Adaptive versus conventional cardiac resynchronisation therapy in patients with heart failure (AdaptResponse): a global, prospective, randomised controlled trial.

BACKGROUND: Continuous automatic optimisation of cardiac resynchronisation therapy (CRT), stimulating only the left ventricle to fuse with intrinsic right bundle conduction (synchronised left ventricular stimulation), might offer better outcomes than conventional CRT in patients with heart failure, left bundle branch block, and normal atrioventricular conduction. This study aimed to compare clinical outcomes of adaptive CRT versus conventional CRT in patients with heart failure with intact atrioventricular conduction and left bundle branch block. METHODS: This global, prospective, randomised controlled trial was done in 227 hospitals in 27 countries across Asia, Australia, Europe, and North America. Eligible patients were aged 18 years or older with class 2-4 heart failure, an ejection fraction of 35% or less, left bundle branch block with QRS duration of 140 ms or more (male patients) or 130 ms or more (female patients), and a baseline PR interval 200 ms or less. Patients were randomly assigned (1:1) via block permutation to adaptive CRT (an algorithm providing synchronised left ventricular stimulation) or conventional biventricular CRT using a device programmer. All patients received device programming but were masked until procedures were completed. Site staff were not masked to group assignment. The primary outcome was a composite of all-cause death or intervention for heart failure decompensation and was assessed in the intention-to-treat population. Safety events were collected and reported in the intention-to-treat population. This study is registered with ClinicalTrials.gov, NCT02205359, and is closed to accrual. FINDINGS: Between Aug 5, 2014, and Jan 31, 2019, of 3797 patients enrolled, 3617 (95·3%) were randomly assigned (1810 to adaptive CRT and 1807 to conventional CRT). The futility boundary was crossed at the third interim analysis on June 23, 2022, when the decision was made to stop the trial early. 1568 (43·4%) of 3617 patients were female and 2049 (56·6%) were male. Median follow-up was 59·0 months (IQR 45-72). A primary outcome event occurred in 430 of 1810 patients (Kaplan-Meier occurrence rate 23·5% [95% CI 21·3-25·5] at 60 months) in the adaptive CRT group and in 470 of 1807 patients (25·7% [23·5-27·8] at 60 months) in the conventional CRT group (hazard ratio 0·89, 95% CI 0·78-1·01; p=0·077). System-related adverse events were reported in 452 (25·0%) of 1810 patients in the adaptive CRT group and 440 (24·3%) of 1807 patients in the conventional CRT group. INTERPRETATION: Compared with conventional CRT, adaptive CRT did not significantly reduce the incidence of all-cause death or intervention for heart failure decompensation in the included population of patients with heart failure, left bundle branch block, and intact AV conduction. Death and heart failure decompensation rates were low with both CRT therapies, suggesting a greater response to CRT occurred in this population than in patients in previous trials. FUNDING: Medtronic.

Durability of left bundle branch area pacing.

BACKGROUND: Left bundle branch area pacing (LBBAP) is a form of conduction system pacing. Long-term data on the safety and performance of LBBAP 1 year postdevice implantation has not been well described. METHODS AND RESULTS: Sixty-five patients (49% females) who received LBBAP for bradycardia indications using the SelectSecure 3830 lead (Medtronic) were retrospectively evaluated. Clinical variables were examined. Lead parameters were obtained at implant and during regular follow-up. Mean age of patients was 75.7 ± 10.1 years with left ventricular ejection fraction 59.8 ± 10.4%. Indications for pacing were atrioventricular block 55%, sinus node dysfunction 19%, tachy-brady syndrome 15%, atrioventricular node ablation 8%, and bail out cardiac resynchronization therapy 3%. Mean baseline QRS measured 120 ± 38 ms, paced QRS duration was 138 ± 22ms. Paced QRS narrowed by 24 ms in those with pre-existing left bundle branch block (BBB), increased by 1 ms in those with pre-existing right BBB, and increased by 42 ms in those with no BBB. LBBAP threshold at implant was 0.521 ± 0.153 V at 0.4 ms, and increased to 0.654 ± 0.186 V at 3 months (+26%), 0.707 ± 0.186 V at 6 months (+36%), and 0.772 ± 0.220 V at 12 months (+48%). Patients with left BBB showed the maximum benefit with QRS narrowing 24 ms. Pacing impedance remained unchanged with no procedure-related complications. CONCLUSION: LBBAP is a durable form of conduction system pacing with pacing thresholds remaining relatively stable over 12 months post device implantation. Patients with left BBB display the narrowest paced QRS.

