Epidemiology, evaluation, and management of conduction disturbances after transcatheter aortic valve replacement

Aortic stenosis is the most common valvulopathy requiring replacement by means of the surgical or transcatheter approach. Transcatheter aortic valve replacement (TAVR) has quickly become a viable and often preferred treatment strategy compared to surgical aortic valve replacement. However, transcatheter heart valve system deployment not infrequently injures the specialized electrical system of the heart, leading to new conduction disorders including high-grade atrioventricular block and complete heart block (CHB) necessitating permanent pacemaker implantation (PPI), which may lead to deleterious effects on cardiac function and patient outcomes. Additional conduction disturbances (e.g., new-onset persistent left bundle branch block, PR/QRS prolongation, and transient CHB) currently lack clearly defined management algorithms leading to variable strategies among institutions. This article outlines the current understanding of the pathophysiology, patient and procedural risk factors, means for further risk stratification and monitoring of patients without a clear indication for PPI, our institutional approach, and future directions in the management and evaluation of post-TAVR conduction disturbances.

Dual vs Single Cardioversion of Atrial Fibrillation in Patients With Obesity: A Randomized Clinical Trial

Importance

Atrial fibrillation and obesity are common, and both are increasing in prevalence. Obesity is associated with failure of cardioversion of atrial fibrillation using a standard single set of defibrillator pads, even at high output.

Objective

To compare the efficacy and safety of dual direct-current cardioversion (DCCV) using 2 sets of pads, with each pair simultaneously delivering 200 J, with traditional single 200-J DCCV using 1 set of pads in patients with obesity and atrial fibrillation.

Design, Setting, and Participants

This was a prospective, investigator-initiated, patient-blinded, randomized clinical trial spanning 3 years from August 2020 to 2023. As a multicenter trial, the setting included 3 sites in Louisiana. Eligibility criteria included body mass index (BMI) of 35 or higher (calculated as weight in kilograms divided by height in meters squared), age 18 years or older, and planned nonemergent electrical cardioversion for atrial fibrillation. Patients who met inclusion criteria were randomized 1:1. Exclusions occurred due to spontaneous cardioversion, instability, thrombus, or BMI below threshold.

Interventions

Dual DCCV vs single DCCV.

Main Outcomes and Measures

Return to sinus rhythm, regardless of duration, immediately after the first cardioversion attempt of atrial fibrillation, adverse cardiovascular events, and chest discomfort after the procedure.

Results

Of 2079 sequential patients undergoing cardioversion, 276 met inclusion criteria and were approached for participation. Of these, 210 participants were randomized 1:1. After exclusions, 200 patients (median [IQR] age, 67.6 [60.1-72.4] years; 127 male [63.5%]) completed the study. The mean (SD) BMI was 41.2 (6.5). Cardioversion was successful more often with dual DCCV compared with single DCCV (97 of 99 patients [98%] vs 87 of 101 patients [86%]; P = .002). Dual cardioversion predicted success (odds ratio, 6.7; 95% CI, 3.3-13.6; P = .01). Patients in the single cardioversion cohort whose first attempt failed underwent dual cardioversion with all subsequent attempts (up to 3 total), all of which were successful: 12 of 14 after second cardioversion and 2 of 14 after third cardioversion. There was no difference in the rating of postprocedure chest discomfort (median in both groups = 0 of 10; P = .40). There were no cardiovascular complications.

Conclusions and Relevance

In patients with obesity (BMI ≥35) undergoing electrical cardioversion for atrial fibrillation, dual DCCV results in greater cardioversion success compared with single DCCV, without any increase in complications or patient discomfort.

Trial Registration

ClinicalTrials.gov Identifier: NCT04539158.

Risk of ventricular arrhythmias following implantable cardioverter-defibrillator generator change in patients with recovered ejection fraction: Implications for shared decision-making

INTRODUCTION

Guidelines indicate primary-prevention implantable cardioverter-defibrillators (ICDs) for most patients with left ventricular ejection fraction (LVEF) ≤ 35%. Some patients' LVEFs improve during the life of their first ICD. In patients with recovered LVEF who never received appropriate ICD therapy, the utility of generator replacement upon battery depletion remains unclear. Here, we evaluate ICD therapy based on LVEF at the time of generator change, to educate shared decision-making regarding whether to replace the depleted ICD.

METHODS

We followed patients with a primary-prevention ICD who underwent generator change. Patients who received appropriate ICD therapy for ventricular tachycardia or ventricular fibrillation (VT/VF) before generator change were excluded. The primary endpoint was appropriate ICD therapy, adjusted for the competing risk of death.

