Activated clotting time post therapeutic anticoagulation with unfractionated heparin in patients undergoing elective percutaneous coronary intervention

Abstract

To investigate the activated clotting time (ACT) level after administration of guideline-recommended dose of unfractionated heparin (UFH) and to confirm the importance of ACT monitoring in percutaneous coronary intervention (PCI). We performed a retrospective study on 1 062 patients undergoing elective PCI in Peking Union Medical College Hospital from May 1, 2011 to December 31, 2012. All patients were administrated weight-adjusted UFH (70-100 U/kg) based on PCI guideline of ACCF/AHA/SCAI. Patients were divided into 3 groups: ACT < 300 s (598 cases), ACT 300-350 s (183 cases) and ACT > 350 s (281 cases). ACT level and factors that may affect UFH anticoagulation were analyzed. (1) The mean age was (63.0 ± 10.6) years and 751 (70.7%) patients were men. The mean weight was (70.5 ± 11.7) kg, and the mean UFH dose used was (100.7 ± 9.1) U/kg. (2) The median ACT was 285 (240-352) s after the UFH use. Pre-defined ACT target (300-350 s) was achieved only in 17.2% (183/1 062) patients. (3) Age, gender, height, weight, UFH/weight and the risk factors of coronary heart disease were similar among 3 groups (all P > 0.05). Multifactor linear correlation analysis showed that UFH/weight was related to ACT level (r = 0.07, P < 0.01), but other factors were not related to ACT level (all P > 0.05). (4) Among 598 patients with ACT < 300 s, 444 (74.2%) patients received additional UFH. No major bleeding events were observed in 1 062 patients. The incidence of minor bleeding and ischemic complications within 48 h after procedure were similar among 4 groups of ACT < 300 s with additional UFH, ACT < 300 s without additional UFH, ACT 300-350 s and ACT > 350 s (all P > 0.05). In this single-center study, only a small proportion of patients reached the ACT target after administration of weight-adjusted UFH. Our results supported the recommendation of ACT monitoring in current PCI guideline to improve efficacy and safety of UFH anticoagulation therapy.