Association of hospital volume with outcomes for reoperative coronary artery bypass grafting.

Abstract

Outcomes following reoperative coronary artery bypass graft surgery are widely underexplored. Evaluating a contemporary national cohort, we assessed acute clinical and financial sequelae following reoperative coronary artery bypass graft surgery at the patient and hospital levels. The 2016-2021 Nationwide Readmissions Database was queried to identify all adult (≥18 years) hospitalizations for elective isolated coronary artery bypass graft surgery. Patients with a history of coronary artery bypass graft surgery were categorized as ReOp (others: Non-ReOp). Centers in the highest quartile were considered high-volume centers. Multivariable regression models were built to assess the independent association of ReOp with clinical and financial outcomes. Of ∼470,546 patients, 5.0% were classified as ReOp. On average, ReOp was older (70 [63-76] vs 67 years [60-73], P < .001), more often female (26.7 vs 21.7%, P < .001), and of a higher Elixhauser comorbidity index (5 [4-7] vs 4 [3-5], P < .001). Following risk adjustment, ReOp was linked with comparable likelihood of in-hospital mortality (adjusted odds ratio 0.87, 95% confidence interval 0.74-1.03). However, ReOp faced greater odds of infection (adjusted odds ratio 1.72, 95% confidence interval 1.60-1.85), thromboembolism (1.85, 1.45-2.36), and stroke (1.35, 1.12-1.64). ReOp was also linked with greater costs (β +$9,845, 95% CI 8,888-0,802). At high-volume centers, 5.1% of coronary artery bypass graft surgery recipients were ReOp. Reoperation was associated with greater adjusted odds of major complications (adjusted odds ratio 1.19, 95% confidence interval 1.12-1.27) and increased hospitalization expenditures (β +$6,782, 95% confidence interval 5,725-7,837). The increased risk of facing major perioperative outcomes following reoperative coronary artery bypass graft surgery persists at centers despite case volume. Further studies are needed to develop optimal perioperative care pathways for these patients.