in heart failure (HF) patients. Cardiac resynchronization therapy (CRT) may also be antiarrhythmic. When patients with prior sustained VTA are upgraded to CRT defibrillators (CRT-D) from conventional implantable cardioverter-defibrillators (ICDs), should concomitant amiodarone be continued or is CRT's antiarrhythmic potential sufficient? METHODS AND RESULTS: We identified 67 patients from a prospective CRT registry with spontaneous sustained VTA, New York Heart Association (NYHA) II-IV HF, and left bundle-branch block (LBBB) who were upgraded to CRT defibrillators from conventional ICDs. We compared changes in QRS duration and left ventricular ejection fraction (LVEF) pre- and post-CRT, time to death, transplant or ventricular assist device (VAD), and time to recurrent VTA therapies between 37 patients continuing amiodarone therapy and 30 amiodarone-naïve patients. Amiodarone-treated patients had worse renal function and a higher prevalence of prior VTA storm compared with amiodarone-naïve patients. After CRT, amiodarone-treated patients demonstrated less QRS narrowing (8 vs 20 ms; P = 0.021) and less LVEF improvement (-2.7 vs +5.2%; P = 0.006). Over 29 months, 31 (47%) patients died and 13 (20%) received transplant or VAD. Risk of death, transplant, or VAD was greater in amiodarone-treated than -naïve patients (corrected hazard ratio [HR], 2.14; 95% confidence interval [CI], 1.12-4.11; P = 0.022). Appropriate CRT-D therapies occurred in 37 (55%) patients; amiodarone use was not associated time to first therapy (HR, 1.13; 95% CI, 0.59-2.16; P = 0.72). CONCLUSION: In patients with sustained VTA and LBBB upgraded from conventional ICDs to CRT defibrillators, concomitant amiodarone use is associated with less QRS narrowing, less LVEF improvement, greater risk of death, transplant, or VAD, and similar risk of recurrent VTA.

Oral Anticoagulation for Atrial Fibrillation Thromboembolism Prophylaxis in the Chronic Kidney Disease Population: the State of the Art in 2019.

Atrial fibrillation (AF) is the most common cardiac rhythm disturbance and is associated with increased risk of thromboembolism. Oral anticoagulants are effective at reducing rates of thromboembolism in patients with AF in the general population. Patients with AF and concurrent chronic kidney disease (CKD) have higher risk of thromboembolism and bleeding compared with patients with normal renal function. Among moderate CKD and end-stage renal disease (ESRD) patients on chronic dialysis, the use of oral anticoagulants is controversial. Use of warfarin, while beneficial in non-CKD patients, raises a number of concerns such as increased bleeding risk, labile anticoagulant effect, and calciphylaxis, especially in the ESRD population. The newer direct oral anticoagulant (DOAC) agents have demonstrated comparable efficacy and improved safety profiles compared with coumadin but are not as well studied in the CKD population. This review highlights the efficacy and safety of coumadin and the DOACs for thromboembolism prophylaxis in non-valvular AF patients with CKD.

Sex-specific clinical outcomes after cardiac resynchronization therapy in left bundle branch block-associated idiopathic nonischemic cardiomyopathy: A NEOLITH II substudy.

