Combined Antegrade-Retrograde Cardioplegia for Myocardial Protection During Coronary Artery Bypass Grafting in Patients with Left Main Coronary Artery Disease: The CARDIOPROTECT-LMCAD Randomised Trial

Background and Objectives: Myocardial protection during on-pump coronary artery bypass grafting (CABG) limits ischaemic injury, particularly in patients with left main coronary artery disease (LMCAD), in whom severe proximal stenosis may compromise antegrade cardioplegia delivery. We investigated whether combined antegrade-retrograde blood cardioplegia reduces postoperative high-sensitivity cardiac troponin I (hs-cTnI) concentrations, a marker of perioperative myocardial injury. Materials and Methods: We conducted a prospective, single-centre, randomised trial involving 60 adults undergoing elective isolated on-pump CABG for significant LMCAD. Patients were assigned (1:1) to antegrade-only or combined antegrade-retrograde blood cardioplegia. Cardiac biomarkers were measured after induction and at 4, 12, 24, and 48 h after ICU admission. The primary endpoint was peak hs-cTnI within 48 h; key secondary endpoints included the hs-cTnI area under the concentration-time curve, CK-MB, immediate myocardial electrical recovery and 30-day outcomes.