Utility of the Wearable Cardioverter-Defibrillator in Patients With Newly Diagnosed Cardiomyopathy

• Published in: Journal of the American College of Cardiology 2015-12, Vol.66 (23), p.2607-2613
• Main Authors: Singh, Madhurmeet, DO, Wang, Norman C., MD, MS, Jain, Sandeep, MD, Voigt, Andrew H., MD, Saba, Samir, MD, Adelstein, Evan C., MD
• Format: Article
• Language: English
• Subjects: Cardiac arrhythmia; Cardiology; Cardiomyopathy; Cardiovascular; Colleges & universities; Compliance; Coronary vessels; FDA approval; Heart attacks; Internal Medicine; Medical records; sudden cardiac death; Veins & arteries; ventricular tachycardia; ventricular fibrillation; Waiting period
• ISSN: 0735-1097; 1558-3597
• DOI: 10.1016/j.jacc.2015.09.079

Abstract Background The wearable cardioverter-defibrillator (WCD) has emerged as a means of protecting patients with newly diagnosed nonischemic cardiomyopathy (NICM) or ischemic cardiomyopathy (ICM) against sudden cardiac death while awaiting re-evaluation of cardiac function. Objectives This study sought to characterize the risk of appropriate WCD therapy in newly diagnosed NICM and ICM patients according to cardiomyopathy etiology in an independent study. Methods Medical records of all patients prescribed a WCD between June 2004 and May 2015 at our institution (n = 639) were analyzed, focusing on 254 patients with newly diagnosed NICM and 271 patients with newly diagnosed ICM. Patients with a prior implantable cardioverter-defibrillator or sustained ventricular arrhythmias were excluded (n = 114). The primary endpoint was appropriate WCD therapy. Results Median WCD wear time was 61 days (interquartile range [IQR]: 25 to 102 days) per patient and 22 h/day (IQR: 17 to 23 h/day). During 56.7 patient-years, 0 NICM patients received an appropriate WCD shock, whereas 3 (1.2%) received an inappropriate shock. During 46.7 patient-years, 6 (2.2%) ICM patients received an appropriate shock; 5 survived the episode, and 4 survived to hospital discharge. All 6 patients with an appropriate shock were male with QRS duration >120 ms. Two (0.7%) ICM patients received an inappropriate shock. Conclusions In this independent, retrospective study, the risk of appropriate WCD therapies in patients with newly diagnosed NICM was minimal. Routine use of the WCD in this population should be prospectively evaluated. The risk of appropriate therapies in newly diagnosed ICM was comparable to that observed in prior observational studies.