BACKGROUND: Sex differences in clinical outcomes for left bundle branch block (LBBB)-associated idiopathic nonischemic cardiomyopathy (NICM) after cardiac resynchronization therapy (CRT) are not well described. METHODS: A retrospective cohort study at an academic medical center included subjects with LBBB-associated idiopathic NICM who received CRT. Cox regression analyses estimated the hazard ratios (HRs) between sex and clinical outcomes. RESULTS: In 123 total subjects (mean age 62 years, mean initial left ventricular ejection fraction 22.8%, 76% New York Heart Association class III, and 98% CRT-defibrillators), 55 (45%) were men and 68 (55%) were women. The median follow-up time after CRT was 72.4 months. Similar risk for adverse clinical events (heart failure hospitalization, appropriate implantable cardioverter-defibrillator shock, appropriate antitachycardia pacing therapy, ventricular assist device implantation, heart transplantation, and death) was observed between men and women (HR, 1.20; 95% confidence interval [CI] 0.57-2.51; p = 0.63). This persisted in multivariable analyses. Men and women had similar risk for all-cause mortality in univariable analysis, but men had higher risk in the final multivariable model that adjusted for age at diagnosis, QRS duration, and left ventricular end-diastolic dimension index (HR, 4.55; 95% CI, 1.26-16.39; p = 0.02). The estimated 5-year mortality was 9.5% for men and 6.9% for women. CONCLUSIONS: In LBBB-associated idiopathic NICM, men have higher risk for all-cause mortality after CRT when compared to women.

Myocardial recovery after cardiac resynchronization therapy in left bundle branch block-associated idiopathic nonischemic cardiomyopathy: A NEOLITH II substudy.

BACKGROUND: Baseline predictors of myocardial recovery after cardiac resynchronization therapy (CRT) in left bundle branch block (LBBB)-associated idiopathic nonischemic cardiomyopathy (NICM) are unknown. METHODS: A retrospective study included subjects with idiopathic NICM, left ventricular ejection fraction (LVEF) ≤35%, and LBBB. Myocardial recovery was defined as post-CRT LVEF ≥50%. Logistic regression analyses described associations between baseline characteristics and myocardial recovery. Cox regression analyses estimated the hazard ratio (HR) between myocardial recovery status and adverse clinical events. RESULTS: In 105 subjects (mean age 61 years, 44% male, mean initial LVEF 22.6% ± 6.6%, 81% New York Heart Association class III, and 98% CRT-defibrillators), myocardial recovery after CRT was observed in 56 (54%) subjects. Hypertension, heart rate, and serum blood urea nitrogen (BUN) had negative associations with myocardial recovery in univariable analyses. These associations persisted in multivariable analysis: hypertension (odds ratio (OR), 0.40; 95% confidence interval (CI), 0.17-0.95; p = 0.04), heart rate (OR per 10 bpm, 0.69; 95% CI, 0.48-0.997; p = 0.048), and serum BUN (OR per 1 mg/dl, 0.94; 95% CI, 0.88-0.99; p = 0.04). Subjects with post-CRT LVEF ≥50%, when compared to <50%, had lower risk for adverse clinical events (heart failure hospitalization, appropriate implantable cardioverter-defibrillator shock, appropriate anti-tachycardia pacing therapy, ventricular assist device implantation, heart transplantation, and death) over a median follow-up of 75.9 months (HR, 0.38; 95% CI, 0.16-0.88; p = 0.02). CONCLUSION: In LBBB-associated idiopathic NICM, myocardial recovery after CRT was associated with absence of hypertension, lower heart rate, and lower serum BUN. Those with myocardial recovery had fewer adverse clinical events.

Characterization of pulmonary vein reconnection post Cryoballoon ablation.

BACKGROUND: The Arctic Front Cryoballoon System is a technology in which substrate alterations in patients with atrial fibrillation (AF) recurrence have not been well characterized. In this study, we evaluated sites of pulmonary vein (PV) reconnections and the accuracy of the Achieve™ circular mapping catheter in detecting these reconnections after cryoablation. METHODS: This study included 15 patients undergoing redo AF ablation after a prior single cryoablation procedure. PV reconnection sites were determined by measuring PV signals and high output pacing from 4 vectors of the Achieve catheter. The results were compared with a roving mapping catheter guided by rotational intracardiac echocardiography (ICE) in the left atrium. RESULTS: All patients had PV reconnections (2.1 ±â€¯0.8 veins/patient). The left superior PV was most commonly reconnected (n = 11), whereas the right inferior PV was least likely (n = 3). Both carinas (left: n = 11; right: n = 7) and left atrial appendage ridge (n = 11) were also frequently reconnected. Mapping with the Achieve catheter showed a positive predictive value (PPV) 100% and negative predictive value (NPV) 96% when compared with ICE guided mapping. In 2 patients, right superior PV reconnection was not identified by the Achieve. CONCLUSION: During redo AF ablation after index cryoablation, multiple PVs are usually reconnected, with both carinas and left atrial appendage ridge being common sites of reconnection. The Achieve mapping catheter was able to identify reconnection with high positive and negative predictive values.

