The following is the summary of “Risk Factors for Arrhythmic Death, Overall Mortality, and Ventricular Tachyarrhythmias Requiring Shock After Myocardial Infarction” published in the January 2023 issue of Cardiovascular Disease by Lai, et al.

In the post-myocardial infarction (post-MI) period, the VEST (Vest Prevention of Early Sudden Death Trial) found a tendency toward decreased sudden death and lower overall mortality using a wearable cardioverter-defibrillator (WCD). It is, however, not entirely obvious which patients might benefit most from WCD treatment. To determine which patients would gain the most from a WCD, researchers looked for predictors of arrhythmic death, overall mortality, and ventricular tachyarrhythmias needing an adequate shock. Patients with an ejection fraction of ≤35% or lower were enrolled in the VEST study to treat acute MI. In addition, 7 risk factors were examined using logistic regression to determine their connection with arrhythmic death, overall mortality, and adequate shock. 

There were 44 cases of arrhythmic death (1.9%) and 86 total deaths (3.7%) among the study’s 2,302. 20 of the 1,524 people randomly assigned to WCD experienced an acceptable shock (1.3%). Having a greater heart rate at discharge (odds ratio [OR] 1.19 per 10 beats/min) and lower systolic blood pressure (SBP); odds ratio [OR] 1.64 per 10 mm Hg) were also linked with arrhythmic mortality in multivariable analysis. The odds of dying from any cause increased with a lower SBP (OR 1.37), while it decreased with a greater heart rate (OR 1.10). The correct shock was associated with a higher heart rate (OR 1.20). Patients with an SBP ≤100 and a heart rate  ≥100 had an elevated risk of arrhythmic death (OR 4.82), overall mortality (OR 3.10), and appropriate shock (OR 1). (OR 6.13). 

Lower SBP and greater heart rate at discharge were highly linked with arrhythmic death and all-cause mortality in patients with acute MI and reduced ejection fraction. In conclusion, the presence of these risk variables identifies a subset of individuals at elevated risk for adverse outcomes in a context where WCD therapy is warranted.