PRISMA Flow Diagram

This study is a <b>systematic review and meta-analysis</b> evaluating the safety and efficacy of <b>bivalirudin as an anticoagulant</b> in patients with <b>heparin-induced thrombocytopenia (HIT)</b> undergoing <b>cardiac surgery with cardiopulmonary bypass (CPB)</b>. Since unfractionated heparin is contraindicated in HIT, bivalirudin has emerged as the main alternative, but high-quality data remain scarce.<b>Methods:</b> The review followed <b>PRISMA 2020 guidelines</b> and was prospectively registered in <b>PROSPERO</b>. Searches across PubMed, Embase, and Cochrane CENTRAL identified <b>three cohort studies (170 patients)</b> plus <b>16 case reports/series</b>. Primary outcomes were <b>major bleeding, thromboembolic events, and mortality</b>; secondary outcomes included transfusion needs, reoperation, circuit changes, and ICU/hospital stay.<b>Results:</b><b>Major bleeding:</b> 10.6% pooled incidence (95% CI 6.4–16.9%).<b>Thromboembolic events:</b> 2.1% pooled incidence (95% CI 0.4–4.8%), with no CPB circuit thrombosis or oxygenator exchanges.<b>Mortality:</b> Early mortality ≤3%.Around <b>14% of patients required intraoperative dose adjustments</b>, but <b>ACT-guided protocols (480–520 s)</b> ensured safe management.Case-based evidence confirmed feasibility in <b>high-risk settings</b> (pediatrics, reoperations, transplantation, renal impairment).<b>Conclusions:</b> Bivalirudin is a <b>safe and effective alternative to heparin</b> in HIT-positive patients requiring CPB, with <b>low thrombotic risk and acceptable bleeding rates</b> under strict ACT monitoring. Findings are consistent with <b>international guidelines (ASH 2018, ACCP 2022)</b>, though <b>large randomized trials</b> are still needed to refine dosing strategies and long-term outcomes