Interhospital failure to rescue after coronary artery bypass grafting

We evaluated whether interhospital variation in mortality rates for coronary artery bypass grafting was driven by complications and failure to rescue.

An observational study was conducted among 83,747 patients undergoing isolated coronary artery bypass grafting between July 2011 and June 2017 across 90 hospitals. Failure to rescue was defined as operative mortality among patients developing complications. Complications included the Society of Thoracic Surgeons 5 major complications (stroke, surgical reexploration, deep sternal wound infection, renal failure, prolonged intubation) and a broader set of 19 overall complications. After creating terciles of hospital performance (based on observed:expected mortality), each tercile was compared on the basis of crude rates of (1) major and overall complications, (2) operative mortality, and (3) failure to rescue (among major and overall complications). The correlation between hospital observed and expected (to address confounding) failure to rescue rates was assessed.

Median Society of Thoracic Surgeons predicted mortality risk was similar across hospital observed:expected mortality terciles (P = .831). Mortality rates significantly increased across terciles (low tercile: 1.4%, high tercile: 2.8%). Although small in magnitude, rates of major (low tercile: 11.1%, high tercile: 12.2%) and overall (low tercile: 36.6%, high tercile: 35.3%) complications significantly differed across terciles. Nonetheless, failure to rescue rates increased substantially across terciles among patients with major (low tercile: 9.1%, high tercile: 14.3%) and overall (low tercile: 3.3%, high tercile: 6.8%) complications. Hospital observed and expected failure to rescue rates were positively correlated among patients with major (R² = 0.14) and overall (R² = 0.51) complications.

The reported interhospital variability in successful rescue after coronary artery bypass grafting supports the importance of identifying best practices at high-performing hospitals, including early recognition and management of complications.