Ventricular arrhythmias in patients with newly diagnosed nonischemic cardiomyopathy: Insights from the PROLONG study

Abstract

Background Patients with nonischemic cardiomyopathy (NICM) reportedly have low incidence of appropriate shocks from wearable cardioverter‐defibrillators (WCDs). A recent study questions the benefit from primary preventive implantation of implantable cardioverter‐defibrillators in NICM. We therefore analyzed a subgroup of patients with NICM from the PROLONG study. Hypothesis Patients with newly diagnosed NICM show a risk for ventricular tachyarrhythmia. Methods The PROLONG study included 167 patients with newly diagnosed heart failure and left ventricular ejection fraction (LVEF) ≤35% with a WCD. Patients with NICM were identified and included in this analysis. Results 117 patients presented with NICM. Sixty‐five (55%) were male; mean age was 51 ± 15 years. Mean LVEF at diagnosis was 23% ± 7%. Mean follow‐up was 11 ± 10 months. Mean WCD wear time was 101 ± 82 days; mean wear time per day was 21.4 ± 4.5 hours. Overall, 12 ventricular arrhythmias occurred in 10 (9%) patients (6 DCM, 4 PPCM). Nine appropriate WCD shocks for hemodynamically unstable ventricular tachycardia/fibrillation in 8 (7%) patients were observed. Two patients presented sustained hemodynamically stable ventricular tachycardia for >30 minutes detected by the WCD, but withheld WCD therapy. Conclusions Patients with newly diagnosed NICM and LVEF ≤35% show an elevated risk of ventricular tachycardia/fibrillation during initiation and optimization of heart failure therapy. To prevent sudden cardiac death, WCD should be considered in patients with newly diagnosed NICM with severely reduced LVEF.

The Wearable Cardioverter-Defibrillator: Experience in 153 Patients and a Long-Term Follow-Up

“…Several publications have also reported higher WCD shock rates in patients with newly diagnosed ICM than in patients with newly diagnosed NICM [17,26,27]. Nevertheless, there are data showing a relevant arrhythmic risk in patients with newly diagnosed NICM and non-optimized heart failure therapy [9] and there are data that also confirmed the risk of life threatening ventricular arrhythmias in the chronic phase of NICM [15]. During our long-term follow-up, 2 implanted patients with NICM received appropriate ICD therapy due to ventricular tachycardia.…”

“…Current heart failure guidelines recommend the establishment of OMT for at least 3 months before reevaluation for persistent need of ICD implantation [2]. Recent data even suggest a prolonged period of more than 3 months with OMT before ICD implantation in patients with newly diagnosed non-ischemic cardiomyopathy (NICM) and ICM due to the possibility of delayed improvement of LVEF [8,9]. In the context of acute peripartum cardiomyopathy (PPCM), as a pregnancy-associated acute myocardial dysfunction, it is assumed that about a quarter of deaths are caused by ventricular tachyarrhythmias, mostly occurring during the first 6 months [10].…”

Extended use of the wearable cardioverter-defibrillator in patients at risk for sudden cardiac death

“…Similar findings were revealed in a subsequent report from the same group, focusing on non-ischaemic cardiomyopathy patients only. 13 In the WEARIT-II Registry, we had almost 1000 subjects, and half of our patients were using the WCD for longer than 90 days. And while the majority of the patients in the WCD use >90 days subgroup had less than 6 months of WCD use duration, our study is the largest to date to report on patients with prolonged WCD use.…”

Ventrikuläre Arrhythmien bei Myokarditis und inflammatorischer Kardiomyopathie

“…In dieser Zeit kam es aber einerseits bereits in rund 7 % der Fälle zur adäquaten Therapieabgabe des tragbaren Defibrillators [44], und andererseits behieltenanhand des Kriteriums der weiterhin reduzierten LVEF < 35 %nur 37 % der Patienten eine Indikation zur permanenten ICD-Implantation [43]. Diese Daten unterstützen einerseits eine längere Evaluation der ICD-Indikation bei NICM, für die 6 Monatestatt der 3 Monate in aktuellen Leitliniensinnvoll erscheinen, und weisen andererseits darauf hin, dass der Defibrillatorweste bei diesen Patienten eine mögliche Bedeutung zukommt, die in kontrollierten Studien noch geprüft werden muss.…”