Multiple arterial grafts : Radial versus right internal thoracic arteries. Commentary

Background-Left internal thoracic artery (LITA) grafts to the left anterior descending coronary artery (LAD) during coronary bypass surgery (CABG) have greater patency rates than saphenous vein grafts and reduce long-term cardiac morbidity and mortality rates. The benefits of multiple versus single arterial grafts and the role of different arterial conduits with respect to short- and medium-term outcome remains controversial. The purpose of this study was to compare the perioperative and intermediate-term results of: (1) patients receiving 2 arterial grafts versus 1 arterial graft and (2) patients receiving a right internal thoracic artery (RITA) versus a radial artery (RA) as the second arterial graft. Methods and Results-Retrospective analysis of prospectively gathered data on consecutive patients undergoing isolated CABG at our institution between 1989 and 1996 was conducted. The first section of the study compared outcomes for I arterial graft (LITA to LAD, n=2333) versus 2 arterial grafts (LITA + RA or LITA + RITA, n=378). The second section of the study compared outcomes for the RITA (n=132) versus the RA (n=171) as second arterial grafts since 1992, when the radial series was initiated. Part I: By multivariable stepwise logistic regression, the use of 1 arterial graft was associated with an increased incidence of perioperative cardiac morbidity and mortality (odds ratio 2.2, 95% confidence interval 1.4 to 3.3), with the use of our current patient selection criteria. Double-arterial graft patients had a nonsignificant trend toward increased intermediate-term actuarial survival (P=0.12) and cardiac event-free survival (P=0.09). Part II: Comparison of preoperative demographics revealed a higher incidence of diabetes (27% vs 11%, P<0.001), peripheral vascular disease (16% vs 8%, P=0.03), and elderly age (13% vs 2%, P=0.001) in patients receiving an RA versus those receiving a RITA as the second arterial graft. Perioperative outcome analysis revealed a decreased intensive care unit stay in the RA versus RITA group (median 30.4 vs 36.2 hours, respectively, P=0.005) but no significant difference in hospital length of stay. There was no significant difference in perioperative mortality or cardiac morbidity rates. RITA patients had a higher incidence of sternal wound infection (5.3% vs 0.6%, P=0.01), however, and tended to have increased blood product transfusion rates (51% vs 40%, P=0.06). Conclusions-The use of 2 arterial grafts is safe, with a reduction in perioperative cardiac morbidity or mortality rates compared with I arterial graft after adjustment for other risk variables. When comparing RITA to RA as second arterial grafts, patients receiving an RA have a lower incidence of sternal wound infection and decreased transfusion requirements, with no difference in perioperative or intermediate-term cardiac morbidity or mortality rates.