Effect of adding diltiazem to cold blood potassium cardioplegia on myocardial protection

Abstract

It is still controversial whether the use of calcium channel blockers in cardioplegic solutions decreases ischemic and reperfusion damage. In this study, the effect of diltiazem addition to cold blood potassium cardioplegia in the induction phase on myocardial protection was investigated. A prospective, randomized trial was instituted to evaluate the hemodynamic and myocardial metabolic recovery in 20 patients undergoing elective aortocoronary bypass with either diltiazem in cold blood potassium cardioplegia (diltiazem group, n=10) or cold blood potassium cardioplegia (control group, n=10). In the diltiazem group, 150 mg/kg diltiazem was added to the cardioplegic solution in the induction phase of cardioplegia. In all cases, blood samples for measurement of lactate level and calculation of lactate extraction were taken from coronary sinus and radial artery at the beginning and the 30th minute of reperfusion period. CK-MB levels were measured in the intensive care at postoperative 6th and 18th hours. The hemodynamic findings of both diltiazem and control groups were compared in the preoperative and early postoperative periods. Lactate production was significantly lower in the diltiazem group at the beginning of the reperfusion period (p<0.01). Calculated lactate extractions were similar in the two groups at the 30th minute of reperfusion (p>0.05). CK-MB level was significantly higher in the control group in the postoperative period. Similar hemodynamic findings were obtained in both groups in the preoperative and the early postoperative periods. We concluded that diltiazem addition to cold blood potassium cardioplegia decreases ischemic and reperfusion damage and has a beneficial effect on myocardial protection.