Women hospitalized for a heart attack are less likely to receive treatment and more likely to die than men

The likelihood of hospitalization for, treatment of, and death by heart attack is not the same for men and women in a large-scale study of six countries, including the United States. Men were more likely to be hospitalized with a heart attack, while hospitalized women were less likely to receive treatment and more likely to die from severe heart attack. Findings from the NIA-funded study were published in Circulation: Cardiovascular Quality and Outcomes.

There are two types of acute myocardial infarction, or heart attack. An ST-segment elevation myocardial infarction (STEMI) creates a longer interruption to the heart's blood supply, whereas a non-ST-segment elevation myocardial infarction (NSTEMI) creates some loss of blood supply and a less severe form of heart attack than STEMI. Both are medical emergencies that require hospitalization and treatment and may result in death. Treatments include cardiac catheterization, percutaneous coronary intervention (PCI), and coronary artery bypass grafting (CABG).

Researchers from the University of Texas; Harvard Medical School; University of Manitoba, Canada; and other collaborative institutions examined whether sex differences in older adults hospitalized for a heart attack were consistent across countries with advanced health systems. Using administrative data from the International Health Systems Research Collaborative, they identified more than 1.5 million adults age 66 years and older who had been hospitalized with a primary diagnosis of STEMI or NSTEMI between 2011 and 2018 in the U.S., Canada, England, Netherlands, Taiwan, and Israel. The researchers looked at hospitalization, treatment, and mortality data in each country, comparing women and men.

Hospitalizations for heart attacks decreased in all countries from 2011 to 2018, with a steeper decline observed among women compared to men. While fewer than half of patients hospitalized were women across nearly all countries and years studied, the proportion was highest in the U.S. for both STEMI (47.5% in 2011 and 42% in 2018) and for NSTEMI (50.7% and 46.9%). The researchers also found the hospitalized women were less likely than men to receive crucial treatments - cardiac catheterization, PCI, CABG - and had higher rates of death for STEMI than men in most countries but lower rates of death for NSTEMI.

Further investigation into what factors may be contributing to these sex disparities could point to pathways for intervention. Limitations of the current study include use of administrative data, which lacks detailed clinical information, and counting only inpatient treatment, which may underestimate rates of catheterization and PCI in locations where outpatient treatment is common.

This research was supported in part by NIA grant R01AG058878.

Reference: Lu H, et al. Sex-based disparities in acute myocardial infarction treatment patterns and outcomes in older adults hospitalized across 6 high-income countries: An analysis from the International Health Systems Research Collaborative. Circulation: Cardiovascular Quality and Outcomes. 2024. Epub Feb. 8. doi: 10.1161/CIRCOUTCOMES.123.010144.