Assessment of Continuous Cold Blood Cardioplegia in Coronary Artery Bypass Grafting

Abstract

Background. A method of cold blood cardioplegia (CBCP) delivered continuously and in a retrograde manner was compared with methods differing only by their rate (intermittent) or way (antegrade) of administration. Methods. This study comprises 298 consecutive patients undergoing isolated coronary artery bypass grafting procedures performed by the same surgeon from 1992 to 1995. Three-vessel disease characterized 58.8% of the cases, and the left ventricular ejection fraction was less than 0.40 in 22.8%. In group I (n = 100), CBCP was administered in an antegrade and intermittent fashion; in group II (n = 87), CBCP was given in a retrograde and intermittent manner; in group III (n = 111), CBCP delivery was retrograde and continuous. Results. The incidence of major cardiac adverse outcome (death or need for intraaortic balloon counterpulsation) was 7.0% in group I, 8.0% in group II, and 0.9% in group III ( p = 0.040). Repeated-measures analysis of hemodynamic indices showed a marked superiority of continuous retrograde compared with antegrade intermittent blood cardioplegia regarding left ventricular stroke work index ( p < 10 −4) and compared with both methods of intermittent CBCP regarding right ventricular stroke work index ( p < 10 −5). Conclusions. The use of continuous CBCP resulted in a significant reduction in major cardiac events, better left ventricular performance, and a marked improvement of right ventricular function in comparison with similar solutions of blood cardioplegia administered intermittently, independent of their way of delivery.