A wearable cardioverter–defibrillator did not reduce arrhythmic death in MI with reduced ejection fraction
- Sullivan, Kristen MD
- Van Spall, Harriette G.C. MD, MPH, FRCPC
Question
In patients who have a myocardial infarction (MI) and a reduced ejection fraction (EF), does using a wearable cardioverter–defibrillator (WCD) shortly after MI reduce risk for arrhythmic death?
Methods
Design: Randomized controlled trial (RCT) (Vest Prevention of Early Sudden Death Trial [VEST]). ClinicalTrials.gov NCT01446965.
Allocation: Unclear allocation concealment.
Blinding: Blinded (outcome adjudicators).
Follow-up period: Mean 84 days.
Setting: 108 clinical centers in the USA, Poland, Germany, and Hungary.
Patients: 2348 adults ≥ 18 years of age (mean age 61 y, 73% men) who were hospitalized with acute MI, had an EF ≤ 35% (assessed ≥ 8 h after the MI if no revascularization or if the patient had percutaneous coronary intervention, or ≥ 48 h if the patient had coronary artery bypass grafting), and were within 7 days of discharge. Exclusion criteria included current implantable cardioverter–defibrillator (ICD) or unipolar pacemaker, clinically important valve disease, long-term hemodialysis, indication for an ICD, chest circumference that would not accommodate the WCD, or discharge to a nursing facility with expected stay > 7 days.
Intervention: WCD plus guideline-directed (“usual”) care (n = 1554) or usual care alone (n = 794) (2:1 allocation). Patients in the WCD group were fitted with the Zoll LifeVest WCD, trained in its use, and instructed to wear the device for 3 months except while bathing.
Outcomes: Arrhythmic death (sudden death or nonsudden death due to ventricular tachyarrhythmia) at 90 days. Secondary outcomes included all-cause mortality and adverse events. Due to slow recruitment and lower-than-expected WCD wear time, the original primary outcome of all-cause mortality at 60 days was changed to arrhythmic death at 90 days and the sample size was changed to 2300 patients, which provided 70% power to detect a between-group difference.
Patient follow-up: 97% (intention-to-treat analysis).
Main results
The main efficacy results are in the Table. 1.4% of patients in the WCD group received ≥ 1 appropriate shock, and 0.6% received ≥ 1 inappropriate shock. 12 of the 48 patients in the WCD group who died were wearing the device at the time. Patients in the WCD group were more likely to report rashes (15.3% vs 7.1%, P < 0.001) and less likely to report shortness of breath (39% vs 45%, P = 0.004) than were patients in the usual-care group.
Conclusion
In patients who have a myocardial infarction and a reduced ejection fraction, using a wearable cardioverter–defibrillator shortly after MI did not reduce risk for arrhythmic death.
