Comparison of del Nido and histidine-tryptophan-ketoglutarate cardioplegia solutions in pediatric patients undergoing open heart surgery: A prospective randomized clinical trial.

Objectives: We conducted a prospective randomized controlled trial to compare del Nido (DN) and histidine-tryptophan-ketoglutarate (HTK) cardioplegia solution in pediatric patients undergoing intracardiac tetralogy of Fallot repair.

Methods: One hundred consecutive patients 12 years of age or younger, undergoing intracardiac repair of tetralogy of Fallot were randomized into DN (n = 50) and HTK (n = 50) groups. Cardioplegia strategy consisted of a single dose of DN (20 mL/kg) or HTK (6 mL/kg/min for 6 minutes). Primary outcome was cardiac index (CI). Secondary outcomes were ventricular arrhythmias post cross-clamp release, time to peripheral rewarming, duration of mechanical ventilation, inotropic score, intensive care unit and hospital stay, and serum levels of troponin-I, interleukin-6, and tumor necrosis factor-α. Ultrastructural changes in the myocardium were assessed.

Results: CI was significantly higher in the DN group compared with the HTK group at 6 (P = .005) and 24 hours (P < .001) after surgery. It was on an average 0.44 L/min/m higher in the DN group at any time point (P = .004). Time for complete cessation of electrical activity was longer in the HTK group (P = .01) and more patients in the HTK group had ventricular arrhythmias post cross-clamp release (P = .03). Duration of mechanical ventilation (P = .006), intensive care unit stay (P = .05), and hospital stay (P < .001) were lower in the DN group. Patients in the DN group had lower troponin I levels 24 hours after cardiopulmonary bypass (P < .001). Electron microscopic studies showed more myocardial edema (P = .02) and myofibrillar disarray (P = .04) in the HTK group along with lower glycogen stores (P = .04). DN cardioplegia was more cost-effective than HTK cardioplegia (P < .001).

Conclusions: DN cardioplegia was associated with better preservation of CI, less duration of mechanical ventilation, shorter intensive care unit and hospital stays, lower inotropic scores, and less release of troponin-I. Electron microscopy showed less myocardial edema and better preservation of the myofibrillar architecture and glycogen stores in the DN group.