Impact of heparin-to-bivalirudin bridging time on hospitalization and safety outcomes in PCI for acute coronary syndrome

Background: Bivalirudin is increasingly used during percutaneous coronary intervention (PCI) for acute coronary syndrome (ACS), but the optimal interval between discontinuing unfractionated heparin (UFH) and initiating bivalirudin remains unclear. This study examined the association between heparin-to-bivalirudin bridging time and clinical outcomes. Methods: This retrospective cohort included 197 ACS patients undergoing PCI. Bridging intervals were evaluated using two predefined thresholds: Scenario A (≤30 vs. >30 min) and Scenario B (≤20 vs. >20 min). Clinical, laboratory, and procedural data were collected. Outcomes included bleeding events, cardiovascular events, rehospitalization, and composite adverse outcomes. Multivariable logistic regression and binomial regression with generalized estimating equations were performed, and restricted cubic spline analyses assessed non-linear associations. Results: In Scenario A, hospitalization occurred significantly less frequently in the ≤30-min group compared with the >30-min group (8.9% vs. 21.6%). After adjustment, longer intervals were associated with higher hospitalization risk (OR = 3.20, 95% CI: 1.20-8.54; RR = 2.55, 95% CI: 1.15-5.66). No differences were observed for bleeding, cardiovascular events, or composite outcomes. In Scenario B, no significant associations were identified for any outcomes. Spline analyses revealed no dose-response relationship between bridging time and clinical outcomes. Conclusions: A heparin-to-bivalirudin bridging interval of ≤30 min may reduce hospitalization without increasing bleeding or cardiovascular events, whereas a 20-min threshold offers no clinical advantage. Bridging time may represent a modifiable procedural parameter that warrants further evaluation in prospective randomized trials. Clinical Trial Registration: ChiCTR2400089671.