Safety of routine protamine in the reversal of heparin in percutaneous coronary intervention: A systematic review and meta-analysis

Objectives: To determine the safety and efficacy of protamine in the reversal of heparin in percutaneous coronary intervention (PCI). Background: Heparin is routinely used for anticoagulation in PCI. Protamine is not used routinely to reverse heparin's effects in PCI, partly due to the perceived risk of stent thrombosis. Methods: Relevant studies published in English were searched for in PubMed, Embase, and Cochrane databases from inception to April 26th, 2023. Our primary outcome of interest was stent thrombosis in patients receiving PCI for all indications. Secondary outcomes included mortality, major bleeding complications, and hospitalization length. Dichotomous outcomes were analyzed using a Mantel-Haenszel random-effects model and expressed as odds ratios (OR) with their 95% confidence intervals (CI), while continuous outcomes were analyzed using an inverse variance random-effects model expressed as mean differences (MD) with their 95% CI. Results: 11 studies were included in our analysis. Protamine use was not associated with stent thrombosis: OR 0.58, 95% CI: 0.33, 1.01 (p = 0.05) nor with mortality (p = 0.89). Protamine administration was associated with a decreased incidence of major bleeding complications: OR 0.48; 95% CI: 0.25, 0.95 (p = 0.03) and decreased length of hospitalization (p < 0.0001). Conclusions: In patients pre-treated with dual antiplatelet therapy (DAPT), protamine may be a safe and efficacious option to facilitate earlier sheath removal, reduce major bleeding complications, and reduce length of hospitalization without increased risk of stent thrombosis.