Retrograde crystalloid cardioplegia preserves left ventricular systolic function better than antegrade cardioplegia in patients with occluded coronary arteries

Objective: To investigate retrograde and antegrade crystalloid cardioplegia in terms of cardiac cooling and postoperative cardiac function. Design: Prospective, randomized, and blinded. Setting: University hospital. Participants: Twenty male patients with triple-vessel disease and proximal occlusion of the circumflex or the left anterior descending coronary artery . Interventions: Left ventricular ejection fraction at rest and during exerci se was evaluated by nuclear ventriculography the day before and 3 months af ter surgery. After induction of anesthesia and hourly for the first 5 posto perative hours, hemodynamic. echocardiographic, and electrocardiographic da ta were acquired. Myocardial temperature was measured with needle thermisto rs in 3 myocardial regions. Measurements and Main Results: Demographic and temperature data were analyz ed by t-test. Hemodynamic and echocardiographic data were analyzed by analy sis of variance. The groups were similar in baseline characteristics. Retro grade cardioplegia cooled the region distal to an occlusion better than ant egrade cardioplegia (9.6 degrees C +/- 4.8 degrees C v 21.8 degrees C +/- 5 .9 degrees C; p < 0.01). Hemodynamic, echocardiographic, and electrocardiog raphic data did not differ between the groups. Three months after surgery, the retrograde cardioplegia group showed a higher left ventricular ejection fraction at rest (58% +/- 10% v 47% +/- 10%; p < 0.02) and during exercise (58% +/- 13% v 47% +/- 10%; p < 0.05) compared with the antegrade cardiopl egia group. Conclusions: Retrograde cardioplegia provides more homogenous myocardial co oling than antegrade cardioplegia in hearts with coronary artery occlusions . The use of retrograde cardioplegia seems to benefit long-term left ventri cular function. Copyright (C) 2000 by W.B. Saunders Company.