Atrial fibrillation in hypertrophic cardiomyopathy: prevalence, clinical impact, and management.

Hypertrophic cardiomyopathy (HCM) is the most common hereditary cardiomyopathy characterized by left ventricular hypertrophy and spectrum of clinical manifestation. Atrial fibrillation (AF) is a common sustained arrhythmia in HCM patients and is primarily related to left atrial dilatation and remodeling. There are several clinical, electrocardiographic (ECG), and echocardiographic (ECHO) features that have been associated with development of AF in HCM patients; strongest predictors are left atrial size, age, and heart failure class. AF can lead to progressive functional decline, worsening heart failure and increased risk for systemic thromboembolism. The management of AF in HCM patient focuses on symptom alleviation (managed with rate and/or rhythm control methods) and prevention of complications such as thromboembolism (prevented with anticoagulation). Finally, recent evidence suggests that early rhythm control strategy may result in more favorable short- and long-term outcomes.

Right ventricular apical versus non-apical implantable cardioverter defibrillator lead: A systematic review and meta-analysis.

INTRODUCTION: We aimed to study the effect of right ventricular implantable cardioverter defibrillator (ICD) lead positioning on clinical outcomes in patients undergoing ICD placement. METHODS: A systematic literature search was performed using PubMed, EMBASE, Web of Science, and Cochrane Central Register of Controlled Trials to identify clinical trials comparing outcomes in patients with ICD leads in apical and non-apical positions. The primary outcome of our study was death at 1-year follow-up. Secondary outcomes studied were "death at 3years", "total number of shocks", "appropriate shocks", "inappropriate shocks" and "cut-to-suture time". RESULTS: We analyzed a total of 3731 patients (2852 in apical and 879 in non-apical ICD groups) enrolled in 4 clinical trials. No significant difference was observed between the apical and non-apical ICD groups in all-cause mortality at 1year (OR 0.88; 95% CI 0.51-1.49, p=0.63; I2=5.32%). Similarly, no differences were seen between the two groups in death at 3years (OR=0.76; 95% CI 0.56-1.04, p=0.08; I2=0%), total number of shocks (OR 0.99; 95% CI 0.81-1.22, p=0.95; I2=0%), appropriate shocks (OR 1.00; 95% CI 0.79-1.27, p=0.99; I2=0%), inappropriate shocks (OR 0.98; 95% CI 0.70-1.37, p=0.91; I2=0%) and cut-to-suture time (Standard mean difference=-0.03; 95% CI -0.20 to 0.14, p=0.73; I2=0%). No publication bias was seen. CONCLUSION: Non-apical RV ICD lead implantation is non-inferior to traditional RV apical position with no significant differences in mortality, total number of shocks, appropriate shocks, inappropriate shocks and procedural time.

Global LEADR pivotal trial results.

BACKGROUND: Implantable cardioverter-defibrillators last longer, and interest in reliable leads with targeted lead placement is growing. The OmniaSecure™ defibrillation lead is a novel small-diameter, catheter-delivered lead designed for targeted placement, based on the established SelectSecure SureScan MRI Model 3830 lumenless pacing lead platform. OBJECTIVE: This trial assessed safety and efficacy of the OmniaSecure defibrillation lead. METHODS: The worldwide LEADR pivotal clinical trial enrolled patients indicated for de novo implantation of a primary or secondary prevention implantable cardioverter-defibrillator/cardiac resynchronization therapy defibrillator, all of whom received the study lead. The primary efficacy end point was successful defibrillation at implantation per protocol. The primary safety end point was freedom from study lead-related major complications at 6 months. The primary efficacy and safety objectives were met if the lower bound of the 2-sided 95% credible interval was >88% and >90%, respectively. RESULTS: In total, 643 patients successfully received the study lead, and 505 patients have completed 12-month follow-up. The lead was placed in the desired right ventricular location in 99.5% of patients. Defibrillation testing at implantation was completed in 119 patients, with success in 97.5%. The Kaplan-Meier estimated freedom from study lead-related major complications was 97.1% at 6 and 12 months. The trial exceeded the primary efficacy and safety objective thresholds. There were zero study lead fractures and electrical performance was stable throughout the mean follow-up of 12.7 ± 4.8 months (mean ± SD). CONCLUSION: The OmniaSecure lead exceeded prespecified primary end point performance goals for safety and efficacy, demonstrating high defibrillation success and a low occurrence of lead-related major complications with zero lead fractures.