Implantable cardioverter-defibrillator therapy in device recipients who survived a cardiac arrest associated with a reversible cause.

BACKGROUND: Guideline recommendations for implantable cardioverter-defibrillators (ICD) for secondary prevention of sudden cardiac arrest (SCA) have excluded patients with reversible causes. We previously demonstrated mortality benefit with the ICD in survivors of SCA associated with reversible causes other than myocardial infarction (MI) or ischemia treated with coronary revascularization. In the current study, we examined the incidence of ICD therapy in patients with SCA related to reversible causes. METHODS: Data were collected for all patients over the age of 18 years who had survived to hospital discharge after SCA between 2002 and 2012. ICD recipients with reversible causes were divided into 2 groups based on their reversible etiology of SCA: MI + ICD (n = 132) and non-MI + ICD (n = 75). Delivered ICD therapy was examined. RESULTS: Over a follow-up period of 3.8 ± 3.1 years, more patients without MI/ischemia who received an ICD experienced appropriate (adjusted HR, 3.96; 95% CI, 1.32-11.84) but not inappropriate (adjusted HR, 0.65; 95% CI, 0.14-2.97) ICD therapy compared with patients without MI/ischemia. The proportion of patients receiving appropriate (P = 0.012) but not inappropriate (P = 0.80) ICD therapy was also higher in the non-MI + ICD compared with the MI + ICD group. CONCLUSION: We show higher rates of appropriate ICD therapy in survivors of SCA associated with reversible causes other than MI/ischemia. This finding, in conjunction with the previously demonstrated lower all-cause mortality noted in the presence of an ICD in SCA survivors with reversible etiology other than MI/ischemia, further supports consideration of ICD implantation in this population.

Oral anticoagulation and left atrial thrombi resolution in nonrheumatic atrial fibrillation or flutter: A systematic review and meta-analysis.

BACKGROUND: Oral anticoagulation (OAC) is prescribed for left atrial thrombi (LAT) in nonrheumatic atrial fibrillation (AF) and/or atrial flutter (AFL). The study objective was to review the existing evidence regarding LAT resolution in nonrheumatic AF and/or AFL with OAC agents. METHODS: Data sources included PubMed, EMBASE, and Cochrane Central Register of Controlled Trials (CENTRAL) between January 1, 1991 and February 10, 2017. English-language studies that assessed LAT resolution with OAC agents in subjects with nonrheumatic AF and/or AFL, by serial transesophageal echocardiography, and with follow-up times ≥ 3 weeks and < 1 year, were selected. Study quality was assessed using recommendations adapted from the Agency for Healthcare Research and Quality. Pooled LAT resolution rates were evaluated for vitamin K antagonist (VKA) studies and low risk of bias warfarin studies. RESULTS: The pooled LAT resolution rate of 619 subjects from 16 VKA studies was 63.7% (95% confidence interval [CI], 53.3%-72.9%). The pooled LAT resolution rate of 94 subjects from four studies that specified warfarin use, exclusion of prior long-term therapeutic OAC, and target international normalized ratio (INR) ≥ 2.0 and/or average achieved INR ≥ 2.0 was 79.3% (95% CI, 69.8%-86.4%). Two studies in direct-acting oral anticoagulants (DOACs) reported LAT resolution rates of 89.5% (17 of 19) for dabigatran and 41.5% (22 of 53) for rivaroxaban. CONCLUSIONS: Warfarin is the most studied initial OAC agent for treating LAT in nonrheumatic AF and/or AFL with a resolution rate of nearly 80%. Further studies in DOACs are warranted.

