Patients with myocardial infarction, particularly with a low left ventricular ejection fraction, have a high incidence of sudden cardiac death during the early months after the event. Implantable cardioverter-defibrillators are contraindicated until 40-90 days after myocardial infarction (MI). A wearable device could potentially protect against sudden death during this vulnerable period.
The Vest Prevention of Early Sudden Death Trial (VEST), a multicenter, randomized, controlled trial, investigated if patients with acute MI and an ejection fraction of 35% or less could benefit from a wearable device. 2302 participants were randomly assigned to a wearable cardioverter-defibrillator (Zoll LifeVest) plus guideline-directed therapy (1524 patients) or to guideline-directed therapy only (778).
Arrhythmic death (primary outcome at day 90) occurred in 1.6% of the patients using the device and in 2.4% of those without (relative risk, 0.67; p = 0.18). 1.3% (20) of the patients using the device received an appropriate shock and 0.6% (9) received an inappropriate shock.
In comparison to the control, the wearable device could not significantly lower the rate of arrhythmic death. However, the trial could potentially be underpowered to detect a beneficial effect due to removal of 5% of the deaths from the primary analysis (indeterminate cause or misclassification).
Author: Frederike Schmitz