Effects of early application of heparin on coronary blood flow during primary percutaneous coronary intervention

Purpose: To investigate the efficacy and safety of unfractionated heparin (UFH) anticoagulant administered upstream in the ambulance or emergency room during primary percutaneous coronary intervention (pPCI) for patients with acute ST-segment elevation myocardial infarction (STEMI).Methods: The study included STEMI patients who received either early UFH subcutaneously (SC) (n = 163) or intraoperative UFH (SC) during pPCI (n = 476) between January 2017 to August 2018. Baseline characteristics, infarct-related artery (IRA) status, and procedural characteristics were analyzed. The primary endpoint was thrombolysis in myocardial infarction (TIMI) flow grade 2 - 3 before intervention. The secondary endpoints were time from first medical contact to guidewire passage, postoperative TIMI 3 flow grade, acute stent thrombosis, and in-hospital bleeding events.Results: Baseline characteristics were similar between the groups, with no significant difference in IRA location. Both groups underwent coronary angiography, with most patients receiving pPCI. The primary endpoint occurred in 18.1 % of patients in intraoperative UFH group and 27.6 % in the early UFH group, with a significant difference between the groups (p < 0.05). There was no significant difference in postoperative TIMI 3 flow grade or acute stent thrombosis, but bleeding events (BARC 2-5) were similar between groups (1.1 % in intraoperative group and 1.8 % in early UFH group, p > 0.05)Conclusion: Early upstream administration of UFH anticoagulation in STEMI patients improves coronary artery potency before pPCI, and early use of fixed-dose UFH is safe and does not increase major bleeding complications.