Early Invasive Versus Initial Conservative Strategies for Women with Non–ST-Elevation Acute Coronary Syndromes: A Nationwide Analysis

Background Studies conducted largely in men have shown improved outcomes with an early invasive strategy with non–ST-elevation acute coronary syndrome. In contrast, data have been less conclusive in women, with some trials demonstrating potential harm. This study aims to assess whether an early invasive strategy in women is associated with better outcomes in real-world data. Methods Women admitted with a primary diagnosis of non–ST-elevation myocardial infarction or unstable angina were identified from the National Inpatient Sample years 2012 and 2013. The incidence of in-hospital mortality in women with non–ST-elevation acute coronary syndrome undergoing an early invasive strategy versus an initial conservative strategy was compared using a propensity score–matched analysis. Results Among 372,080 women with non–ST-elevation acute coronary syndrome, 153,680 (41.3%) were managed with an early invasive strategy and 218,400 (58.7%) were managed with an initial conservative strategy. Propensity score–matched 19,965 women were treated with an early invasive strategy, and 20,009 women were treated with an initial conservative strategy. The risk of in-hospital mortality was lower with an early invasive strategy (2.1% vs 3.8%; odds ratio [OR], 0.55; 95% confidence interval [CI], 0.49-0.62). This benefit was noted in women presenting with non–ST-segment elevation myocardial infarction (OR, 0.52; 95% CI, 0.46-0.58) and was not observed in women with unstable angina (OR, 5.14; 95% CI, 0.47-56.9), P_interaction =.06. A propensity-adjusted analysis yielded similar results (OR, 0.51; 95% CI, 0.45-0.57). Conclusions In this large contemporary observational analysis of women with non–ST-elevation acute coronary syndrome, an early invasive strategy was associated with lower in-hospital mortality. This benefit was observed in women presenting with non–ST-elevation myocardial infarction but not with unstable angina. These findings provide evidence supporting the guideline recommendations for an early invasive strategy in women with non–ST-elevation acute coronary syndrome and high-risk features (eg, troponin positive).