Predictors of short- and long-term outcome after open cardiac surgery in a high-volume referral tertiary hospital: the role of surgical team caseload

Abstract

Very few studies have investigated the role of surgeon and anesthesiologist caseloads and high-sensitive troponin I (hs-TnI) on short- and long-term outcomes in cardiac surgery. In this study we assessed the relationship between perioperative hs-TnI measurements with 1-year mortality and major cardiovascular events (MACE) at 30 days as a function of surgeon and anesthesiologist volume experience. This is a single center, prospective observational study in a tertiary high-volume hospital enrolling 1000 consecutive adult patients undergoing open cardiac surgery. All patients were managed according to a standardized protocol, as per routine practice. Exclusion criteria were age <18, no written consent, ongoing myocardial infarction, preoperative hs-TnI ≥300 ng/L, salvage cardiac surgery, isolated thoracic aortic surgery or implantation of a ventricular assist device. At the multivariable analysis, lowest hematocrit during cardiopulmonary bypass [Odd ratio (OR): 0.81; 95% confidence intervals (CI): 0.74–0.92], preoperative activated thromboplastin time (OR: 1.04; 95% CI: 1.01–1.08), expert anesthesiologist (OR: 22.8; 95% CI: 1.73–301.87), post-operative intra-aortic balloon pump (OR: 5.20: 95% CI: 1.62–16.44), post-operative venous-arterial-extracorporeal membrane oxygenator (OR: 83.93; 95% CI: 4.95–1436.55), transfusion (OR: 10.17; 95% CI: 2.41–42.94) and MACE (OR: 3.93; 95% CI: 1.28–12.18) were independently associated with 1-year mortality [Hosmer and Lemeshow chi-test = 4.82; p = 0.77; AUC of the model corrected for optimism: 0.92 (95% CI: 0.89–0.94)]. We found that surgeons and anesthesiologists were not independent predictors of MACE at 30 days. The hs-TnI, measured at several time points, was not effective in predicting 1-year mortality or MACE at 30 days. Anesthesiologist- and surgeon-related annual case volume did not affect MACE at 30 days, while 1-year mortality was independently associated with anesthesiologist providers with the highest caseload.