Role of Prophylactic Magnesium Supplementation in Prevention of Postoperative Atrial Fibrillation in Patients Undergoing Coronary Artery Bypass Grafting: a Systematic Review and Meta-Analysis of 20 Randomized Controlled Trials.

BACKGROUND: Several randomized trials have evaluated the efficacy of prophylactic magnesium (Mg) supplementation in prevention of post-operative atrial fibrillation (POAF) in patients undergoing cardiac artery bypass grafting (CABG). We aimed to determine the role of prophylactic Mg in 3 different settings (intraoperative, postoperative, intraoperative plus postoperative) in prevention of POAF. METHODS: A systemic literature search was performed (until January 19, 2019) using PubMed, EMBASE, Web of Science, and Cochrane Central Register of Controlled Trials to identify trials evaluating Mg supplementation post CABG. Primary outcome of our study was reduction in POAF post CABG. RESULTS: We included a total of 2,430 participants (1,196 in the Mg group and 1,234 in the placebo group) enrolled in 20 randomized controlled trials. Pooled analysis demonstrated no reduction in POAF between the two groups (RR 0.90; 95% CI, 0.79-1.03; p=0.13; I2=42.9%). In subgroup analysis, significant reduction in POAF was observed with postoperative Mg supplementation (RR 0.76; 95% CI, 0.58-0.99; p=0.04; I2=17.6%) but not with intraoperative or intraoperative plus postoperative Mg supplementation (RR 0.77; 95% CI, 0.49-1.22; p = 0.27; I2=49% and RR 0.92; 95% CI, 0.68-1.24; p = 0.58; I2=51.8%, respectively). CONCLUSIONS: Magnesium supplementation, especially in the postoperative period, is an effective strategy in reducing POAF following CABG.

His Bundle Pacing: Hemodynamics and Clinical Outcomes.

From 1993 to 2009, nearly 2.9 million pacemakers were implanted in the United States; the majority of which were dual-chamber pacemakers. One of the major physiologic advantages of dual-chamber pacing over single-chamber ventricular pacing is atrioventricular synchrony, which prevents the pacemaker syndrome. However, patients who are pacemaker dependent or use right ventricle (RV) apical pacing more than 40% of the time are at a risk of developing heart failure from electromechanical dyssynchrony. Studies have also shown that RV pacing results in nonphysiological activation of the left ventricle, leading to adverse clinical outcomes. Hence, alternative pacing sites, including the RV outflow tract, the high-RV septal region, bi-ventricular pacing, or His bundle pacing, have been explored for a better physiological electromechanical coupling of the ventricles. Although His bundle pacing has gained attention due to favorable data and clinical outcomes, it has not gained widespread acceptance into clinical practice. Hence, we aim to review the current experience with His bundle pacing and its clinical implications in this article.

Thirty-day readmissions after cardiac implantable electronic devices in the United States: Insights from the Nationwide Readmissions Database.

