176-43: Usefulness and Potential Role of the Wearable Cardioverter-Defibrillator in Acute Phase Care of Patients at High Risk of Sudden Cardiac Death: A Single-Center Japanese Experience

Background: The Wearable cardioverter-defibrillator (WCD; Life Vest 4000, Zoll, PA, USA) has been expected to play a role as a safe and effective bridge therapy to implantable cardioverter-defibrillator (ICD) implantation in patients at high risk of sudden cardiac death (SCD), mainly in outpatient setting. Although WCD has been available in Japan since April 2014, its clinical use is still limited and usefulness of WCD is unclear. Methods: During the early period after hospitalization, 50 consecutive patients (median age 56, 46 men, 38 in secondary prevention) at high risk of SCD were prescribed WCD. We analyzed usefulness and potential roles of WCD. Results: Of the 50 patients, 39 patients used WCD only during hospitalization. During WCD use [median 16 (IQR 8–30) days], all patients wore WCD for 98% of a day regardless of in or out of hospital use. Sustained ventricular tachycardia (VT) was detected in 4 patients (8%; primary prevention in 1) with 7 episodes, and 6 of 7 episodes required shock therapy. Of 6 shock-required episodes, 4 episodes were therapy for sustained VT and the other 2 episodes were therapy for VF. The median rate of VT was 236 (IQR 203–250) bpm. None of them died of VA during WCD use. Only 25 patients (56%) underwent ICD implantation following WCD use, because of reduced risk of SCD after optimal pharmacological therapy or improvement of the left ventricular function, and re-evaluation of necessity of ICD therapy during WCD use. Conclusions: By using WCD for acute phase care of patients at high risk of SCD, satisfactory patient compliance and survival were achieved. Furthermore, WCD was useful for reduction of unnecessary implantation of ICD, and it could be beneficial from the medical economic point of view.