Impact of sex on comparative outcomes of bivalirudin versus unfractionated heparin in patients with acute coronary syndromes undergoing invasive management: A pre-specified analysis of the MATRIX trial

Aims: Our aim was to assess whether bivalirudin compared with unfractionated heparin (UFH) is associated with consistent outcomes in males and females with acute coronary syndrome (ACS) undergoing invasive management. Methods and results: In the MATRIX programme, 7,213 patients were randomised to bivalirudin or UFH. Patients in the bivalirudin group were subsequently randomly assigned to receive or not a post-PCI bivalirudin infusion. The 30-day co-primary outcomes were major adverse cardiovascular events (MACE), defined as death, myocardial infarction, or stroke, and net adverse clinical events (NACE), defined as MACE or major bleeding. The primary outcome for the comparison of a post-PCI bivalirudin infusion with no post-PCI infusion was a composite of urgent target vessel revascularisation (TVR), definite stent thrombosis (ST), or NACE. The rate of MACE was not significantly lower with bivalirudin than with heparin in male (rate ratio [RR] 0.90, 95% confidence interval [CI]: 0.75-1.07; p=0.22) and female patients (RR 1.06, 95% CI: 0.80-1.40; p=0.67) without significant interaction (pint=0.31), nor was the rate of NACE (males: RR 0.85, 95% CI: 0.72-1.01; p=0.07; females: RR 0.98, 95% CI: 0.76-1.28; p=0.91; pint=0.38). Post-PCI bivalirudin infusion, as compared with no infusion, did not significantly decrease the rate of urgent TVR, definite ST, or NACE (males: RR 0.84, 95% CI: 0.66-1.07; p=0.15; females: RR 1.06, 95% CI: 0.74-1.53; p=0.74; pint=0.28). Conclusions: In ACS patients, the rates of MACE and NACE were not significantly lower with bivalirudin than with UFH in both sexes. The rate of the composite of urgent TVR, definite ST, or NACE was not significantly lower with a post-PCI bivalirudin infusion than with no post-PCI infusion in both sexes.