Approximately 40,000 young women are hospitalized in the United States (US) annually due to acute myocardial infarction (MI). Young women who are hospitalized for MI are twice as likely to die in hospital as young men. Approximately 8000 deaths of women aged ≤55 years occur due to heart disease in the US annually.
The observational VIRGO study (NCT00597922) examined gender differences in 1-year post-acute MI outcomes in patients aged between 18 to 55 years. Study protocol dictated a 2:1 enrollment ratio of women to men; the final cohort included 2007 women and 972 men. VIRGO analyzed the outcomes of these 2979 patients, all of whom had experienced AMI across 103 hospitals in the US.
Researchers calculated incidence rates ([IRs] per 1,000 person-years) and IR ratios with 95% confidence intervals (CIs) to compare sex differences in all-cause and cause-specific hospitalizations. They also performed sequential modeling to evaluate the sex difference by calculating subdistribution HRs (SHRs) accounting for deaths.
Rehospitalization rates higher in women
At least one rehospitalization, most frequently for cardiac reasons, occurred in 905 (30.4%) of patients in the year subsequent to discharge. Hospitalization for coronary concerns occurred more commonly in women (IR 171.8, 95%CI: 153.6-192.20) than in men (IR 117.8, 95%CI: 97.3-142.6). The IR for noncardiac hospitalization was 145.8 (95%CI: 129.2-164.5) among women, and 69.6 (95%CI: 54.5-88.9) among men. Researchers also noted a sex difference for coronary-related hospitalizations: (SHR: 1.33; 95%CI: 1.04-1.70; P=0.02) and noncardiac hospitalizations (SHR: 1.51; 95%CI: 1.13-2.07; P=0.01).
VIRGO demonstrated that women with AMI experience more adverse outcomes than men, both immediately and in the first year thereafter. While hospitalization for cardiac causes occurred most frequently, noncardiac hospitalizations showed the most significant sex disparity. Inflammation, metabolic abnormalities, sex hormones, and genetics may reflect a predisposition to, and poor recovery from, heart disease. VIRGO results made it clear that more research is needed to understand heart disease in women.
Author: Kelly Schoonderwoerd
Original Article: Sawano et al. JACC 2023;81(18):1797-1806.