Safety of Single-Dose Histidine-Tryptophan-Ketoglutarate Cardioplegia During Minimally Invasive Mitral Valve Surgery

Objective: Minimally invasive mitral valve surgery may require a prolonged period of myocardial ischemia. Cardioplegic solutions that necessitate a single dose for adequate myocardial protection are evoked to simplify surgery and result to be appealing in this setting. The aim of this study was to assess early outcomes after minimally invasive mitral valve surgery using one single dose of histidine-tryptophan-ketoglutarate solution (HTK; Custodiol) for myocardial protection. Methods: Between February 2003 and October 2012, a total of 49 consecutive patients underwent minimally invasive mitral valve surgery using a single dose of HTK solution for myocardial protection. The patients' mean (SD) agewas 57 (14) years; the preoperative ejection fraction was normal in all cases. The mean (SD) CPB time and aortic cross-clamp time were 148 (45) minutes and 97 (45) minutes, respectively. Results: The heart spontaneously restarted after cross-clamp removal in 37 patients (75.5%). Five patients (10.2%) required prolonged inotropic drug support. Postoperatively, no significant increase in myocardial cytonecrosis enzymes was found [mean (SD) creatine kinase isoenzyme MB, 77.14 (53.67) Kg/L at 3 hours, 71.2 (55.67) Kg/L at 12 hours, and 42.53 (38.38) Kg/L at 24 hours)], and no ischemic electrocardiogram modifications were observed before discharge. Conclusions: During minimally invasive mitral valve surgery, HTK solution provided excellent myocardial protection even after prolonged periods of cardioplegic arrest. The avoidance of repetitive infusions may reduce the risk for coronary malperfusion due to dislodgement of the endoaortic clamp (if used) and increase the surgeon's comfort during the procedure.