Women with heart attacks are less likely to receive crucial therapies and have higher mortality than men

Toronto, ON, February 8, 2024 – Between 2011 and 2018 heart attack patients were increasingly men across six diverse countries, yet women in all countries were less likely to receive important cardiac treatments and were more likely to die, according to a new study from ICES, the University of Texas Medical Branch, Galveston and Harvard University.

The researchers say that the findings suggest there are sex-based disparities present in countries with very different healthcare systems and cultures, which raises questions about why women receive differential treatment.

“Though our findings showed that heart attacks are increasingly male and less likely female, there were concerning gaps in care that affected women more,” says senior author Peter Cram, an adjunct scientist at ICES and The University of Texas Medical Branch, Galveston. “All countries, including Canada, need to address these issues and improve healthcare delivery for older patients who experience severe heart attacks.”

The authors analyzed medical records of adults 66 years or older who were hospitalized for at least one day with a type of heart attack known as ST-elevation myocardial infarction (STEMI, which tends to be more severe) and non-ST-elevation myocardial infarction (NSTEMI). Outcomes for STEMI and NSTEMI male patients were compared with outcomes among female patients in the US, Canada (Ontario and Manitoba), England, Netherlands, Taiwan, and Israel between 2011 and 2018.

Published in the journal Circulation, Cardiovascular Quality and Outcomes, the study included 1.5 million older adults, and cohort sizes ranged between countries.

Findings showed that:

• In Canada between 2011-2018, rates of STEMI decreased by 14 per cent for males and 16 per cent for females. For NSTEMI, rates decreased by 18 per cent for males and 20 per cent for females.
• Women hospitalized with both types of heart attacks were less likely than men to receive important cardiac treatments, including cardiac catheterization, percutaneous coronary intervention, and coronary artery bypass grafting (CABG) in all six countries in both 2011 and 2018, with one exception (CABG in Taiwan in 2018).
• In 2018, mortality after a more severe heart attack (STEMI) was higher for females than males in five countries (US, Canada, Netherlands, Israel, Taiwan) but lower for females than males for less severe heart attacks (NSTEMI).

“We really need interventions beyond what is currently available to monitor and address health disparities between men and women, as well as in other traditionally underserved groups,” says co-author Dr. Dennis Ko, a senior scientist at ICES and director of the Schulich Heart Research Program at Sunnybrook Research Institute.

As the study focused on older adults, it is unclear if these findings apply to younger men and younger women hospitalized with heart attacks.

“Our study suggests that sex-based disparities are both persistent and widespread and transcend geopolitical borders,” adds Dr. Cram. “Our finding that these disparities exist in countries with diverse cultures, populations, and health systems raise important questions what is causing this male-female gap.  Potential causes including misdiagnosis, bias, biological differences, and social determinants of health all warrant consideration.”

The study “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” was published in Cardiovascular Quality and Outcomes.

Authors: Lu H, Hatfield L, Al-Azazi S, Bakx P, Banerjee A, Burrack N, Chen YC, Fu C, Gordon M, Heine R, Huang N, Ko D, Lix L, Novack V, Pasea L, Qiu F, Stukel T, Uyl-de Groot C, Weinreb G, Landon B, Cram P.

ICES is an independent, non-profit research institute that uses population-based health information to produce knowledge on a broad range of healthcare issues. Our unbiased evidence provides measures of health system performance, a clearer understanding of the shifting healthcare needs of Ontarians, and a stimulus for discussion of practical solutions to optimize scarce resources. ICES knowledge is highly regarded in Canada and abroad and is widely used by government, hospitals, planners, and practitioners to make decisions about care delivery and to develop policy. For the latest ICES news, follow us on X: @ICESOntario

ABOUT THE UNIVERSITY OF TEXAS MEDICAL BRANCH: Texas’ first academic health center opened its doors in 1891 and today has four campuses, five health sciences schools, six institutes for advanced study, a research enterprise that includes one of only two national laboratories dedicated to the safe study of infectious threats to human health, a Level 1 Trauma Center and a health system offering a full range of primary and specialized medical services throughout the Texas Gulf Coast region. UTMB is an institution in the University of Texas System and a member of the Texas Medical Center.

FOR FURTHER INFORMATION PLEASE CONTACT:

Misty Pratt
Senior Communications Officer, ICES
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