Body weight rather than unfractionated heparin dose predicts periprocedural bleeding during elective PCI.

Background: Optimal anticoagulation during elective percutaneous coronary intervention (PCI) remains uncertain, particularly in East Asian populations with lower body weight and increased bleeding susceptibility. We investigated the association of body weight and unfractionated heparin (UFH) dose with periprocedural bleeding during elective PCI. Methods and Results: This retrospective single-center study included 348 Japanese patients undergoing elective PCI. Patients received either fixed-dose UFH (10,000 U) or weight-adjusted UFH (100 U/kg). Within the fixed-dose group, patients were stratified according to weight-adjusted UFH exposure (≥150 vs. <150 U/kg). The primary endpoint was Bleeding Academic Research Consortium (BARC) type 1 or 2 bleeding. Bleeding events were less frequent in the low-dose than in the high-dose group (24% vs. 40%, P < 0.001). No significant differences in major cardiovascular events were observed during follow-up. In multivariable analysis, lower body weight was associated with increased bleeding risk (OR 0.948, 95% CI 0.905-0.994, P = 0.027), whereas UFH dose was not independently associated with bleeding. Conclusions: Lower body weight may be more closely associated with periprocedural bleeding than UFH dose during elective PCI. Careful bleeding risk assessment may therefore be warranted in patients with low body weight undergoing PCI.