BACKGROUND: Limited data are available regarding true estimates of individual complications contributing to readmissions after cardiac implantable electronic device (CIED) implantation. OBJECTIVE: The purpose of this study was to identify predictors of 30-day readmission in patients admitted for CIED implantation. METHODS: The study cohort consisted of patients who underwent CIED implantation in 2014, identified from the National Readmission Database. Readmission was defined as a subsequent hospital admission within 30 days after the discharge day of index admission. If patients had more than 1 readmission within 30 days, only the first readmission was included. RESULTS: Our final cohort consisted of 70,223 cases, 61,738 (88%) in the no-readmission group and 8485 patients (12%) in the readmission group. Female gender (odds ratio [OR] 1.09; 95% confidence interval [CI] 1.04-1.14; P = .001), atrial fibrillation/flutter (OR 1.23; 95% CI 1.17-1.29, P <.001), acute renal failure (OR 1.65; 95% CI 1.56-1.74; P <.001), coronary artery disease (OR 1.09; 95% CI 1.03-1.14; P = .002), length of stay (OR 1.70; 95% CI 1.51-1.89; P <.001), device placement on the day of admission (OR 0.87; 95% CI 0.80-0.95, P = .001), and fourth quartile of hospital procedure volume (OR 0.91; 95% CI 0.84-0.99; P = .03; first quartile of hospital procedure volume as reference) were independent predictors of 30-day readmissions. The 30-day readmission resulted in additional median charges of $30,692 per patient. Device-related complications were seen in 10.7% of readmitted patients. The most common complications were mechanical (2.8%) and infectious (2.6%). CONCLUSION: Several patient and hospital-related factors were identified to be independent predictors of 30-day readmission, accounting for increased health care cost.

Right Ventricular and Chest Wall Perforation with Implantable Cardioverter-Defibrillator Lead with Lodgment into the Cutaneous Tissue of the Chest Wall.

Implantable cardioverter-defibrillator (ICD) lead perforation is a rare but serious complication of cardiac device implantation. Subacute (24 h to one month) and delayed (>1 month) presentations of rupture are also rare. Here we report a case of right ventricular perforation by a ventricular ICD lead in a 61-year-old man that was detected four months' postimplantation. The lead was present out from his chest wall and was palpable beneath the skin.

Influence of Pregnancy in Patients With Congenital Long QT Syndrome.

Congenital long QT syndrome (LQTS) is a disorder of myocardial repolarization and is characterized by a prolonged QT interval on an electrocardiogram. A prolonged QT predisposes patients to an increased risk of syncope and sudden cardiac death secondary to polymorphic ventricular tachycardia. Several mutations linked to the LQTS have been identified, the most common of which have been found in the potassium channel KCNQ1 (LQT1) and hERG (LQT2) genes and in the sodium channel SCN5A (LQT3) gene. Female sex is an independent risk factor for the development of torsades de pointes in LQTS. Furthermore, although pregnancy may be associated with protection against cardiac events in LQTS, the 9-month postpartum period represents a time of increased arrhythmogenicity. Interestingly, these cardiac events during the postpartum period are more common in patients with LQT2. The precise mechanisms that influence the cardiac repolarization during the postpartum period are unclear. Beta-blockers are considered reasonably safe during pregnancy and should be continued or initiated in patients with LQTS to reduce the risk of cardiac events. Implantable cardioverter defibrillators are safe in pregnancy, and there is no evidence that pregnant women with these devices are at any greater risk for adverse complications solely on the grounds of having the device.

Catheter ablation of accessory pathway: 14-year trends in utilization and complications in adults in the United States.

BACKGROUND: The aim of this study was to determine the temporal trends in utilization of catheter ablation of accessory pathways in the United States. METHODS: All patients from the Nationwide Inpatient Sample (NIS) ≥18years of age with a primary diagnosis of anomalous atrioventricular excitation syndrome (International Classification of Diseases, Ninth Edition, Clinical Modification [ICD-9-CM] code 426.7) were included in the study. Patients who underwent catheter ablation were identified using ICD-9-CM procedure code 37.34. Patients with a concomitant diagnosis of atrial fibrillation, atrial flutter, atrial tachycardia or ventricular arrhythmias were excluded from the analysis. Annual hospital volume was identified using unique hospital identification number and was divided into tertiles for further analysis. RESULTS: A total of 11,601 catheter ablations for anomalous atrioventricular excitation syndrome were studied from 1998 to 2011. The mean length of stay was 1.8days (median 1day). The utilization trends of accessory pathway ablation have steadily declined from 3.9 ablation procedures/million US population in 1998-1999 to 2.5 ablation procedures/million US population in 2010-2011. The second tertile (adjusted OR 0.41; 95% CI 0.20-0.83, p=0.01) and third tertile (adjusted OR 0.39; 95% CI 0.18-0.85, p=0.02) of hospital volume were associated with reduction in cardiac complications as compared to first tertile of hospital volume. Advanced age (OR 1.02, 95% CI 1.01-1.04, p=0.002) was independent predictor of cardiac complications. There were no in-hospital deaths. CONCLUSION: Despite decline in ablation trends, it still remains a relatively safe procedure associated with low morbidity and no mortality.

