Addition of papaverine to cardioplegia does not reduce myocardial necrosis

In a randomized, double-blind prospective study involving 495 patients, we investigated whether the addition of papaverine, 60 mg, to our existing regimen of cold cardioplegia would reduce myocardial necrosis during elective coronary artery bypass operations. Twenty-one (4.2%) patients sustained acute postoperative myocardial infarctions (MI), and 7 (1.4%) died during hospitalization. Neither MI nor death was related to papaverine supplementation. Among 469 patients without postoperative MI, levels of the myocardial-specific isoenzyme of creatine phosphokinase measured 10 hours after aortic cross-clamping were related to ischemic cross-clamp time, but not to papaverine supplementation of cardioplegia. At declamping after completion of distal anastomoses, ventricular fibrillation was more common after cardioplegia without papaverine (32% versus 9%). No other differences between the two groups were found in intraoperative and postoperative hemodynamics, difficulty of weaning from bypass, or postoperative volume requirements. We identified three risk factors for postoperative MI: ECG evidence of new ischemia prior to bypass, unusual technical difficulty with distal anastomoses for the surgeon, and prolonged time of ischemia. We conclude that addition of papaverine to our cardioplegia regimen did not affect outcome or nonspecific myocardial necrosis.