New-onset left bundle branch block-associated idiopathic nonischemic cardiomyopathy and time from diagnosis to cardiac resynchronization therapy: The NEOLITH II study.

BACKGROUND: The optimal timing for cardiac resynchronization therapy (CRT) after diagnosis of new-onset left bundle branch block (LBBB)-associated idiopathic nonischemic cardiomyopathy (NICM) and treatment with guideline-directed medical therapy (GDMT) is unknown. The purpose of this study was to describe relationships between time from diagnosis to CRT and outcomes in new-onset LBBB-associated idiopathic NICM with left ventricular ejection fraction (LVEF) ≤35%. METHODS: A retrospective cohort study examined associations between time from diagnosis to CRT (≤9 months vs >9 months) and clinical and echocardiographic outcomes. RESULTS: In 123 subjects with LBBB-associated idiopathic NICM, time from diagnosis to CRT was ≤9 months in 60 (49%) subjects and 9 months in 63 (51%) subjects. Clinical outcomes were similar for those implanted ≤9 months versus >9 months for adverse clinical events (hazard ratio [HR], 0.85; 95% confidence interval [CI], 0.41-1.78; P = 0.67) and all-cause mortality (HR, 0.57; 95% CI, 0.19-1.70; P = 0.31). Multivariable analyses demonstrated similar results. In 105 subjects with post-CRT echocardiograms, LVEF improvement to >35% was more likely in those implanted ≤9 months when compared to >9 months (odds ratio [OR], 3.53; 95% CI, 1.32-9.46; P = 0.01). This association persisted in the final multivariable model adjusted for age at diagnosis, sex, QRS duration, post-GDMT LVEF, and time from CRT to post-CRT echocardiogram (OR, 5.10; 95% CI, 1.71-15.22; P = 0.004). CONCLUSION: In LBBB-associated idiopathic NICM, earlier CRT implantation was associated with more favorable cardiac remodeling. Delaying CRT may miss a critical period to halt and reverse progressive myocardial damage.

Influence of patients' age at implantation on mortality and defibrillator shocks.

AIMS: Patients have increasing comorbidities and competing causes of death with advancing age, raising questions about the effectiveness of the implantable cardioverter defibrillators (ICD) in older age. We therefore investigated the effect of patients' age at initial device implantation on all-cause mortality and on the risk of ICD shocks in single-chamber (V-ICD), dual-chamber (D-ICD), and cardiac resynchronization therapy defibrillator (CRT-D) recipients. METHODS AND RESULTS: We reviewed de-identified records of 67 128 ICD recipients enrolled in the Boston Scientific ALTITUDE database of remote monitored patients [V-ICD (n = 11 422), D-ICD (n = 23 974), and CRT-D (n = 31 732)]. Over a mean follow-up of 2.3 ± 1.4 years, patients in all ICD groups had increased all-cause mortality but decreased risk of defibrillator shocks and/or anti-tachycardia pacing per 10 year increase in age. Compared with the youngest age group (<50 years), patients in the oldest age group (≥80 years) had a 6.8-fold, 5.9-fold, and 3.4-fold increase in all-cause mortality (P < 0.001 for all comparisons) and a 31, 45, and 53% decrease in the risk of ICD shock (P ≤ 0.002 for all comparisons) for the V-ICD, D-ICD, and CRT-D groups, respectively. CONCLUSION: Older recipients of standard and CRT defibrillators have higher mortality but fewer ICD shocks and/or therapies compared with younger patients. These data highly suggest less benefit of ICD therapy with increasing age, presumably because of competing risks of non-arrhythmic mortality. The role of defibrillator therapy in older patients may need to be evaluated with randomized controlled trials.

Battery longevity from cardiac resynchronization therapy defibrillators: differences between manufacturers and discrepancies with published product performance reports.

