Study Identifies Disparities in Survival After Acute MI
Patients who are black or female tend to lose more years of life following acute MI compared with those who are white or male, according to a study published in the August 11, 2015, issue of the Journal of the American College of Cardiology. The race-related difference may be due to disparities in preventive care and long-term treatment, but the sex-based discrepancy remains unexplained, the paper reports.
Researchers led by Harlan M. Krumholz, MD, SM, of Yale-New Haven Hospital (New Haven, CT), looked at data on 146,743 fee-for-service Medicare beneficiaries (mean age 75.9 years) who were hospitalized for acute MI between 1994 and 1995 and included in the Cooperative Cardiovascular Project. Analysis was restricted to patients aged 65 to 90 years, and they were stratified by race (93.6% white; 6.4% black) and sex (51.9% men; 48.1% women).
At baseline, white women and black patients of both sexes had higher rates of diabetes, hypertension, and heart failure compared with white men. Black men had the highest rate of current smoking, and white men were most likely to have a history of acute MI, CABG, or PCI
Survival at 17 years was 8.3% for white men, 6.4% for white women, 5.4% for black men, and 5.8% for black women. Women lost an average of 1.86 more years of potential life after an acute MI than did men, with the discrepancy between sexes greatest at younger ages. Similarly, black patients lost an average of 0.86 more years of potential life compared with white patients.
The findings were similar when looking at the percentage of potential life lost, with women losing more of their lifespan than men and black patients losing more than their white counterparts. The loss of remaining life was greatest for black women. Adjustment for demographics, medical history, clinical presentation, and treatment type reduced the disadvantage of women relative men and reversed the racial difference, meaning that black patients stood to lose less life than their white peers (table 1).
“Although we would expect women to live longer than men after [acute MI] because of their life expectancy in the general population, [acute MI] appears to act as an equalizer by negating women’s survival advantage,” the authors write.
Due to the reversal of race-related disparity in survival upon adjustment, the authors posit that black patients suffered relatively more loss of expected lifespan due to “poorer clinical presentation and lower treatment rates,” as the black cohort was more likely to have diabetes, hypertension, and heart failure upon hospitalization and less likely to receive revascularization within 30 days.
Addressing Disparity at Both the Patient, Policy Levels
Study coauthor Emily M. Bucholz, MD, PhD, MPH, of Boston Children’s Hospital (Boston, MA), told TCTMD in an email that the results “would suggest that black patients have poorer outcomes after heart attack because of deficits in both preventive and post–heart attack care. These are very tangible points of intervention.”
Given that the researchers could not pinpoint the source of the sex-based difference, however, Dr. Bucholz added that these findings “show that from a higher policy level, there is significantly more work that needs to be done both in reducing racial disparities in healthcare but also in understanding why women are at higher risk after [acute MI] than men.” She suggested that “it may be that women have poorer follow-up after heart attack or don’t receive as many recommended therapies over the long term, which may contribute to their risk of death.”
The authors caution that “because the quality of care for patients with acute MI has improved since the mid-1990s and patients are living longer today, the life expectancy estimates reported in this paper may not accurately reflect those of patients today.”
Nonetheless, relative life-years lost may be a preferred metric of patient outcome. “In this study, we showed how traditional mortality rates can be misleading,” said Dr. Bucholz. “Whereas men and women had similar long-term mortality rates after heart attack, women lost significantly more years of life than men after heart attack because they live longer in the general population. Therefore, women actually do appear to be at a significant survival disadvantage relative to men, but you need to calculate life-years lost to show this difference.”
Source:Bucholz EM, Normand S-LT, Wang Y, et al. Life expectancy and years of potential life lost after acute myocardial infarction by sex and race: a cohort-based study of Medicare beneficiaries. J Am Coll Cardiol. 2015;66:645-655.
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*Nicole Lou is the 2015 Recipient of the Jason Kahn Fellowship in Medical Journalism
- Dr. Krumholz reports receiving institutional research support from Johnson & Johnson and Medtronic, working under contract with the Centers for Medicare & Medicaid Services, and serving as chair of the Cardiac Scientific Advisory Board for United Health.
- Dr. Bucholz reports no relevant conflicts of interest.