Effect of induction and reperfusion with warm substrate-enriched cardioplegia on ventricular function

Background. This study tested the hypothesis that induction and reperfusion with warm substrate-enriched (IRWSE) blood cardioplegia improves postopera tive left ventricular (LV) function in patients undergoing elective coronar y bypass surgery (CABG). Methods. After giving informed consent, 67 patients scheduled for CABG surg ery were randomized to either IRWSE + cold blood (CB) or CB alone. IRWSE ca rdioplegia consisted of 37 degrees C substrate-enriched (glutamate, asparta te, hyperkalemic) anterograde and retrograde blood cardioplegic solution fo llowed by non-substrate-enriched cardioplegic solution given at 4 degrees C to 8 degrees C. LV function was measured with ventriculograms, volume cond uctance catheters, echocardiography, and multiple gated (image) acquisition . Results. The end-systolic pressure-volume relationship was improved postbyp ass in the IRWSE + CB group (CB, 1.5 +/- 0.74 mm Hg/mL vs IRWSE + CB, 2.1 /- 1.2 mm Hg/mL; p = 0.042). The postoperative ejection fraction (EF%) was better preserved in the CB group (CB, 65 +/- 11.53% vs IRWSE + CB, 58.62 +/ - 11.75%; p < 0.04). Conclusions. Our results demonstrate a transient improvement in LV systolic function in the immediate postbypass period in CABG patients in the IRWSE + CB group. The intraoperative benefits of the IRWSE + CB technique did not persist in the postoperative period. (C) 2000 by The Society of Thoracic S urgeons.