Complete myocardial revascularization using arterial grafts only in patients with unstable angina: impact on early outcome

Abstract

Objective: The aims of this study were 1) to assess early clinical outcomes for patients with unstable angina (UA) who undergo urgent/emergent coronary artery bypass grafting (CABG); and 2) to evaluate the feasibility and safety of complete revascularization using strictly arterial grafts in this patient group.

Patients and methods: Between September 2001 and May 2005, a total of 961 patients underwent CABG at our center. One hundred and sixty-seven (17.4 %) of these individuals underwent urgent or emergent CABG because of UA, and 794 (82.6 %) underwent elective CABG for stable angina (SA). Of the 167 patients with UA, 59 (35.3 %) underwent complete revascularization using arterial grafts only (AO subgroup: internal thoracic arteries and radial arteries) and the other 108 received a combination of arterial and venous grafts (AV subgroup: 1 internal thoracic artery plus saphenous vein grafts).

Results: The UA group had a significantly higher proportion of women and a significantly higher rate of left main coronary artery disease than the SA group ( P = 0.016 and P = 0.0001, respectively). Cardiopulmonary bypass time was significantly longer in the UA group ( P = 0.01). Higher proportions of the UA group required inotropic support ( P = 0.001), intra-aortic balloon pump support ( P = 0.001), and re-exploration for bleeding or cardiac tamponade ( P = 0.005). This group also had a significantly longer mean time on mechanical ventilation ( P = 0.001) and a longer mean intensive care unit stay ( P = 0.01). The rates of operative mortality (first 30 days) in the SA and UA groups were 1.8 % and 6 %, respectively ( P = 0.001). There were no statistical differences between the AO and AV subgroups with respect to any of the preoperative or intraoperative findings. The AO group had a significantly shorter mean intensive care unit stay than the AV group ( P = 0.05). The AV group had a roughly fivefold higher operative mortality than the AO group (8.3 % vs. 1.7 %, respectively), but this difference was not statistically significant ( P = 0.17).

Conclusion: Urgent or emergent CABG in the setting of UA is associated with increased but acceptable rates of mortality and morbidity. Complete myocardial revascularization using arterial grafts only (combinations of internal thoracic and radial arteries) is feasible and safe in this patient group.