Antegrade versus Retrograde Cardioplegia for Uncomplicated Coronary Artery Disease: A Comparative Study

Abstract

Since the introduction of the retrograde administration of cardioplegic solutions in cardiac surgery in the mid-1980's, the technique has been widely adopted for routine use in high risk patients with impaired ventricular function, based on favorable results demonstrated in clinical series. However, we sought to evaluate the benefits of routine use of this method in low risk patients by means of a retrospective review of 34 consecutive non-repeat, isolated coronary artery bypass grafting patients with left ventricular ejection fractions > 35%. Seventeen patients received intermittent ante grade cardioplegia exclusively and 17 received ante grade induction followed by intermittent retrograde cardioplegia maintenance. No significant baseline differences were found between the two groups. There were no deaths or major complications in either group. Retrograde cardioplegia patients had significantly lower pulmonary artery diastolic pressures in the first 24 hours postoperatively, accompanied by a non-significant trend toward higher cardiac indices during this same period. Phenylephrine infusions were used more frequently during the postoperative period in the retrograde group (p = 0.021). Fewer pulmonary complications were seen in the retrograde cardioplegia group (p=0.042), in addition to non-significant trends toward less atrial arrhythmias and less hospital days. No adverse effects or increased operative time could be attributed to the retrograde administration of cardioplegic solution in this study population. Based on the results from this small clinical series, retrograde cardioplegia administration offers distinct advantages for myocardial protection in low risk coronary bypass patients, as manifested by improved postoperative hemodynamic performance, with no significant adverse effects. A prospective, randomized trial of this technique in a larger, similar patient population is likely to show even more compelling positive results favoring the routine use of retrograde administration of cardioplegic solutions.