AIMS: Cardiac resynchronization therapy (CRT) is an important treatment for heart failure that requires constant ventricular pacing, placing a high energy burden on CRT defibrillators (CRT-D). Longer battery life reduces the need for device changes and associated complications, thereby affecting patient outcomes and cost of care. We therefore investigated the time to battery depletion of CRT-D from different manufacturers and compared these results with manufacturers' published product performance reports (PPRs). METHODS AND RESULTS: All CRT-D recipients at our institution between January 2008 and December 2010 were included in this study cohort. The patients were followed up to the endpoint of battery depletion and were otherwise censored at the time of death, last follow-up, or device removal for any reason other than battery depletion. A total of 621 patients [173 Boston Scientific (BSC), 391 Medtronic (MDT), and 57 St. Jude Medical (SJM)] were followed up for a median of 3.7 (IQR 1.6-5.0) years, during which time 253 (41%) devices were replaced for battery depletion. Compared with MDT devices, battery depletion was 85 and 54% less likely to happen with BSC and SJM devices, respectively (P < 0.001 for pairwise comparisons). Product performance reports from all manufacturers significantly overestimated battery longevity by more than 20% 6 years after device implantation. CONCLUSIONS: Large differences in CRT-D battery longevity exist between manufacturers. Industry-published PPRs significantly overestimate device longevity. These data have important implications to patients, healthcare professionals, hospitals, and third-party payers.

Left ventricular dimensions predict risk of appropriate shocks but not mortality in cardiac resynchronization therapy-defibrillator recipients with left bundle-branch block and non-ischemic cardiomyopathy.

AIMS: Patients with non-ischaemic cardiomyopathy (NICM) and left bundle-branch block (LBBB) often benefit markedly from cardiac resynchronization therapy (CRT). Cardiac resynchronization therapy responders have a lower risk of appropriate device shocks from CRT-defibrillators (CRT-D) than do non-responders. Larger baseline left ventricular (LV) dimensions may be associated with less CRT response and thus greater risk of appropriate shocks. METHODS AND RESULTS: We analysed all (n = 249; 55% female) primary prevention CRT-D recipients at our institution with LBBB, NICM, and measured LV dimensions prior to device implant for the outcomes of (i) appropriate shocks, (ii) any appropriate tachyarrhythmia therapies, and (iii) risk of death, transplant, or left ventricular assist device (LVAD). During 59 months (interquartile range 21.5-91.5) follow-up, 19 (8%) patients received ≥1 appropriate shock, and 67 (27%) patients died, received a transplant, or required LVAD. Receiver-operating characteristic analysis of LV end-diastolic diameter (LVEDD) per meter height vs. appropriate shock(s) revealed an area under the curve of 0.75 (95% CI 0.65-0.85; P < 0.001). No patient with indexed LVEDD <3.36 cm/m (n = 76) received a shock. There was no statistically significant difference in risk of death, transplant, or LVAD (corrected HR 1.67, 95% CI 0.90-3.03; P = 0.103) in patients with indexed LVEDD above this cut-off compared to those with smaller dimension. Among 102 patients with paired quantitative echocardiograms, there was no difference in LVEF change between patients with indexed LVEDD <3.36 cm/m (n = 27; median 11%) and larger (n = 75; median 14%). CONCLUSION: Patients with LVEDD <3.36 cm/m height prior to CRT-D implant in the setting of NICM and LBBB have minimal risk of appropriate shocks but similar risk of death, transplant- and LVAD and similar extent of LV functional improvement as patients with larger LVEDD. CRT-pacemakers may be appropriate in such patients.

Predictors and implications of early left ventricular ejection fraction improvement in new-onset idiopathic nonischemic cardiomyopathy with narrow QRS complex: A NEOLITH substudy.

