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

Background: We aimed to elucidate current national multiarterial coronary bypass grafting practice patterns and assess perioperative outcomes.

Methods: Isolated 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).

Results: A 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.

Conclusions: Multiarterial 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.