Association of Parenteral Anticoagulation Therapy With Outcomes in Non–ST‐Segment Elevation Acute Coronary Syndrome Patients Without Invasive Therapy: Findings from the Improving Care for Cardiovascular Disease in China (CCC) project

Our previous study showed that parenteral anticoagulation therapy (PACT) in the context of aggressive antiplatelet therapy failed to improve clinical outcomes in patients undergoing percutaneous coronary intervention for non-ST-segment elevation acute coronary syndrome (NSTE-ACS). However, the role of PACT in patients managed medically remains unknown. This observational cohort study enrolled patients with NSTE-ACS receiving medical therapy from November 2014 to June 2017 in the Improving Care for Cardiovascular Disease in China-Acute Coronary Syndrome project. Eligible patients were included in the PACT group and non-PACT group. The primary outcomes were in-hospital all-cause mortality and major bleeding. The secondary outcome included minor bleeding. Among 23,726 patients, 8,845 eligible patients who received medical therapy were enrolled. After adjusting the potential confounders, PACT was not associated with a lower risk of in-hospital all-cause mortality (adjusted odds ratio (OR), 1.25; 95% confidence interval (CI), 0.92-1.71; P = 0.151). Additionally, PACT did not increase the incidence of major bleeding or minor bleeding (major bleeding: adjusted OR, 1.04; 95% CI, 0.80-1.35; P = 0.763; minor bleeding: adjusted OR, 1.27; 95% CI, 0.91-1.75; P = 0.156). The propensity score analysis confirmed the primary analyses. In patients with NSTE-ACS receiving antiplatelet therapy, PACT was not associated with a lower risk of in-hospital all-cause mortality or a higher bleeding risk in patients with NSTE-ACS receiving non-invasive therapies and concurrent antiplatelet strategies. Randomized clinical trials are warranted to reevaluate the safety and efficacy of PACT in all patients with NSTE-ACS who receive noninvasive therapies and current antithrombotic strategies.