BACKGROUND: Predictors and implications of early left ventricular ejection fraction (LVEF) improvement with guideline-directed medical therapy (GDMT) in new-onset idiopathic nonischemic cardiomyopathy (NICM) with narrow QRS complex are not well described. The objectives were to describe predictors of LVEF improvement after 3 months on GDMT and adverse cardiac events based on post-GDMT LVEF status (≤35% vs. >35%). METHODS: A retrospective cohort study was performed in subjects with new-onset NICM, LVEF ≤35%, and narrow QRS complex. Associations for baseline variables with post-GDMT LVEF improvement and absolute change in LVEF (∆LVEFGDMT ) were assessed. Cox proportional hazards models assessed associations for post-GDMT LVEF status with adverse cardiac events. RESULTS: In 70 subjects, 31 (44%) had post-GDMT LVEF ≤35% after a median follow-up time of 97.5 days (interquartile range, 84-121 days). In final multivariable models, severely dilated left ventricular end-diastolic diameter (LVEDD), compared with normal LVEDD, strongly predicted post-GDMT LVEF ≤35% (odds ratio, 7.77; 95% confidence interval [CI], 1.39-43.49; p = .02) and ∆LVEFGDMT (ß = -15.709; standard error = 4.622; p = .001). Subjects with post-GDMT LVEF ≤35% were more likely to have adverse cardiac events over a median follow-up time of 970.5 days (unadjusted hazard ratio, 2.15; 95% CI, 0.93-4.96; p = .07). In the post-GDMT LVEF ≤35% group, 9 of 26 subjects (35%) had long-term LVEF > 35%. CONCLUSION: In new-onset NICM with narrow QRS complex, nondilated LVEDD predicted early LVEF improvement. Those with post-GDMT LVEF ≤35% had higher risk of adverse cardiac events, but a substantial proportion demonstrated continued long-term LVEF improvement.

Efficacy of Cryoballoon Pulmonary Vein Isolation in Patients With Persistent Atrial Fibrillation.

INTRODUCTION: Cryoballoon PVI has emerged as an alternative to radiofrequency PVI for the treatment of paroxysmal AF. The optimal strategy for patients with persistent AF is unclear as data are limited. METHODS: We analyzed a prospective registry of consecutive patients with persistent AF who underwent Cryoballoon PVI at a single center between 2011 and 2014. Patients were assessed for atrial arrhythmia recurrence after a 3-month blanking period at 6 months, 1 year, and 2 years postprocedure. Recurrence was based on typical symptoms, ECG, or event monitor evidence of AF. Kaplan-Meier analysis was used to estimate arrhythmia-free survival. RESULTS: Final analysis included 69 patients who underwent Cryoballoon PVI with a mean age 59.4 ± 8.1 years, 85.5% male, 53.6% HTN patients, CHA2DS2-VASC score 1.6 ± 1.2, and LA size 4.5 ± 0.6 cm. The single procedure atrial arrhythmia recurrence-free rate at 1-year postprocedure after a 3-month blanking period was 59% and 50% at a mean follow-up of 607 days. Of the recurrence-free group, 17% were taking previously ineffective antiarrhythmic medications. In comparing patients with persistent AF duration <1 year versus >1 year, there was a trend toward greater AF recurrence-free rates in the <1 year group (66% vs. 55%, P = 0.09). CONCLUSION: Cryoballoon PVI appears to be an effective initial strategy in treating persistent AF, with an AF recurrence-free rate of 59% at 1 year.

Clinical Characteristics and Outcomes of Older Cardiac Resynchronization Therapy Recipients Using a Pacemaker versus a Defibrillator.

