Sex Differences in Ischemic and Bleeding Outcomes in Patients With Non-ST-Segment-Elevation Acute Coronary Syndrome Undergoing Percutaneous Coronary Intervention: Insights From the TAO Trial

Background: Previous studies have observed poorer outcomes in females with myocardial infarction, but older age and lower use of percutaneous coronary intervention in females are factors that potentially explain the worse outcome. This study sought to determine if female sex is an independent factor of ischemic and bleeding outcomes in non-ST-segment-elevation acute coronary syndrome treated with a systematic invasive approach.

Methods: The TAO trial (Treatment of Acute Coronary Syndrome With Otamixaban) randomized patients with non-ST-segment-elevation acute coronary syndrome treated invasively to heparin plus eptifibatide versus otamixaban. In this post hoc analysis, the primary ischemic end point (all-cause death, myocardial infarction within 180 days) and the primary safety end point (Thrombolysis in Myocardial Infarction major or minor bleeding within 30 days) were analyzed according to sex.

Results: Of 13 229 randomized patients, 3980 (30.1%) were females and 9249 (69.9%) were males. Females were older (64.8±11.0 versus 60.7±11.1 years), had more comorbidities, received less peri-procedural antithrombotic therapy, and underwent less frequently revascularization. Overall, females experienced a higher risk of ischemic (10.2% versus 9.1%; odds ratio [OR], 1.15 [1.01-1.30]) and bleeding events (4.2% versus 3.4%; OR, 1.23 [1.02-1.49]) than males. After multivariate analysis, the risk of ischemic outcomes (OR, 1.04 [0.90-1.19]), death (OR, 1.00 [0.75-1.23]), or bleeding (OR, 1.05 [0.85-1.28]), were similar between females and males. Only, noncoronary artery bypass graft related Thrombolysis in Myocardial Infarction major bleeding were increased in females (OR, 1.69 [1.11-2.56]).

Conclusions: In patients with non-ST-segment-elevation acute coronary syndrome with systematic invasive management, ischemic outcomes, bleeding events, and mortality were higher in females. After multivariate analyses, female sex was not an independent predictor of ischemic and bleeding events although noncoronary artery bypass graft related Thrombolysis in Myocardial Infarction major bleeding was higher in females. Registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT01076764.