RESULTS

Among 951 generator changes, 423 met inclusion criteria. During 3.4 ± 2.2 years follow-up, 78 (18%) received appropriate therapy for VT/VF. Compared to patients with recovered LVEF > 35% (n = 161 [38%]), those with LVEF ≤ 35% (n = 262 [62%]) were more likely to require ICD therapy (p = .002; Fine-Gray adjusted 5-year event rates: 12.7% vs. 25.0%). Receiver operating characteristic analysis revealed the optimal LVEF cutoff for VT/VF prediction to be 45%, the use of which further improved risk stratification (p < .001), with Fine-Gray adjusted 5-year rates 6.2% versus 25.1%.

CONCLUSION

Following ICD generator change, patients with primary-prevention ICDs and recovered LVEF have significantly lower risk of subsequent ventricular arrhythmias compared to those with persistent LVEF depression. Risk stratification at LVEF 45% offers significant additional negative predictive value over a 35% cutoff, without a significant loss in sensitivity. These data may be useful during shared decision-making at the time of ICD generator battery depletion.

The role of atrial fibrillation catheter ablation in patients with heart failure

Atrial Fibrillation (AF) and heart failure (HF) with reduced ejection fraction (HFrEF) frequently coexist, resulting in significant morbidity and mortality. Therapeutic options for patients with AF and HFrEF are limited due to few antiarrhythmic drug (AAD) choices and historically equivocal effects of procedural interventions on mortality. However, recent randomized trials examining catheter ablation (CA) in AF patients with HFrEF have shown a beneficial effect on arrhythmic burden and HF symptoms, as well as an improvement in mortality. This review focuses on the role of CA for AF patients with HFrEF.

Sacubitril/Valsartan: An Antiarrhythmic Drug?

Heart failure (HF) is a major cause of morbidity and mortality, with nearly half of all HF-related deaths resulting from sudden cardiac death (SCD), most often from an arrhythmic event. The pathophysiologic changes that occur in response to the hemodynamic stress of HF may lead to increased arrhythmogenesis. Theoretically, medications that block these arrhythmogenic substrates would decrease the risk of SCD. Sacubitril/valsartan, the combined angiotensin receptor and neprilysin inhibitor (ARNi; tradename Entresto), has been shown to decrease cardiovascular mortality and hospitalization in patients with HF with reduced ejection fraction (HFrEF). Emerging evidence suggests that ARNi also may play a role in reducing arrhythmogenesis and thereby SCD. This review summarizes the current data regarding this ARNi and its potential antiarrhythmic effects. This article is protected by copyright. All rights reserved.

Serial secretoneurin measurement and risk of ventricular arrhythmias and death in patients with left ventricular systolic dysfunction

BACKGROUND

Secretoneurin, a member of the granin protein family, is associated with the risk of mortality in patients with acute and chronic heart failure. Secretoneurin may play an important role in cardiomyocyte calcium handling, suggesting that it may influence cardiac arrhythmia risk. We hypothesized that baseline and serial measurements of circulating secretoneurin are associated with the risk of incident ventricular tachyarrhythmias (VA) and death, and that serial measurement would provide prognostic information beyond baseline values.

METHODS

We measured circulating secretoneurin concentrations in blood samples obtained at 3-month intervals for one year in a prospectively enrolled cohort of ambulatory patients with left ventricular ejection fraction (LVEF) ≤ 35 % and a primary-prevention implanted cardioverter defibrillator (ICD). Associations between secretoneurin modeled as a time-dependent variable and the incidences of VA and death were assessed.

RESULTS

154 patients (66 ± 14 years, LVEF 23 ± 8 %) were included in the analysis. During one-year follow-up, 26 (17 %) patients experienced VA, and 16 (10 %) died. Adjusting for age, sex, eGFR, and LVEF, baseline secretoneurin concentration was associated with the risk of death (hazard ratio (HR) per 10 pmol/L increase: 1.14 (95 % CI: 1.02-1.27), p = 0.020) but not VA (HR: 0.98 (0.81-1.19), p = 0.856). Using serial measurements at 3-month intervals, time-varying secretoneurin was associated with a similarly higher risk of death (HR: 1.14 (1.02-1.27), p = 0.017) but not of VA (HR: 0.97 (0.81-1.17), p = 0.776).

CONCLUSION

In stable ambulatory patients with reduced LV systolic function and a primary prevention indication for ICD, secretoneurin concentration was associated with the risk of death but not ventricular tachyarrhythmia.