Bivalirudin or unfractionated heparin in patients with acute coronary syndromes managed invasively with and without ST elevation (MATRIX): Randomised controlled trial

OBJECTIVE: To test the optimal antithrombotic regimen in patients with acute coronary syndrome.
DESIGN: andomised controlled trial.
SETTING: Patients with acute coronary syndrome with and without ST segment elevation in 78 centres in Italy, the Netherlands, Spain, and Sweden.
PARTICIPANTS: 7213 patients with acute coronary syndrome and planned percutaneous coronary intervention: 4010 with ST segment elevation and 3203 without ST segment elevation. The primary study results in the overall population have been reported previously.
INTERVENTIONS: Patients were randomly assigned, in an open label fashion, to one of two regimens: bivalirudin with glycoprotein IIb/IIIa inhibitors restricted to procedural complications or heparin with or without glycoprotein IIb/IIIa inhibitors.
MAIN OUTCOME MEASURES: Primary endpoints were the occurrence of major adverse cardiovascular events, defined as death, myocardial infarction or stroke; and net adverse clinical events, defined as major bleeding or major adverse cardiovascular events, both assessed at 30 days. Analyses were performed by the principle of intention to treat.
RESULTS: Use of a glycoprotein IIb/IIIa inhibitor in patients assigned to heparin was planned at baseline in 30.7% of patients with ST segment elevation, in 10.9% without ST segment elevation, and in no patients assigned to bivalirudin. In patients with ST segment elevation, major adverse cardiovascular events occurred in 118 (5.9%) assigned to bivalirudin and 129 (6.5%) assigned to heparin (rate ratio 0.90, 95% confidence interval 0.70 to 1.16; P=0.43), whereas net adverse clinical events occurred in 139 (7.0%) patients assigned to bivalirudin and 163 (8.2%) assigned to heparin (0.84, 0.67 to 1.05; P=0.13). In patients without ST segment elevation, major adverse cardiovascular events occurred in 253 (15.9%) assigned to bivalirudin and 262 (16.4%) assigned to heparin (0.97, 0.80 to 1.17; P=0.74), whereas net adverse clinical events occurred in 262 (16.5%) patients assigned to bivalirudin and 281 (17.6%) assigned to heparin (0.93, 0.77 to 1.12; P=0.43).
CONCLUSIONS: A bivalirudin monotherapy strategy compared with heparin with or without glycoprotein IIb/IIIa inhibitors, did not result in reduced major adverse cardiovascular events or net adverse clinical events in patients with or without ST segment elevation.
TRIAL REGISTRATION: ClinicalTrials.gov NCT01433627.