Post-procedural Anticoagulation With Unfractionated Heparin in Acute Coronary Syndrome: Insight from the STOPDAPT-3 Trial

•In a post hoc analysis of a recent Japanese clinical trial, more than half of the patients with acute coronary syndromes received anticoagulation with unfractionated heparin after percutaneous coronary intervention (PCI). This was especially true for patients with ST-segment elevation myocardial infarction or intraprocedural adverse angiographic findings.•Post-PCI heparin administration was associated with significantly higher incidence of bleeding events without any benefit in reducing cardiovascular events within 30 days after PCI.•Higher heparin doses per body weight and total doses were associated with higher rates of both bleeding and cardiovascular events. The current guidelines for acute coronary syndrome (ACS) discourage the use of anticoagulation after percutaneous coronary intervention (PCI) without specific indications, although the recommendation is not well supported by evidence. In this post hoc analysis of the ShorT and OPtimal Duration of Dual AntiPlatelet Therapy-3 (STOPDAPT-3) trial, 30-day outcomes were compared between the 2 groups with and without post-PCI heparin administration among patients with ACS who did not receive mechanical support devices. The co-primary end points were the bleeding end point, defined as the Bleeding Academic Research Consortium type 3 or 5 bleeding, and the cardiovascular end point, defined as a composite of cardiovascular death, myocardial infarction, definite stent thrombosis, or ischemic stroke. Among 4,088 patients with ACS, 2,339 patients (57.2%) received post-PCI heparin. The proportion of patients receiving post-PCI heparin was higher among those with ST-elevation myocardial infarction compared with others (72.3% and 38.8%, p