Bilateral versus Single Internal Thoracic Artery Grafting in Dialysis Patients with Multivessel Disease

Abstract

The purpose of our study was to compare mortality in dialysis patients undergoing bilateral internal thoracic artery (BITA) or single internal thoracic artery (SITA) grafting and to quantify the magnitude of the BITA grafting benefit for survival. Between January 2002 and December 2008, 656 consecutive patients underwent isolated coronary artery bypass grafting (99.1% by an off-pump technique). Fifty-six of these patients with chronic dialysis and multivessel disease were retrospectively compared with respect to surgical technique: BITA (n = 32) or SITA (n = 23) grafting. End points were all-cause and cardiovascular mortality (mean follow-up duration, 2.5 years). In an attempt to minimize the selection bias, we created propensity scores based on 13 preoperative factors that would affect the surgeon's decision about operative strategy; these factors were used for regression adjustment (C statistic, 0.914). There were no significant differences between the 2 groups with respect to age, sex, left ventricular ejection fraction, prevalence of diabetes mellitus and peripheral arterial disease, and logistic EuroSCORE. All patients under-went revascularization with the off-pump technique, with no conversion to cardiopulmonary bypass. All arterial conduits were harvested with a skeletonization technique in all cases. Except for 1 patient who received a SITA, internal thoracic arteries were used as in situ grafts in both groups. Complete revascularization was achieved in all patients. The 1-, 3-, and 5-year survival rates free from all-cause mortality for BITA grafting versus SITA grafting were 94% versus 73%, 72% versus 42%, and 52% versus 28%, respectively (P = .01, logrank test). For survival free from cardiovascular mortality, the respective rates were 100% versus 90%, 80% versus 77%, and 80% versus 58% (P = .06). After propensity score adjustment, BITA grafting was significantly associated with lower risks for all-cause mortality (hazard ratio, 0.27; 95% confidence interval, 0.09-0.81; P = .02) and cardiovascular mortality (hazard ratio, 0.20; 95% confidence interval, 0.04-0.93; P = .04). In situ skeletonized BITA grafting provides better long-term survival in dialysis patients with multivessel disease.