Role of implantable cardioverter defibrillator in non-ischemic cardiomyopathy: a systematic review and meta-analysis of prospective randomized clinical trials.

INTRODUCTION: A mortality benefit in patients with implantable cardioverter defibrillator (ICD) in ischemic cardiomyopathy is well established. However, the benefit of ICD implantation in non-ischemic cardiomyopathy (NICM) on total mortality remains uncertain. We performed a systematic review and meta-analysis of randomized controlled trials (RCT) evaluating the role of primary prevention ICD in NICM patients. METHODS: We performed a systematic review on PubMed, The Cochrane Library, EMBASE, EBSCO, Web of Science, and CINAHL databases from the inception through February 2017 to identify RCT evaluating the role of ICD in NICM patients. Mantel-Haenszel risk ratio (RR) fixed effects model was used to summarize data across treatment arms. If heterogeneity (I 2) ≥25, random effects model was used instead. RESULTS: We analyzed a total of 2573 patients from five RCTs comparing ICD with medical therapy in patients with NICM. The mean follow up for the trials was 48 ± 22 months. There was a significant reduction in (a) all-cause mortality (RR 0.84, 95% CI 0.71-0.99, p = 0.03) and (b) sudden cardiac death (RR 0.47, 95% CI 0.30-0.73, p < 0.001) in ICD group versus medical therapy. CONCLUSION: Our analysis demonstrates that the use of ICD for primary prevention is associated with a reduction in all-cause mortality and SCD in patients with NICM.

Safety And Efficacy Of Uninterrupted Periprocedural Apixaban In Patients Undergoing Atrial Fibrillation Catheter Ablation: A Metaanalysis Of 1,057 Patients.

Apixaban (factor Xa inhibitor) is a novel anticoagulant and may be beneficial during atrial fibrillation (AF) ablation for prevention of thromboembolic events. However, the adverse effects of periprocedural apixaban therapy have not been thoroughly evaluated. A meta-analysis was performed to evaluate the safety of apixaban for anticoagulation in AF ablation. We searched the online databases till October 2015 for studies comparing Apixaban with Vitamin K antagonists in atrial fibrillation patients undergoing catheter ablation. Primary outcome of our study was composite of thromboembolic event and bleeding (includes major and minor bleeding). A total of 1,057 atrial fibrillation patients in 3 studies undergoing catheter ablation were included in this analysis. Zero thromboembolic events were reported in the apixaban group and 1 in the VKA group with no statistical difference (OR 0.75; 95% CI 0.03-18.49). No major differences were observed for the primary outcome (OR 0.92; 95% CI 0.54-1.55), risk of overall bleeding (OR 0.94, 95% CI 0.55- 1.58), major bleeding (OR1.37; 95% CI 0.33-5.67), minor bleeding (OR 0.89; 95% CI 0.50-1.55), pericardial effusion (OR 0.50; 95% CI 0.18-1.38) and groin hematoma (OR 1.36; 95% CI 0.70-2.65). Uninterrupted apixaban administration in patients undergoing AF catheter ablation was non-inferior to VKA without increasing the risk of major and minor bleeding.

Gastrointestinal complications associated with catheter ablation for atrial fibrillation.

