Patient Characteristics and Operative Details
A total of 293 cardiac surgical patients were included in this study with CPB time ≥ 300 minutes. Baseline patient demographics are summarized in Table 1 . Median age and body mass index were 62 years and 28.1 kg/m2, respectively. Patients were predominately of male sex and white race. The majority of patients were also of New York Heart Association class 1 symptoms (65.2%) and 32.4% had a prior history of heart failure. Median Society of Thoracic Surgeons predicted risk of mortality was 2.5% (IQR 1.3% – 4.7%). A total of 6 patients (2.0%) had preoperative mechanical support (4 intra-aortic balloon pump (IABP), 2 extracorporeal membrane oxygenation (ECMO)).
A breakdown of performed operations are displayed in Table 2 . The most common operation performed in this cohort was aortic root replacement (34.5%), followed by double valve procedure (23.6%) and combined coronary artery bypass grafting and aortic valve replacement (9.6%). Forty-four percent of cases were performed in an elective setting, while 20.5% were performed as an emergent and/or salvage procedure. A total of 116 (39.6%) cases were redo operations. Median CPB time in this cohort was 340.0 minutes (IQR 315.0 – 385.0 minutes), and median cross clamp time was 254.0 minutes (IQR 204.0 – 298.0 minutes). Median CPB time was longest in the combined CABG and aortic valve replacement group (350.5 minutes, IQR 325.5 – 397.5 minutes). IABP was utilized intraoperatively in 20.1% of cases, and ECMO was used intraoperatively in 7.2% of cases (Table 3 ). Postoperative IABP or ECMO were used in 6 (2.1%) and 2 (0.7%) cases, respectively. No patients received a ventricular assist device intraoperatively or postoperatively.