Unstable angina and non-ST segment elevation: surgical revascularization with different strategies.

OBJECTIVE

Unstable angina/non-ST elevation myocardial infarction (UA/NSTEMI) still causes significant hospital morbidity and mortality. We evaluated whether surgical outcome can be modified by different myocardial protection strategies.

METHODS

This was a prospective clinical study conducted in the cardiac surgery units of two university hospitals. Two hundred and sixty-two consecutive patients undergoing CABG for UA/NSTEMI between January 2002 and June 2004 were prospectively divided in three groups: 126 patients underwent on-pump CABG with antegrade blood cardioplegia (Group A); 67 underwent antegrade and retrograde blood cardioplegia (Group B); 69 off-pump CABG (Group C). Hospital outcome was analysed. Differences in outcome variables were detected with ANOVA; Tukey's multiple comparison test and Tamhane's T2 test were used when appropriate.

RESULTS

Group A showed higher mortality (P=.001; P=.014 vs. Group B; P=.003 vs. Group C) and perioperative myocardial infarction (P=.001; P=.016 vs. Group B; P=.05 vs. Group C). Hospital stay was shorter in Group B and Group C, compared to Group A (P=.005; P=.043 and P=.05, respectively). Group A required higher doses of inotropes compared to Group B and Group C (P=.0001; P=.0001 and P=.03, respectively), whereas Group B and Group C did not require any inotropic support at all (P=.0001; P=.002 and P=.001 vs. Group A, respectively). Total morbidity was higher in Group A (P=.006; P=.007 vs. Group B; P=.005 vs. Group C). Wall motion score index recovered only in Group B (P=.0001) and Group C (P=.001). Troponin I was higher in Group A at 12 h (P=.0001; P<.001 vs. Group B and Group C), 24 (P=.0001; P=.001 vs. Group B and Group C), 48 (P=.0001; P=.001 vs. Group B, P=.002 vs. Group C) and 72 h (P=.0001; P=.004 vs. Group B; P=.05 vs. Group C).

CONCLUSIONS

Isolated antegrade cardioplegia should be questioned in UA/NSTEMI. Outcome using off-pump revascularization was as good as that of combined antegrade and retrograde warm blood cardioplegia.