Introduction: The cornerstone of myocardial protection today is administration of blood cardioplegia. Over the last 3 years (2010-2013) we started employing cold crystalloid cardioplegia: histidine-tryptophan-ketoglutarate (HTK) for complex operations. This solution is unique since it safely affords 120 minutes or more of un-interrupted cross clamping of the aorta. We present our initial experience with HTK in patients undergoing mitral surgery.
Patients: Overall, 211 patients received HTK cardioplegia, 146 underwent mitral surgery. Patient age was 65+10 years, 123 (84%) were in NYHA class III-IV, 58 (40%) were in atrial fibrillation. Predicted mortality by logistic EuroSCORE was 13+17%. The mitral valve was repaired in 44 and replaced in 102. Isolated mitral procedure was performed in 29. Concomitant procedures included CABG in 45, TVA in57, AVR in 37, and other in 87. Administration was antegrade in all, either via the aortic root, or direct cannulation of the coronary ostia. These patients were compared to a propensity matched cohort of 292 patients receiving cold blood cardioplegia.
Results: Bypass and aortic clamp time were 139+78 and 106+36 minutes respectively. Forty-eight (33%) patients required inotropes after surgery; 71 (49%) required ventilation beyond 24 hours. Operative mortality was 13% (19 patients). Predictors for operative mortality were age (p=0.02), urgency (p=0.05) and need for inotropes (p=0.02). Results were similar in the matched cohort.
Conclusions: In our experience single dose HTK solution affords excellent myocardial protection equivalent to cold blood cardioplegia. This is especially beneficial in complex surgery and mitral surgery in particular, since there is no need for interruption of the procedure in order to deliver additional doses. Once acquiring familiarity and comfort with this solution we employ it routinely in all cases with prolonged expected cross clamp time
