Two Decades After MI, Women Show Better Survival Than Men

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Despite the fact that women hospitalized for acute myocardial infarction (MI) tend to be higher risk and are slightly less likely to receive contemporary medical therapy than men, they fare better over the ensuing decades once these baseline characteristics are taken into account. The findings, from a Dutch observational study, were published online September 24, 2012, ahead of print in Circulation.

Sjoerd T. Nauta, MSc, of Erasmus Medical Center (Rotterdam, The Netherlands), and colleagues looked at 14,434 consecutive MI patients admitted to their institution between June 1985 and December 2008. Slightly more than a quarter of the patients were women (28%; n = 4,028).

On average, women were 5 years older than men, and age at presentation increased uniformly for both sexes. Women were more likely to have hypertension, diabetes, renal dysfunction, or anemia, and were less likely have a history of smoking, MI, PCI, CABG, or STEMI.

Women Come Out Ahead

During the study period, 1,544 women and 3,708 men died. Mortality was higher in women than in men both at 30 days (7% vs. 6%; OR 1.3; 95% CI 1.1-1.5; P = 0.002) and at 20 years (71% vs. 65%; HR 1.1; 95% CI 1.0-1.2).

But adjustment for a wide range of potential confounders including age, comorbidities, and decade of treatment changed the equation. Women and men were equally likely to die at 30 days (adjusted OR 1.0; 95% CI 0.85-1.2). By 20 years, however, women had lower mortality than men (adjusted HR 0.77; 95% CI 0.66-0.90).

Overall, women were as likely as men to receive both thrombolytic therapy (22% vs. 24%; P = 0.13) and PCI (53% vs. 53%; P = 0.80) as well as aspirin (67% vs. 68%; P = 0.39), but they were less likely than men to receive statins (70% vs. 73%; P < 0.01) or beta-blockers (56% vs. 59%; P < 0.001).

Temporal mortality reductions over the study period were at least as high in women compared with men in both the short and long term. For example, women hospitalized for MI from 2006 to 2008 had 83% lower mortality than those treated in 1985 to 1987. Men saw a 73% reduction during the same time frame (P for interaction = 0.30).

Long-Term Data Bolster Previous Research

Because women on average presented with a higher risk profile, Mr. Nauta and colleagues suggest that “it is unlikely that other differences between women and men, including differences in biological factors and in treatment, caused the higher unadjusted mortality rate in women.”

They focus on the “unique” long-term nature of the study, which confirms prior research showing that women are at a lower risk for death up to a year after MI. The new data extend this finding up to the 20-year mark.

Still, the findings “might demonstrate a best case scenario,” the authors write, because “gender disparities in medical management were limited. This might have contributed to relatively favorable outcomes in women, compared to studies in countries where women less often receive evidence based management.”

Lastly, they point out that the substantial temporal improvements in short- and long-term mortality over time “suggest that both men and women will benefit from further improvements in care for acute myocardial infarction.”

Individualized Management Awaits

In an e-mail communication, Sunil V. Rao, MD, of Duke University Medical Center (Durham, NC), told TCTMD that “it is somewhat surprising and reassuring that women are doing just as well as men with respect to receiving evidence-based therapies. In addition, it is also reassuring that their outcomes are equitable after adjusting for baseline risk.”

In ACS patients, a uniform approach to care is vital to treatment success, he said, and the study “really underscores the importance of having clinical pathways and protocols. . . . It shows that such a strategy can, in fact, provide equal care across patient subgroups.”

Going forward, the challenge lies with individualized management, Dr. Rao continued, noting that, “In addition, we need to understand not just sex disparities, but also race and socioeconomic disparities.” The results also need to be confirmed in a multi-institutional, international setting, he added.

“Moreover, we need to understand why the females who present with ACS have higher risk features,” he said, suggesting that women might receive less primary prevention. “Finally, we need to understand sex differences in response to therapy as it relates to safety. For example, we know that women are at higher risk for bleeding from antithrombotic drugs. Why is that? What can we do about it?”

 

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Source:
Nauta ST, Deckers JW, van Domburg RT, et al. Gender-related trends in mortality in hospitalized men and women after myocardial infarction between 1985 and 2008: Equal benefit for women and men. Circulation. 2012;Epub ahead of print.

 

 

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