BACKGROUND: Cardiac resynchronization therapy (CRT) is commonly used to manage heart failure, yet published guidelines do not distinguish between recommendations for pacemakers (CRT-P) and defibrillators (CRT-D) despite significant differences in size, longevity, and cost between these devices. The purpose of this study is to compare the clinical characteristics and outcomes between elderly recipients of CRT-P and CRT-D. METHODS AND RESULTS: Data from 512 patients (405 CRT-D, 107 CRT-P) aged ≥75 years with LV ejection fraction ≤35% and QRS duration >120 milliseconds were retrospectively analyzed for baseline characteristics and followed to the primary outcome of all-cause mortality. Cox proportional hazards models were used to adjust for possible confounders. Results were further validated through propensity matching cohorts. Compared to CRT-D recipients, CRT-P patients were older (83 years vs. 81 years, P < 0.001) and had more comorbid conditions (Charlson index = 5 [3-6] vs. 4 [3-5], P = 0.007). During 40.8 months of follow-up, there were 280 deaths. Compared to CRT-D patients, CRT-P recipients had higher unadjusted mortality (HR 1.54, 95% CI 1.15-2.08, P = 0.004). However, this difference lost significance after adjusting for baseline differences between the groups (HR 1.18, 95% CI 0.78-1.77, P = 0.435). CONCLUSION: Higher all-cause mortality in older CRT-P versus CRT-D patients is largely explained by baseline clinical and demographic differences between the two groups, which are likely the drivers of device selection in real-world clinical practice, where the published guidelines remain ambiguous. There is a need for randomized studies to determine optimal CRT device selection.

Clinical outcomes in cardiac resynchronization therapy-defibrillator recipients 80 years of age and older.

AIMS: Very elderly patients have not been well-represented in the randomized trials that established the benefits of cardiac resynchronization therapy (CRT) in heart failure (HF) patients. We therefore compared clinical outcomes in CRT-defibrillator (CRT-D) recipients ≥80 and <80 years old. METHODS AND RESULTS: We compared mortality and time to first appropriate shock in 258 consecutive CRT-D patients ≥80 years old with New York Heart Association II-IV HF, left ventricular ejection fraction ≤35%, QRS duration ≥120 ms, and no prior sustained ventricular tachyarrhythmias to 1058 patients <80 years old implanted with CRT-D during the same timeframe. Comorbidities and medical therapy differed significantly between the groups. During 52 ± 36 months, 123 (48%) patients ≥80 and 474 (45%) patients <80 died; mortality was significantly higher among patients ≥80 [corrected hazard ratio (HR) 1.39, 95% confidence interval (CI) 1.12-1.72; P = 0.003]. Among 258 patients ≥80 with device follow-up, only 20 (8%) received an appropriate shock compared with 172 (17%) shocks in 1053 patients <80 years old. Time to first appropriate shock was significantly shorter in patients <80 (corrected HR 0.51, 95% CI 0.30-0.87, P = 0.013). Older patients experienced 14 inappropriate shocks, and while life-threatening device complications were rare, complications related to the high-power components of the CRT-D system were not infrequent (n = 11). CONCLUSION: Mortality among CRT-D recipients ≥80 years old is higher than in younger patients but is not excessive. The risk of appropriate device shocks in older patients is relatively low and significantly less than in younger patients. These observations suggest that CRT-pacemakers should be given due consideration in elderly HF patients.

Characteristics and Outcomes of Concurrently Diagnosed New Rapid Atrial Fibrillation or Flutter and New Reduced Ejection Fraction.

BACKGROUND: Characteristics and outcomes of concurrently diagnosed new rapid atrial fibrillation (AF) or atrial flutter (AFL) and new heart failure with reduced left ventricular ejection fraction (LVEF) are not well described. METHODS: A retrospective cohort study of subjects referred for expedited transesophageal echocardiography-guided rhythm-control strategies for concurrent new rapid AF/AFL and new LVEF ≤ 40% diagnosed during the same admission was analyzed. RESULTS: Twenty-five subjects (median age 57 years; 96% male; 96% Caucasian; median CHA2 DS2 -VASc = 2) presented with new AF (n = 18) or AFL (n = 7) with rapid ventricular rate (median 135 beats/min) and new reduced LVEF (median 27%; range, 10-37.5%). Seven (28%) subjects had left atrial appendage thrombi (LAAT) and five (20%) subjects had heavy or binge alcohol use. Baseline characteristics were similar between those with and without LAAT. Thirteen subjects with AF and without LAAT underwent direct-current cardioversion (DCCV) and 10 (77%) had AF recurrence within 90 days. Improvement of long-term LVEF to >40% was comparable for subjects with and without initial LAAT (83% vs 94%; P = 0.46). Three of four subjects who received primary prophylaxis implantable cardioverter-defibrillators improved their LVEF to >35% after sinus rhythm maintenance. The median long-term follow-up time was 3.0 years. CONCLUSIONS: Subjects with concurrently diagnosed new rapid AF/AFL and new reduced LVEF are characterized by a high prevalence of LAAT and significant alcohol use. AF subjects without initial LAAT who underwent DCCV had a high 90-day AF recurrence rate. The presence of LAAT did not have a prognosticative effect on eventual LVEF improvement, which was observed in almost all subjects.

