1Kath. Klinikum Bochum Kardiologie und Rhytmologie Bochum, Deutschland; 2Berufsgenossenschaftliches Universitätsklinikum Bergmannsheil Medizinische Klinik II, Kardiologie und Angiologie Bochum, Deutschland; 3Department of Cardiology University Heart Center, University Hospital Zurich Zurich, Schweiz; 4Department of Cardiology, Angiology, Haemostaseology and Medical Intensive Care University Medical Center Mannheim, Medical Faculty Mannheim Mannheim, Deutschland; 5HELIOS Klinikum Krefeld Medizinische Klinik I Krefeld, Deutschland; 6Klinikum Sankt Georg Klinik für Kardiologie, Angiologie und intern. Intensivmedizin Leipzig, Deutschland; 7Universitätsklinikum Bonn Medizinische Klinik und Poliklinik II Bonn, Deutschland; 8Universitätsklinikum Mannheim I. Medizinische Klinik Mannheim, Deutschland; 9Kath. Klinikum Bochum Cellular Physiology Bochum, Deutschland; 10Universitätsklinikum Frankfurt Med. Klinik III - Kardiologie, Angiologie Frankfurt am Main, Deutschland; 11Marienhospital Gelsenkirchen GmbH Klinik für Kardiologie, Angiologie und Interne Intensivmedizin Gelsenkirchen, Deutschland; 12Klinikum Saarbrücken gGmbH Medizinische Klinik II Saarbrücken, Deutschland; 13Klinikum der Ruhr-Universität Bochum Medizinische Klinik II, Kardiologie Bochum, Deutschland; 14Berufsgenossenschaftlliches Universitätsklinikum Bergmannsheil Medizinische Klinik II, Kardiologie und Angiologie Bochum, Deutschland
Background: Wearable cardioverter defibrillator (WCD) can protect patients from sudden cardiac death due to ventricular tachyarrhythmia and serve as a bridge to decision of definite defibrillator implantation. The aim of this analysis from an international, multicentre WCD registry was to identify predictors of sustained ventricular arrhythmia in this population.
Methods and Results: In total, 1675 consecutive patients with WCD were included in a multicenter registry from 9 European centres, with a median follow-up of 440 days (IQR 120-893). The primary study end point was the occurrence of sustained ventricular tachyarrhythmia (sustained ventricular tachycardia and ventricular fibrillation). Mean age of the WCD cohort was 59.3 years, and 79% of patients were male. Mean baseline left ventricular ejection fraction was 30% and increased to 42.6% at follow-up after 6-12 months. Sustained ventricular tachycardia was detected by WCD in 5.4% and ventricular fibrillation in 0.9% of all patients. Of the 507 patients (30.3%) receiving ICD-implantation during follow-up, sustained ventricular tachycardia was recorded in 47 patients (9.3%) and ventricular fibrillation in 13 patients (2.6%).
Non-ischemic cardiomyopathy (HR 0.6, 95% CI 0.4-0.9, p=0.011), left ventricular ejection fraction improvement in the first three months (HR 0.6, 95% CI 0.4-0.9, p=0.022), angiotensin-converting-enzyme-inhibitor use (HR 0.6, 95% CI 0.4-0.9, p=0.021) and aldosterone antagonist use (HR 0.7, 95% CI 0.5-1.0, p=0.034) were associated with a significantly lower risk of sustained ventricular tachyarrhythmia during follow-up. In contrast, atrial fibrillation and atrial flutter increased the risk (HR 1.9, 95% CI 1.0-3.4, p=0.031).
Conclusions: Patients who received WCD due to a transient increased risk of sudden cardiac death have a comparatively lower risk of sustained ventricular arrhythmias in the presence of non-ischemic cardiomyopathy and freedom from atrial fibrillation and atrial flutter. Of note, optimal medical treatment for heart failure not only results in an improvement in left ventricular ejection fraction but also in a reduction in the risk for sustained ventricular tachyarrhythmia.
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Table 1: Baseline characteristics of the cohort | |
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Variables |
n = 1675 |
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Demographics |
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Male, n (%) |
1326/1675 (79.2) |
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Age, mean±SD |
59.3±14.8 |
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Comorbidities |
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Coronary artery disease, n (%) |
466/967 (48.2) |
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Myocardial infarction, n (%) |
348/1078 (32.3) |
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Atrial fibrillation or atrial flutter, n (%) |
391/1398 (28) |
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Drug treatment |
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ACE Inhibitors, n (%) |
811/1157 (70.1) |
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Aldosterone antagonist, n (%) |
754/1158 (65.1) |
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ß Blocker, n (%) |
1440/1550 (92.9) |
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LVEF |
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LVEF at index, mean±SD |
30±11.9 |
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LVEF after 6-12 months, mean±SD |
42.6±12.5 |
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EF Improvement > 35%, n (%) |
1009/1488 (67.8) |
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SD, Standard deviation; LVEF, left ventricular ejection fraction; ACE, Angiotensin-converting-enzyme | |
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Table 2: Follow-up data | |
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Variables |
n = 1675 |
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Recorded WCD Data |
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Wear days, mean±SD |
65.1±45.9 |
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Average wear hours, mean±SD |
21.2±4.4 |
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Arrhythmic episodes during WCD therapy |
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Sustained ventricular tachycardia, n (%) |
90/1669 (5.4) |
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Ventricular fibrillation, n (%) |
15/1667 (0.9) |
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WCD shocks |
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Appropriate, n (%) |
44/1670 (2.6) |
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Inappropriate, n (%) |
4/1670 (0.2) |
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CIED | |
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Device implantation, n (%) |
507/1612 (31.5) |
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Arrhythmic episodes post-CIED implantation | |
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Sustained ventricular tachycardia, n (%) |
47/359 (13.1) |
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Ventricular fibrillation, n (%) |
13/359 (3.6) |
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CIED, cardiac implantable electronic device; WCD, wearable cardioverter defibrillator | |