Multiarterial Coronary Artery Bypass Grafting Practice Patterns in the United States: Analysis of The Society of Thoracic Surgeons Adult Cardiac Surgery Database

Abstract

BackgroundWe aimed to elucidate current national multiarterial coronary bypass grafting practice patterns and assess perioperative outcomes. MethodsIsolated primary nonemergent/nonsalvage coronary artery bypass grafting patients with at least 1 internal thoracic artery and 2 or more grafts in The Society of Thoracic Surgery Adult Cardiac Surgery Database (2018-2019) were divided into 3 cohorts: single-arterial, bilateral internal thoracic artery (BITA), and radial artery multiarterial grafting. Observed-to-expected ratios based on 2017 Society of Thoracic Surgery risk models were derived for 30-day perioperative mortality, composite major morbidity and mortality, and deep sternal wound infections for each grafting group overall and as a function of institutional multiarterial case volumes per study period: low (<10), intermediate (11-30), and high (>30). ResultsA total of 281,515 patients (BITA, 15,663 [5.6%]; radial, 23,905 [8.5%]) at 1013 centers showed distinct geographic grafting patterns: BITA and radial multiarterial grafting rates were lowest in the South (4% and 6%, respectively) and highest in the Northeast (9% and 11%, respectively). The median institutional number of BITA and radial cases per study period was 4 and 7, with only 14% and 21% of institutions performing >30 BITA and radial multiarterial cases per study period, respectively. The observed-to-expected mortality for single-arterial bypass grafting was similar to multiarterial: single-arterial, 1.00 (95% CI, 0.98-1.03); BITA, 0.98 (95% CI, 0.84-1.13; P = .711); and radial, 0.96 (95% CI, 0.86-1.07; P = .818). Observed-to-expected mortality and composite major morbidity and mortality were lower at high vs low multiarterial case-volume centers: 0.91 (95% CI, 0.75-1.08) vs 1.30 (95% CI, 0.89-1.79; P = .048) and 1.06 (95% CI, 0.99-1.13) vs 1.51 (95% CI, 1.32-1.71; P < .001), respectively, for BITA, and 0.82 (95% CI, 0.87-1.30) vs 1.67 (95% CI, 1.21-2.21; P < .001) and 0.91 (95% CI, 0.93-1.08) vs 1.42 (95% CI, 1.24-1.61; P < .001), respectively, for radial. ConclusionsMultiarterial bypass grafting remains underused and limited to select centers. Worse outcomes at low-volume BITA and radial institutions document a case-volume outcomes effect. Additional studies are warranted to improve multiarterial outcomes at low-volume institutions.