Aggregate National Experience With the Wearable Cardioverter-Defibrillator. Event Rates, Compliance, and Survival
Effectiveness of the WCD for prevention of sudden death is dependenton event type, patient compliance, and appropriate managementof ventricular tachycardia/ventricular fibrillation (VT/VF). The purpose of this study, which was published recently in the Journal of the American College of Cardiology, was to determine patient complianceand effectiveness of antiarrhythmic treatment by the wearablecardioverter-defibrillator (WCD).
Compliance and events were recorded in a nationwide registryof post-market release WCDs. Survival, using the Social SecurityDeath Index, was compared with survival in implantable cardioverter-defibrillator(ICD) patients. The results showed that of 3,569 patients wearing the WCD (age 59.3 ± 14.7 years,duration 52.6 ± 69.9 days), daily use was 19.9 ±4.7 h (>90% of the day) in 52% of patients. More days ofuse correlated with higher daily use (p < 0.001). Eightysustained VT/VF events occurred in 59 patients (1.7%). First-shocksuccess was 76 of 76 (100%) for unconscious VT/VF and 79 of80 (99%) for all VT/VF. Eight patients died after successfulconversion of unconscious VT/VF (89.5% survival of VT/VF events).Asystole occurred in 23 (17 died), pulseless electrical activityin 2, and respiratory arrest in 1 (3 died), representing 24.5%of sudden cardiac arrests. During WCD use, 3,541 of 3,569 patients(99.2%) survived overall. Survival occurred in 72 of 80 (90%)VT/VF events and 78 of 106 (73.6%) for all events. Long-termmortality was not significantly different from first ICD implantpatients but highest among patients with traditional ICD indications. From this trial the authors concluded that compliance was satisfactory with 90% wear time in >50% ofpatients and low sudden death mortality during use. Survivalwas comparable to that of ICD patients. However, asystole wasan important cause of mortality in sudden cardiac arrest events.
REFERENCE:
Mina K. Chung, MD, Steven J. Szymkiewicz, MD
, Mingyuan Shao, MS, Edwin Zishiri, MD, Mark J. Niebauer, MD, PhD, Bruce D. Lindsay, MD and Patrick J. Tchou, MD. Aggregate National Experience With the Wearable Cardioverter-Defibrillator. Event Rates, Compliance, and Survival. J Am Coll Cardiol, 2010; 56:194-203.
, Mingyuan Shao, MS, Edwin Zishiri, MD, Mark J. Niebauer, MD, PhD, Bruce D. Lindsay, MD and Patrick J. Tchou, MD. Aggregate National Experience With the Wearable Cardioverter-Defibrillator. Event Rates, Compliance, and Survival. J Am Coll Cardiol, 2010; 56:194-203.
