Late operating room start times impact mortality and cost for nonemergent cardiac surgery

Background There is growing concern over the effect of starting non-emergent cardiac surgery later in the day on clinical outcomes and resource utilization. Our objective was to determine the differences in patient outcomes for starting non-emergent cardiac surgery after 3 pm. Methods All non-emergent cardiac operations performed at a single institution from July 2008 to 2013 were reviewed. Cases were stratified based on "early start" or "late start," defined by incision time before or after 3 pm. Rates of observed and risk-adjusted mortality, major complications, and costs were compared on a univariate basis for all patients and by multivariable linear and logistic regression for patients with a valid The Society of Thoracic Surgeons (STS) Predicted Risk of Mortality (PROM). Results A total of 3,395 non-emergent cardiac operations were reviewed, including 368 late start cases. Compared with cases starting earlier, mortality was significantly higher for patients undergoing late operations (5.2% vs 3.5%, p = 0.046) despite similar preoperative risk (STS PROM 3.8% vs 3.3%) and major complication rates (18.2% vs 18.3%). Costs were 8% higher with late start cases ($51,576 vs $47,641, p < 0.001). After controlling for case type, surgeon, year, and risk, late cases resulted in higher mortality (odds ratio 2.04, p = 0.041) despite shorter operative duration (16 minutes, p < 0.001). Conclusions Starting non-emergent cardiac cases later in the day is associated with 2 times higher absolute and risk-adjusted mortality. These data should be carefully considered, not only by surgeons and patients but also in the context of the operating room system when scheduling non-emergent cardiac cases.