Impact of Unstable Angina on Outcomes of Transmyocardial Laser Revascularization Combined With Coronary Artery Bypass Grafting

Abstract

For sole therapy transmyocardial laser revascularization (TMR), unstable angina has been demonstrated to be a significant independent predictor of operative mortality. The objective of this study was to investigate the preoperative risk profile of patients undergoing TMR plus coronary artery bypass graft surgery (CABG) and to determine the impact of unstable angina on outcomes. Using The Society of Thoracic Surgeons National Cardiac Database from 1998 to 2003, 5,618 patients underwent TMR plus CABG. These patients were compared with 932,715 patients who underwent CABG only operations. The TMR plus CABG patients had a significantly higher incidence of diabetes (50% versus 34%), renal failure (7% versus 5%), peripheral vascular disease (20% versus 16%), reoperative surgery (26% versus 9%), three-vessel coronary artery disease (80% versus 71%), hyperlipidemia (73% versus 62%; p < 0.001 for all comparisons). The incidence of preoperative unstable angina was similar (46% versus 47%). The unadjusted perioperative mortality was 3.8% for TMR plus CABG patients. When unstable angina patients were removed, the observed mortality for TMR plus CABG was decreased to 2.7%. It is likely that patients who undergo TMR plus CABG have a higher prevalence of diffuse coronary disease based on their preoperative demographics. Despite the increased risk associated with such anatomy, the mortality rate was not significantly increased when TMR was added to CABG in an effort to provide a more complete revascularization. As was noted from the outcomes of sole therapy TMR, in unstable angina patients, TMR plus CABG carries a higher risk, but this risk is not significantly different from that of such patients treated with CABG alone.