Longer Ischemic Times in Women with STEMI Due to Age, Comorbidities

Women with ST-segment elevation myocardial infarction (STEMI) experience longer ischemic times than their male counterparts because of advanced age and comorbidities, according to a study published online November 19, 2012, ahead of print in the American Journal of Cardiology. Female sex also independently predicted early all-cause and cardiac mortality after primary percutaneous coronary intervention (PCI).

Investigators led by Martin J. Schalij, MD, PhD, of Leiden University Medical Center (Leiden, The Netherlands), analyzed 3,483 consecutive STEMI patients who underwent primary PCI at 3 Dutch institutions from January 2006 to December 2009. A quarter of the cohort were women (n = 868).

Female Sex Not to Blame for Delays

Median total ischemic and diagnosis-to-balloon times were longer in women compared with men, although there was no difference in door-to-balloon time (table 1).

Table 1. Median Ischemic Times

However, multivariate analysis showed that age per 10-year increase (95% CI 0.01-0.05; P = 0.001), history of diabetes (95% CI 0.03-0.18; P = 0.006), and history of renal insufficiency (95% CI 0.02-0.27; P = 0.020) were independent predictors of longer ischemic time whereas sex was not (95% CI -0.03-0.08; P = 0.295).

All-cause mortality was higher in women compared with men at both 7 days (6.0% vs. 3.0%; P < 0.001) and 1 year (9.9% vs. 6.6%; P = 0.001), although landmark analysis showed that the latter was due to increased early mortality. After adjustment, female sex predicted 7-day all-cause (HR 1.61; 95% CI 1.06-2.46; P = 0.027) and cardiac mortality (HR 1.58; 95% CI 1.03-2.42; P = 0.037), but not 1-year mortality. In addition, sex was an independent effect modifier for cardiogenic shock, leading to substantially worse outcomes in women.

Recognizing STEMI in Key Subgroups

Because sex did not predict longer delays to PCI, Dr. Schalij and colleagues suggest that “the focus should be on the recognition of STEMI in [older patients and those with more comorbidities such as diabetes and renal insufficiency] in men and women.”

Moreover, “[b]ecause the difference in outcomes lay in the early days of hospital admission, the previous observation that more men die before reaching the hospital might explain the difference between men and women, because of a sicker female population being admitted to the hospital,” the authors say. Therefore, they argue, prehospital mortality rates should be incorporated into future similar investigations.

Study Details

Women in the study were typically older, had a higher risk factor burden, and more frequently had histories of malignancy. Men more often had cardiac histories and peripheral vascular disease.

 

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Source:
Velders MA, Boden H, van Boven AJ, et al. Influence of gender on ischemic times and outcomes after ST-elevation myocardial infarction. Am J Cardiol. 2012;Epub ahead of print.

 

 

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