Cardioplegia Strategies in Aortic Stenosis: A Focused Review of Current Evidence for Surgical Considerations

Severe aortic stenosis (AS) exposes the hypertrophied myocardium to cardioplegic arrest in the setting of increased left ventricle (LV) mass, interstitial fibrosis, impaired relaxation, coronary microvascular dysfunction, and reduced perfusion reserve. These abnormalities may increase susceptibility to ischemic injury and complicate homogeneous cardioplegic delivery. This focused narrative review synthesizes physiological and clinical evidence on cardioplegia composition, temperature, delivery route, dosing, redosing, and myocardial protection during prolonged aortic cross-clamping in adults undergoing surgical aortic valve replacement. AS-specific comparative studies remain limited, generally small, and frequently reliant on biochemical markers; meanwhile, larger observational cohorts and contemporary randomized aortic valve replacement (AVR) trials also vary substantially in patient selection and myocardial protection protocols. Although some studies have associated cold blood cardioplegia with lower biomarker release than cold crystalloid cardioplegia, and cold maintenance strategies with less biochemical injury than warm cardioplegia, no formulation, temperature, or delivery route has demonstrated consistent superiority in clinically important outcomes. Limited historical evidence also suggests that body weight-based dosing may inadequately reflect myocardial requirements in marked LV hypertrophy, but no validated LV mass-based regimen currently exists. Therefore, cardioplegia in severe AS should be considered within a comprehensive myocardial protection protocol incorporating composition, temperature, dose, delivery route, redosing strategy, myocardial phenotype, associated valve or coronary disease, and anticipated cross-clamp duration. Prospective AS-specific studies using standardized protocols, LV mass stratification, and clinically meaningful outcomes are required.