Acute Coronary Syndrome: The Risk to Young Women.

Background: Although acute coronary syndrome (ACS) mainly occurs in patients >50 years, younger patients can be affected as well. We used an age cutoff of 45 years to investigate clinical characteristics and outcomes of "young" patients with ACS.

Methods And Results: Between October 2010 and April 2016, 14 931 patients with ACS were enrolled in the ISACS-TC (International Survey of Acute Coronary Syndromes in Transitional Countries) registry. Of these patients, 1182 (8%) were aged ≤45 years (mean age, 40.3 years; 15.8% were women). The primary end point was 30-day all-cause mortality. Percentage diameter stenosis of ≤50% was defined as insignificant coronary disease. ST-segment-elevation myocardial infarction was the most common clinical manifestation of ACS in the young cases (68% versus 59.6%). Young patients had a higher incidence of insignificant coronary artery disease (11.4% versus 10.1%) and lesser extent of significant disease (single vessel, 62.7% versus 46.6%). The incidence of 30-day death was 1.3% versus 6.9% for the young and older patients, respectively. After correction for baseline and clinical differences, age ≤45 years was a predictor of survival in men (odds ratio, 0.24; 95% confidence interval, 0.10-0.58), but not in women (odds ratio, 1.35; 95% confidence interval, 0.50-3.62). This pattern of reversed risk among sexes held true after multivariable correction for in-hospital medications and reperfusion therapy. Moreover, younger women had worse outcomes than men of a similar age (odds ratio, 6.03; 95% confidence interval, 2.07-17.53).

Conclusion: ACS at a young age is characterized by less severe coronary disease and high prevalence of ST-segment-elevation myocardial infarction. Women have higher mortality than men. Young age is an independent predictor of lower 30-day mortality in men, but not in women.

Clinical Trial Registration: URL: http://clinicaltrials.gov/. Unique identifier: NCT01218776.