The use of exogenous creatine phosphate for myocardial protection in patients undergoing coronary artery bypass surgery.

A key component in the development of ischemic functional and structural myocardial injury during cardiosurgical procedures is an inadequate cellular energy supply which occurs as a consequence of the cessation of oxidative metabolism. In such conditions high energy phosphates are rapidly depleted. As they play a critical role in the maintenance of cell viability and postischemic recovery of contractile function, their conservation is therefore a primary objective in any procedure designed to reduce ischemic injury. Exogenous administration of phosphocreatine (CP) has been suggested as being beneficial to the ischemic heart. The aim of present study was to evaluate the possible cardioprotective effect of exogenous CP during coronary artery surgery (CABG). Forty patients undergoing CABG procedure were randomly assigned to receive creatine phosphate-enriched (group I) or standard-St. Thomas' Hospital (group II) cardioplegic solution; each group comprised 20 patients. Group I received: 6.0 g of exogenous CP (Neoton) daily in two 20-min intravenous infusions during 3 days preoperatively; during surgical procedure they were administered standard cardioplegic solution enriched in CP at the concentration of 10 mmol/l and -- 2 days postoperatively -- 4.0 g CP daily in two intravenous injections. Group II did not receive CP at all In both groups were analysed. Haemodynamic parameters. Continuous 48-h ECG recording (Holter monitoring) outcome. Laboratory values of serum CK and CK-MB. Inotropic support required (drugs, mechanical support). Ultrastructural findings (biopsy data). Statistical analysis was carried out using Student's "t"-test and the chi2 test. Values of p<0.05 were taken as the criterion of significant difference. The results of the study were: Significantly lower average number and energy of DC-shocks needed to restore cardiac function after cardiopulmonary bypass procedure in group 1. Statistically significant beneficial effect on the presence of ventricular arrhythmias during surgery and in early postoperative period in group I. Significantly lower requirements for inotropic drugs postoperatively in group I. Statistically significant lower degree of sarcolemmal damages in myocardial biopsies in group I. Concluding, the authors wish to state that: Exogenous phosphocreatine (Neoton) perioperative administration in coronary artery bypass patients reduced the need for inotropic drugs, which is clinically manifested in lower frequency of low cardiac output syndrome. Perioperative administration of exogenous CP improves electrophysiological stability of the myocardium. Advantageous clinical and electrophysiological effect of exogenous CP may result from its properties to protect sarcolemma of the cardiomyocytes.