Callahan, Thomas D

BACKGROUND: MODULAR antitachycardia pacing (ATP), a multicenter, international trial, assesses a modular cardiac rhythm management system: a subcutaneous implantable cardioverter defibrillator in wireless communication with a leadless pacemaker (LP) capable of pace-terminating ventricular tachycardia. METHODS: Enrolees had one or more clinical risk factors for ventricular tachycardia and did not require chronic pacing. Complications included prespecified major LP system- and procedure-related complications, and any complication related to the LP, subcutaneous implantable cardioverter defibrillator, implantation, or study protocol. Survival analysis was performed to identify complication-free rates, therapy delivery, and all-cause mortality. RESULTS: The 297 patients enrolled had an ejection fraction of 35±13%, 43% secondary prevention indications, and 59% with prior ventricular arrhythmias. Of 286 patients undergoing LP implantation (100% success), 251 patients completed 12-month follow-up. Mortality rate was 6%, with none related to the implant procedure. Median follow-up duration was 23.4 months (interquartile range, 17.9–28.1). The LP major complication-free rate was 97.2%, exceeding the performance goal. The overall LP+ subcutaneous implantable cardioverter defibrillator system-related complication-free rate was 88.5%. Appropriate tachyarrhythmia-therapy (ATP+shock) rates were 14.4%, and appropriate shock rates were 8.5%. Inappropriate total tachyarrhythmia therapy was 9.5% of which 8.5% were shocks. ATP was 67.3% successful in terminating ventricular arrhythmia episodes and accelerated ventricular arrhythmias in 10.1% of episodes. Overall therapy burden (ATP+shock) was 96/100 patient-years, of which 44/100 patient-years was for shock delivery. CONCLUSIONS: One-year outcomes of the first modular pacing-defibrillator system reveal low system and LP complication rates and good ATP efficacy rates, suggesting that the modular cardiac rhythm management is a viable alternative to single-chamber implantable cardioverter defibrillators using low-energy pacing capability without the need for transvenous leads. CLINICAL TRIAL REGISTRATION: URL: https://clinicaltrials.gov/ ; Unique identifier: NCT04798768.

Introduction: Increasingly, catheter ablation for atrial fibrillation (AF) has been utilized for rhythm control and to improve quality of life (QoL). Data are limited on patient-centered ablation outcomes in individuals with chronic kidney disease (CKD). Objective: To examine clinical outcomes and QoL following AF ablation in CKD patients from a large patient-reported outcomes (PRO) database. Methods: All patients undergoing AF ablation (2013-2016) at our center were enrolled and assessed for outcomes using automated PRO surveys (baseline, 3 and 6 months after ablation, every 6 months thereafter). This analysis captured data at 1- and 3-year follow-up. CKD was defined as estimated glomerular filtration rate (eGFR) <60 ml/min using the 2021 CKD-EPI equation. The atrial fibrillation symptom severity scale (AFSSS) was used as the main measure for QoL assessment. In addition, data were collected on clinical improvement by patient report, AF burden, and healthcare utilization. Results: A total of 488 patients were identified (66% male, mean age 68.5, 56.2% persistent AF). QoL was significantly improved from baseline median (IQR) AFSSS of 14 (6-19.5) to 3 (0-9) at 1-year and 4 (0-9.5) at 3-year; P≤0.0001 for both. About 90% of patients reported improvement in their overall AF-related symptoms both at 1- and 3-year follow up. The proportion of patients in AF at the time of completion of the baseline survey was 51.2%, and this decreased to 6.2% at 1-year and 9.7% at 3-year follow up (P<0.0001 for both). AF burden was significantly reduced at 1-year and 3-year including frequency and duration of episodes (P<0.05 for both), with associated decrease in ER visits and hospitalizations; P<0.0001 for all comparisons. The proportion of patients on antiarrhythmics decreased from 61.8% at baseline to 35.6% and 22.7% at 1-year and 3-year, respectively (P<0.0001 for both). Conclusions: In a large AF-specific PRO system, catheter ablation for AF was associated with a significant improvement of QoL in most patients with CKD; with a decrease in AF burden and healthcare utilization.

Background: Atrial fibrillation (AF) ablation targets improvement in quality of life (QoL). Data is scarce on predictors of QoL improvement following ablation. We aimed to investigate the clinical characteristics underlying differential response in QoL after AF ablation (with or without arrhythmia recurrence). Methods: All patients undergoing AF ablation (2013–2016) at our center were prospectively enrolled in a fully automated patient-reported outcomes registry. A large number of variables were collected including AF symptom severity scale and AF burden (as indicated by AF frequency and duration scores). Patients were divided into 3 groups based on self-report of QoL improvement: remarkable (super responders), mild/moderate, and unchanged or worse (nonresponders). Univariable and multivariable logistic regression models assessed clinical characteristics and QoL outcomes. Results: A total of 956 patients were included (25% females, mean age 63.9). Most patients (≈80%) were super responders (n=761), 138 (14.4%) had mild/moderate improvement, and 57 (5.9%) were nonresponders. The strongest predictors of remarkable QoL improvement were freedom of arrhythmia recurrence (OR, 2.42 [95% CI, 1.27–4.59], P =0.007) and lower AF burden at 12 months. Similarly, higher AF burden was significantly associated with clinical nonresponse. In patients with observed clinical recurrence-QoL mismatch, changes in AF burden at 12 months were the main predictors of QoL outcome, with lower burden predicting higher improvement in QoL and vice versa. Conclusions: Most patients derive significant QoL benefit from AF ablation. Freedom from arrhythmia recurrence and lower AF burden predict remarkable QoL improvement following ablation.

Cardiac sarcoidosis is a component of an often multiorgan granulomatous disease of still uncertain cause. It is being recognized with increasing frequency, mainly as the result of heightened awareness and new diagnostic tests, specifically cardiac magnetic resonance imaging and 18 F-fluorodeoxyglucose positron emission tomography scans. The purpose of this case-based review is to highlight the potentially life-saving importance of making the early diagnosis of cardiac sarcoidosis using these new tools and to provide a framework for the optimal care of patients with this disease. We will review disease mechanisms as currently understood, associated arrhythmias including conduction abnormalities, and atrial and ventricular tachyarrhythmias, guideline-directed diagnostic criteria, screening of patients with extracardiac sarcoidosis, and the use of pacemakers and defibrillators in this setting. Treatment options, including those related to heart failure, and those which may help clarify disease mechanisms are included.