Emergency coronary artery surgery after failed PTCA:: Myocardial protection with continuous coronary perfusion of beta-blocker-enriched blood

Background: Myocardial protection during cardiac surgery in patients with acute ischemia after failed PTCA remains a challenge. Our recent experimental work demonstrated that continuous coronary perfusion with warm beta-blocker-(Esmolol) enriched blood may be a useful alternative to current cardioplegia techniques, especially for compromised hearts. This technique was applied in our last 12 patients after failed PTCA (beta-B). The purpose of this retrospective study was to compare this alternative myocardial protection technique with our standard technique of cold crystalloid cardioplegia (CP). Methods: Between January 1994 und January 1998 fifty-five patients (beta-B: n = 12; CP: n = 43) underwent emergency coronary artery bypass grafting within 24 hours after failed PTCA. The mean age in beta-B patients was 62 +/- 9 (SD) years, and 33 % were female (CP: 59 +/- 9 years, 42% female, p = NS). In beta-8 patients 67% had myocardial infarction (MI) prior to coronary angioplasty, 67% had an ejection fraction (EF) > 55 %, and coronary vessel involvement (VI) was 2.1 +/- 0.7. CP patients had the following findings: MI rate 42%, EF > 55% in 84%, VI was 2.2 +/- 0.6; p = NS. Operation commenced within 25 - 980 min after failed PTCA. beta-B patients received 2.7 +/- 0.8 grafts during 45 +/- 20 min continuous coronary perfusion with Esmolol enriched blood, whereas CP patients had 3.0 +/- 1.1 grafts in 42 +/- 17 min cross-clamp time, p = NS. Results: The total hospital stay was significantly (p = 0.004) shorter for beta-B patients (18 +/- 8 days) compared to CP patients (27 +/- 12 days). 30-days mortality rate was 9% in CP patients, whereas none of the beta-B patients died. Postoperative low cardiac output occurred in only one patient (8 %) of the beta-B group and was treated with an intraaortic balloon pump (IABP). Eight (19%) of the CP patients required an IABP and in five (12%) patients an additional ventricular assist device was necessary (LVAD: n = 4: RVAD: n = 1). The need for circulatory support with inotropes was significantly lower in beta-B patients. Cumulative postoperative dosage of dopamine and dobutamine was 34 516 +/- 40400 mu g/kg and 16221 +/- 26678 mu g/kg respectively in CP patients. beta-B patients required only 12457 +/- 14738 mu g/kg (p = 0.02) dopamine and 5112 +/- 7381 mu g/kg (p = 0.01) dobutamine. Perioperative myocardial infarction occurred in 53% of the CP patients and 17% of beta-B patients (p = 0.046). Total CKmax was significantly (p = 0.003) higher in CP patients (812 +/- 531 U/L) than in beta-B patients (457 +/- 265 U/L). Four CP patients (9%) had acute postoperative renal failure requiring hemofiltration, and 11 CP patients (26%) had acute postoperative pneumonia. In beta-B patients one patient (8%) suffered from postoperative pneumonia (p = NS) and no patient had renal failure (p = NS). Conclusion: These clinical results appear to confirm our experimental data and suggest that continuous coronary perfusion with warm esmolol-enriched blood is superior to crystalloid cardioplegia in terms of in-hospital complications and mortality, especially for compromised hearts after failed PTCA.