STEMI Mortality Risk Doubled in Women, Even in North America, Europe

A global analysis combining data from 27 countries suggests that women hospitalized with STEMI are twice as likely to die as men. Strikingly, the higher mortality was seen even in countries with the best STEMI care in the world, and was seen both in-hospital and during follow-up, suggesting that even when women get optimal treatment, their chances of survival remain lower than men’s.

Ido Haimi, a medical student at Yale University School of Medicine (New Haven, CT), presented the analysis here at CRT 2016.

Speaking with TCTMD, Haimi lamented the profound dearth of data tracking hospital admissions and outcomes for women with STEMI. 

He pointed to the VIRGO study, which showed excess mortality in women, even in women younger than 55 years old. “There is no reason in the universe why women should have a higher mortality rate with STEMI, when we know that outcomes after PCI are similar in men and women,” he said. “This made us say, let’s scratch the surface and see if there’s anything there.”

In a preliminary analysis, Haimi and colleagues, including senior author Alexandra Lansky, MD, Yale School of Medicine, conducted a retrospective analysis of data from 13 countries representing 8 different global regions. Among 410,000 admitted for STEMI between 2005 and 2015, only 26% were women.

“The first thing that was screaming at us was that mortality rates are immensely higher across the entire world”—more than a 2-fold increase in 30-day mortality for women in the preliminary analysis, Haimi said. That prompted investigators to go back to the literature and extract any studies looking at gender disparities and STEMI from 2000 onwards. Ultimately, they pulled together 75 studies, including 731,213 patients, from 27 countries grouped by 6 different geographic regions. 

Here again, the proportion of women represented in the studies was just 32%.

“So either we don’t document what’s going on in women, which is a big problem, or women with STEMI are not coming to hospital,” Haimi said. “So whichever one you choose, it’s like, pick your poison.”

Women presenting with STEMI had important baseline differences: they tended to be older, with a higher prevalence of hypertension and diabetes, but they were less likely to be active smokers or have a history of prior myocardial infarction. The higher prevalence of diabetes is particularly striking, Haimi noted, since this may also be masking acute MI symptoms when women do actually come to hospital.

The mortality numbers were “pretty shocking,” Haimi observed: here again, in-hospital mortality was twice as high for women than for men and ranged as high as 10 times higher in the Middle East. The heterogeneity of the data make it impossible to make true comparisons between different regions, he stressed, but he believes people would be surprised to learn that even in North America, in-hospital mortality was 80% higher in women than men in this analysis. 

Moreover, while problems of access to a PCI hospital or delayed STEMI diagnoses might explain higher in-hospital deaths, similar patterns were also seen at 30 days, six months, and one year. At each time point, mortality for women was approximately 75% higher for women than men in the overall analysis, but also in the North American hospitals with even higher numbers in Western Europe.

Door-to-Balloon Times Don’t Hold the Key

Investigators also looked at door-to-balloon times across studies, which were a mean of 5.3 minutes longer in women than those reported for men. Haimi, however, says these numbers likely do not represent the true delay since reporting of door-to-balloon times is not standard in many of the countries whose data were included in the analysis.

Moreover, says Haimi, door-to-balloon times, despite being the gold standard in the US and Europe, hold little value in regions where delays to hospital are the much bigger issue. Symptom-to-reperfusion time would be a more accurate way to measure delays to treatment, particularly when comparing outcomes in men and women. Cultural barriers, infrastructure, and socioeconomic status may all be factors that play a bigger role in delays to treatment among women versus men, although the lack of data makes it impossible to speculate on these issues, Haimi noted.

“The main thing is, these data are the best case scenario”—they represent outcomes for women who actually make it to hospital for treatment. “What we don’t know is, why are there only 32% women [in these registries]? Is it because they don’t come, or are there absolutely fewer women having MIs? We don’t know.”

Haimi believes the most important next step to improving outcomes in women is to collect better data. The Global Lumen Organization for Women (GLOW) is a new initiative led by Lansky and Sameer Mehta, of Cedars Medical Center (Miami, FL) aiming to establish a comprehensive, standardized, internationally organized, data collection program, with the goal of identifying sex-based disparities in care. 

Contacted by TCTMD, Lansky explained that GLOW was launched to address the long known adverse outcomes for women “which we attribute in large part to social, cultural, religious and financial factors,” she said in an email.  “The present results serve as a sobering call for action.” 

A prospective GLOW trial is planned for 10 countries in Asia, the Middle East and South America.

“Something is going on [with STEMI outcomes in women], and nothing small is going to change it,” Haimi said. “The main thing is just getting better data. If we can show people the data, that will move them to action. If people don’t see the data they don’t believe it. You tell people that even in the United States, women show a nearly two-fold higher mortality, in a country where you have a woman running for president, they say, no way. And we’re saying, way.”

Source:
Haimi I, Lee HJ, Mehta S, et al. Gender disparities in ST-Elevation myocardial infarction care and outcomes. A global, systematic meta-analysis of 731,213 patients. Presented at: Cardiovascular Research Technologies, February 21, 2016; Washington, DC.

Disclosures:

• Haimi reports no conflicts of interest.