ST-THOMAS-HOSPITAL CARDIOPLEGIA - ENHANCED PROTECTION WITH EXOGENOUS CREATINE-PHOSPHATE

Background. Experimentally, creatine phosphate (CP) improves postische mic recovery of function and reduces postischemic arrhythmias. Methods . We studied 50 patients undergoing valve replacement. They were rando mized into either a control group, who received St. Thomas' Hospital c ardioplegic solution No. 1, or a CP-treated group, receiving the same cardioplegic solution plus CP (10 mmol/L). There were no preoperative clinical differences between groups. Assessment was by electrocardiogr aphic analysis, inotropic drug requirement, quantitative birefringence , myocardial high-energy phosphate content, function, and semiquantita tive ultrastructural assessment. Results. Direct-current shocks were r educed in the CP-treated group (0.88 +/- 0.15) compared with the contr ol group (1.40 +/- 0.14; p < 0.02), as was the total number of joules (22.0 +/- 3.5 versus 34.4 +/- 3.7, respectively; p < 0.02). The incide nce of spontaneous sinus rhythm was higher in the CP-treated group (40 % versus 8%; p < 0.05) and the incidence of postoperative arrhythmias, lower (8% versus 32%; p < 0.05). Prolonged inotropic administration ( 12 hours or longer) occurred in fewer patients in the CP-treated group (4% versus 28%; p < 0.05). Response to inotropic support (in the subs et of patients requiring this treatment) was significantly greater in the CP-treated group than in the control group. There were no differen ces in recovery of function, birefringence changes, myocardial high-en ergy phosphate content, or ultrastructure between groups. Conclusions. St. Thomas' Hospital cardioplegic solution No. 1 plus CP enhanced myo cardial protection and conferred a direct benefit to the patient by re ducing postoperative arrhythmias and need of prolonged inotropic suppo rt.