Younger Women vs Men Have Worse Outcomes Following AMI

Significant outcome differences were seen between younger women and younger men who had a heart attack between ages 18 and 55 years, with coronary-related and noncardiac hospitalization rates demonstrating the greatest sex-specific disparities, according to study findings published today in Journal of the American College of Cardiology.¹

“Younger women experience worse health status than men after their index episode of acute myocardial infarction (AMI),” the study authors wrote. “However, whether women have a higher risk for cardiovascular and noncardiovascular hospitalizations in the year after discharge is unknown.”

Their study was a subanalysis of data from the VIRGO study and it encompassed 2979 patients (N = 2007 women and 972 men) who had a heart attack between ages 15 and 55 years at 103 hospitals within the United States from August 2008 through January 2012; outcomes evaluated included all-cause and cause-specific acute events requiring hospitalization in the year after discharge for an AMI. Incidence rates were calculated per 1000 person-years, and women were enrolled at a 2:1 ratio.

Coronary reasons comprised the top cause of hospitalizations in the year after a heart attack–related hospitalization, but these were still 31.4% lower among men (incidence rate [IR], 117.8; 95% CI, 97.3-142.6) compared with women (IR, 171.8; 95% CI, 153.6-192.2). Noncardiac-related hospitalizations were lower, too, by 52.3%, among men (IR, 69.6; 95% CI, 54.5-88.9) vs women (IR, 145.8; 95% CI, 129.2-164.5).

Overall, the study investigators found sex-specific differences in coronary-related and non­–cardiac-related hospitalizations between the 2 groups of patients. Women had 33% (HR, 1.33; 95% CI, 1.04-1.70; P = .02) and 51% (HR, 1.51; 95% CI, 1.13-2.07; P = .01) higher risks, respectively, compared with men.

The mean (SD) overall patient age was 47.1 (6.2) years, and the self-reported ethnicities were non-Hispanic Asian or Pacific Islander (1.5%), non-Hispanic American Indian or Alaska Native (2.5%), Hispanic or Latino (7.9%), non-Hispanic Black (17.5%), and non-Hispanic White (70.0%). Median (IQR) follow-up was 365 (223-365) days.

Also among the women participating compared with the men, there were higher rates of obesity (55.2% vs 47.7%), hypertension (67.1% vs 64.5%), diabetes (39.8% vs 26.6%), chronic obstructive pulmonary disease (14.2% vs 6.4%), congestive heart failure (5.7% vs 2.3%), stroke (4.1% vs 1.9%, renal disease (12.7% vs 8.6%), and physical inactivity (37.4% vs 31.2%). At baseline, more women were considered to have low income vs men (47.6% vs 31.4%) and had a history of depression (48.7% vs 24.2%).

When presenting to the hospital, women also were less likely to report chest pain (86.3% vs 89.2%) but more likely to report more than 6 hours after symptom onset (47.6% vs 38.0%). They also more likely to have non–ST-elevated MI presentation (54.2% vs 42.1%) and MI with nonobstructive coronary arteries (12.8% vs 2.9%).

Upon discharge, women were shown to have a longer length of stay and to have received fewer guideline-recommended therapies:

• Aspirin: 92.6% vs 95.0%
• Statins: 67.5% vs 71.7%
• Beta-blockers: 89.6% vs 94.1%
• Angiotensin-converting enzyme inhibitors/angiotensin receptor blockers: 61.2% vs 70.6%

When hospitalization was seen in the year after initial discharge, women had significantly higher incident rate ratios (IRRs) vs men for coronary-related events (IRR, 1.46; 95% CI, 1.16-1.84; P < .001) and noncardiac/stroke events (IRR, 2.10; 95% CI, 1.59-2.80; P < .001).

“Of note, the timing of hospitalizations and invasive procedures performed during the hospitalizations did not greatly differ between sexes,” the authors wrote. “The age adjusted Kaplan-Meier survival curves showed that all-cause hospitalizations and coronary-related and noncardiac hospitalizations peaked in the first month after discharge and gradually declined to reach a steady state 3 months after discharge for both sexes.”

The authors underscored that the sex disparity for coronary-related hospitalization was attenuated by considering psychosocial factors. In addition, the difference in noncardiac hospitalization also was attenuated, but by considering patient demographics, comorbidities, and psychosocial factors. For both of these outcomes, adding AMI presentation and predischarge treatment variables had close to no effect on outcomes.

When speaking to how their findings add to the existing literature, the investigators highlighted that their analysis is the first comprehensive analysis of sex differences in the 1-year incidence of clinically important cardiovascular events, that reports on specific causes of hospitalizations are limited among patients who experience AMI at a young age, and that they found a consistently higher risk for coronary-related and noncardiac hospitalizations among young women.

“Future research should develop and test strategies, which may include intensification of postdischarge management through in-person or virtual sessions to improve health literacy, patient motivation, and addressing socioeconomic barriers to reach satisfactory levels of adherence to evidence-based secondary prevention strategies,” the authors concluded.

Additional studies are also warranted that target noncardiovascular hospitalizations and postdischarge care, according to an accompanying editorial.² These should focus on medication adherence, outpatient visit attendance, referral and participation in cardiac rehabilitation, and the impact of social determinants of health on any of those factors.

References

1. Sawano M, Lu Y, Caraballo C, et al. Sex difference in outcomes of acute myocardial infarction in young patients. J Am Coll Cardiol. Published online May 1, 2023. doi:10.1016/j.jacc.2023.03.383

2. Gulati M, Holtzman JN, Kaur G. Increased rehospitalization in young women with acute myocardial infarction at 1 year: adding insult to infarct. J Am Coll Cardiol. Published online May 1, 2023. doi:10.1016/j.jacc.2023.03.394