Comparison Between Histidine-Tryptophan-Ketoglutarate Cardioplegia and Cold Blood Cardioplegia for Myocardial Protection in Tetralogy of Fallot Patients Undergoing Surgical Repair: A Randomized Clinical Trial.

ABSTRACT

OBJECTIVES: This study was conducted to compare the efficacy of histidine-tryptophan-ketoglutarate (HTK) cardioplegia and cold blood cardioplegia (CBC), especially for postoperative right ventricular (RV) function after tetralogy of Fallot repair. DESIGN: Randomized, double-blinded, parallel-group, controlled clinical trial. SETTING: Ain Shams University Hospitals. PARTICIPANTS: A total of 100 children (1 to 5 years old) scheduled for tetralogy of Fallot repair. INTERVENTIONS: Patients were allocated (double-blinded 11 allocation ratio) to either the HTK group that received HTK cardioplegia (30 mL/kg via antegrade route) or the CBC group that received cold blood cardioplegia with blood-to-Ringer solution (41) in a volume of 20 mL/kg. MEASUREMENTS AND MAIN RESULTS: The HTK group showed a statistically significant reduction of the vasoactive inotropic score on admission to the pediatric intensive care unit (13.0 ± 4.1) in comparison to the CBC group (15.5 ± 5.4), with a p value of 0.011. However, after 24 hours, the vasoactive-inotropic score was comparable. Lactate level during the first 24 hours was 6.2 ± 0.7 mmol/L in the HTK group and 6.9 ± 0.4 mmol/L in the CBC group (p < 0.0001). Serial troponin measurements were lower in the HTK group (1.49 ± 0.45) compared to the CBC group (1.69 ± 0.18) at the first 72 hours postoperatively (p = 0.005). Postoperative echocardiographic assessment of RV function by means of tricuspid annular plane systolic excursion and myocardial performance index were better in the HTK group than in the CBC grpup (p < 0.05). CONCLUSIONS: HTK cardioplegia may offer better cardiac protection to pediatric patients undergoing tetralogy of Fallot repair than our institutional standard CBC with better recovery for the hypertrophic RV.