[Evaluation of the effectiveness and safety in the use of cold-diltiazem-potassium cardioplegia in coronary artery bypass surgery: a first clinical trial].

The effectiveness and safety of diltiazem (DIL), a slow channel calcium blocker, added in cold potassium cardioplegic (CP) solution was evaluated in coronary artery bypass graft (CABG) surgery for 2 purposes; (1) protection of ischemic myocardium during cardiac arrest and (2) prevention of perioperative coronary artery spasm (PCS). Diltiazem of 15 mg was added to a liter of CP which was administered 10 ml/kg B.W. initially and 5mg/kg thereafter. The serum concentration of DIL was 570 ng/ml at the time of aortic declamping, 210 ng/ml at cardioversion and 150 ng/ml one hour after surgery. The left ventricular stroke work index was increased significantly (p less than 0.05) in patients treated by DIL-CP, compared with the patients treated by regular CP without DIL. However, CPK-MB values were not significantly different in either group. The incidence of PCS has decreased from 9.1% to 0.8% (p less than 0.01) after the use of DIL-CP. Perioperative myocardial infarction rate has also decreased from 5.5% to 1.6%. No major or long-lasting side-effects were encountered. We consider that DIL-CP is a safe and excellent CP in CABG surgery and we are now utilizing this CP in all patients requiring CABG surgery.