Minimally invasive coronary revascularization in women: A safe approach for a high-risk group

Purpose: Female gender has been shown to be an independent risk factor for mortality in coronary artery bypass graft (CABG) surgery. This report analy zes our early outcomes in 304 women who underwent off-pump coronary artery bypass (OPCAB) surgery at the Washington Hospital Center (Washington, DC) o ver the last 3 years to determine whether this is a safe approach for coron ary bypass in women. Methods: A retrospective review of 5,528 cases of CABG bypass (on-pump) and 840 cases of OPCAB surgery, from June 1996 to July 1999, was performed. Wo men accounted for 1,527 (27.6%) of the on-pump bypass cases and 304 (36.2%) of the OPCABs. All cases without cardiopulmonary bypass were included, wit h the majority of the most recent cases being multivessel revascularization . The data for analysis were obtained from our cardiac surgery database and included cases from all surgeons operating at the Washington Hospital Cent er, although the majority of off-pump cases were performed by only a few of these surgeons. Results: The two groups were similar with respect to urgent cases, redos, a nd other comorbities including preoperative congestive heart failure, perip heral vascular disease, transient ischemic attack (TIA), cerebral vascular accident, and previous myocardial infarction. The mean age for the two grou ps was similar, 67 years for the off-pump group and 66 years for the on-pum p group. The absolute number of all off-pump cases increased each year (fro m 175 to a total of 373), representing a corresponding increase in percenta ge of all coronary artery bypass procedures (from 9% to 16%). Of the total number of patients undergoing CABG, the percentage of women who underwent O PCAB doubled from 3% to 6% over the time period analyzed. The percentage of single-vessel cases in the off-pump group fell from 88% to 41% as multives sel bypasses became more routine However, the percentage of patients aged g reater than or equal to 75 years was greater for the off-pump group (30%) t han for the on-pump group (24%). Otherwise, the two groups differed only in diabetic disease (36% off-pump compared with 46% on-pump; p = 0.001) and p revious transcatheter therapy (38% off-pump compared with 29% on-pump; p = 0.003). Patients who had OPCABs received fewer postoperative transfusions ( 40%) than the on-pump group (59%; p < 0.001). The off-pump group also had f ewer neurological complications in the form of TIAs or strokes (0.3%) compa red with the on-pump group (3.5%; p = 0.001). The mortality rate was 2.3% o ff-pump versus 4.1% on pump but did not reach statistical significance in t his study (p = 0.12). Conclusion: Myocardial revascularization in women can be performed safely w ithout cardiopulmonary bypass. In our series, the mortality for women recei ving off-pump revascularization was lower than the on-pump cohorts despite an older age and higher incidence of diabetes. Although the absolute mortal ity rates did not reach statistical significance, we were encouraged that t he mortality rate for women operated on without CPB dropped to the mortalit y rate typically seen in men. We also observed a favorable tendency in the off-pump group for a shorter length of stay and a lower incidences of trans ient ischemic attacks, strokes, post-op bleeding, and blood transfusions. A larger series of patients with multivariate analysis and/or a prospective trial will need to be analyzed in order to confirm our findings.