Atrial fibrillation is the most common arrhythmia in the United States. With the ageing population, the incidence and prevalence of atrial fibrillation are on the rise. Catheter ablation of atrial fibrillation is a widely accepted treatment modality in patients with drug refractory symptomatic paroxysmal or persistent atrial fibrillation. The close proximity to the left atrium posterior wall makes the thermosensitive esophagus a potential site of injury during catheter ablation of AF leading to various gastrointestinal complications. The major gastrointestinal complications associated with catheter ablation include atrioesophageal fistula, gastroparesis, esophageal thermal lesions and esophageal ulcers. Multiple studies, case reports and series have described these complications with various catheter ablation techniques such as radiofrequency, cryoenergy and high frequency focused ultrasound energy ablation. This review addresses the gastrointestinal complications after AF ablation procedures and aims to provide the clinicians with an overview of clinical presentation, etiology, pathogenesis, prevention and management of these conditions.

Safety and efficacy of oral factor-Xa inhibitors versus Vitamin K antagonist in patients with non-valvular atrial fibrillation: Meta-analysis of phase II and III randomized controlled trials.

BACKGROUND: Aim of our study was to assess the safety and efficacy on factor-Xa inhibitors (FXIs) in patients with non-valvular atrial fibrillation (NVAF) as compared to Vitamin K antagonist (VKA). METHODS: Phase II and III randomized controlled trials that reported clinical safety and efficacy of FXI in patients with NVAF were identified from MEDLINE, Embase, and Cochrane Central Register of Controlled Trials through December 10, 2015. The primary safety outcome of our study was composite of stroke and systemic embolic event. Secondary outcomes studied were individual endpoints of primary safety outcome, major bleeding, clinically relevant non-major bleed (CRNMB), and all-cause mortality. RESULTS: We included 11 RCTs with a total of 59,164 participants, of which 34,231 patients received oral FXI and 24,933 patients were on VKA with a mean follow-up of 369days. There was a significant reduction in primary outcome with FXI compared to VKA, 1,112 (3.4%) versus 816 (3.6%) events, respectively (OR 0.82; 95% CI 0.68-0.99). Use of FXI significantly reduced major bleeding events compared to VKA, OR 0.74, 95% CI 0.58-0.96, test for heterogeneity (I(2)=74%). Incidence of CRNMB was not different between FXI and VKA groups, OR 0.84, 95% CI 0.68-1.04. There was a significant reduction in all-cause mortality in FXI group compared to VKA group, OR 0.88, 95% CI 0.83-0.94 with no significant heterogeneity. CONCLUSION: Use of FXI was associated with a significant reduction in major bleeding events and all-cause mortality without increased risk of stroke or SEE compared to VKA.

Cryoballoon versus Radiofrequency Ablation for Atrial Fibrillation: A Meta-analysis of 16 Clinical Trials.

Introduction: We aimed to study the procedural characteristics, efficacy and safety of cryoballoon ablation (CBA) versus radiofrequency ablation (RFA) for catheter ablation of paroxysmal atrial fibrillation (AF). Methods: A systematic literature search was performed using PubMed, EMBASE, Web of Science, and Cochrane Central Register of Controlled Trials to clinical trials comparing CBA and RFA for AF. Outcomes were evaluated for efficacy, procedure characteristics and safety. For each study, odd ratio (OR) and 95% confidence intervals (CIs) were calculated for endpoints for both approaches. Results: We analyzed a total of 9,957 participants (3,369 in the CBA and 6,588 in RFA group) enrolled in 16 clinical trials. No significant difference was observed between CBA and RFA with regards to freedom from atrial arrhythmia at 12-months, recurrent atrial arrhythmias or repeat catheter ablation. CBA group had a significantly higher transient phrenic nerve injury (OR 14.19, 95% CI: 6.92-29.10; p<0.001) and persistent phrenic nerve injury (OR 4.62, 95% CI: 1.97-10.81; p<0.001); and a significantly lower pericardial effusion/cardiac tamponade (OR 0.43, 95% CI: 0.26-0.72; p=0.001), and groin site complications (OR 0.60, 95% CI: 0.38-0.93; p=0.02). No significant difference was observed in overall complications, stroke/thromboembolic events, major bleeding, and minor bleeding. Conclusion: CBA was non-inferior to RFA for catheter ablation of paroxysmal AF. RF ablation was associated with a higher groin complications and pericardial effusion/cardiac tamponade, whereas CBA was associated with higher rates of transient and persistent phrenic nerve injury.