Health and Economic Outcomes Associated with Use of an Antimicrobial Envelope as a Standard of Care for Cardiac Implantable Electronic Device Implantation.

INTRODUCTION: Infection of cardiac implanted electrical devices (CIED) is a problem. In selected patients, use of an "antibacterial envelope" (AIGISRx®) is associated with low CIED infection rates. The value of this device when used as a standard of care is unclear. METHODS AND RESULTS: Retrospective analysis of all patients (N = 1,476) who underwent CIED implantation at a single hospital. During the study period, some implanters used the AIGISRx as a standard of care (Yes-AIGISRx Group, N = 365), whereas others did not use it at all (No-AIGISRx Group, N = 1,111). A risk score based on preoperative factors was calculated for each patient. Rates of CIED infection within 6 months were measured, and associated costs were estimated. The Yes-AIGISRx and No-AIGISRx groups had similar preoperative infection risk. In the No-AIGISRx group, 19 infections were observed (1.7%), versus 0 in the Yes-AIGISRx group (P = 0.006). The 6-month mortality rate among patients with infection was significantly greater than among those without infection (15.7% vs. 4.5%, P = 0.021). The average hospital duration for infection care was 13 days. By extrapolating the infection rate and costs observed in the No-AIGISRx group to the Yes-AIGISRx group, we estimated that there would have been 6.2 additional infections costing approximately $340,000. This cost was similar to the actual cost of the devices in the Yes-AIGISRx group, estimated at $320,000. CONCLUSIONS: Standard of care use of an antibacterial envelope as a standard of care was associated with a significantly lower rate of CIED infection, and appeared to be economically reasonable. Prospective trials to address these findings may be worthwhile.

A pilot study to assess benefit of atrial rhythm control after cardiac resynchronization therapy and atrioventricular node ablation.

BACKGROUND: Atrial fibrillation (AF) is frequently comorbid in patients receiving cardiac resynchronization therapy (CRT), and suppression is typically difficult. Herein, we sought to understand the benefit of atrial rhythm control in the setting of ventricular rate and regularity control induced by atrioventricular node (AVN) ablation. METHODS: Fifty-two patients with heart failure, persistent AF, left ventricular (LV) ejection fraction <35%, and left bundle branch block underwent cardiac resynchronization therapy (CRT) + AVN ablation, and were randomized to one of the following groups: (1) Atrial Rhythm Control (ARC); (2) AF. Patients were subsequently followed for up to 1 year. RESULTS: Similar numbers of patients in each group were lost to follow-up or have withdrawn (ARC two; AF three). Rhythm control in four patients in the ARC group was inadequate. Among the remaining patients, the incidence of death (ARC=1, AF=2) or left ventricular assist device +/- transplantation (ARC=2, AF=1) were similar. Among the remaining patients (ARC 16, AF 19), at 1 year, there were no significant differences in CRT response rate, Minnesota Living with Heart Failure survey score, 6-minute hall walk distance, ventricular tachyarrhythmia occurrence, or LV dimensions. A significantly higher hospital encounter rate among ARC patients was attributable to efforts to maintain uniform atrial rhythm. CONCLUSIONS: In this pilot study, no incremental benefit for ARC was apparent. A larger study will be necessary to adequately examine these issues.