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 and 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-B 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 intra-aortic 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 34516+/-40400 microg/kg and 16221+/-26678 microg/kg respectively in CP patients. Beta-B patients required only 12457+/-14738 microg/kg (p = 0.02) dopamine and 5112+/-7381 microg/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.