In a randomized trial of 60 adults undergoing CABG for left main coronary artery disease, combined antegrade–retrograde blood cardioplegia did not significantly reduce peak troponin I compared with antegrade-only delivery. Both strategies had similar early clinical outcomes, and no cardioplegia-related complications occurred. The single-center trial supports individualized myocardial protection rather than routine combined delivery, but it cannot establish equivalence or exclude modest benefits.