Outcomes for Endocarditis Surgery in North America: A Simplified Risk Scoring System

Study Questions:

Using the Society of Thoracic Surgeons (STS) Adult Cardiac Surgery Database, can a simple risk scoring system be developed for patients who undergo surgery for infective endocarditis to identify areas for quality improvement?


From 2002 through 2008, 19,543 operations were performed for infective endocarditis. Logistic regression analysis related baseline characteristics to both operative mortality and a composite of mortality and major morbidity within 30 days. Points were assigned to each risk factor, and estimated risk was obtained by averaging events for all patients having the same number of points.


Overall unadjusted mortality was 8.2%, and complications occurred in 53%. Significant preoperative risk factors for mortality (associated points) were as follows: emergency, salvage status, or cardiogenic shock (17); preoperative hemodialysis, renal failure, or creatinine level less than 2.0 (12); preoperative inotropic or balloon pump support (10); active (vs. treated) endocarditis (10); multiple valve involvement (9); insulin-dependent diabetes (8); arrhythmia (8); previous cardiac surgery (7); urgent status without cardiogenic shock (6); noninsulin-dependent diabetes (6); hypertension (5); and chronic lung disease (5), with a C statistic of 0.7578 (all p < 0.001). Risk-adjusted mortality and major morbidity were unchanged over the course of the study. In the entire data set, mortality was better if ‘‘any valve’’ was repaired (odds ratio, 0.76; p = 0.0023).


Operative mortality for surgically treated infective endocarditis is substantially lower than reported in-hospital mortality rates for infective endocarditis. The described risk scoring system will help clinical decision-making in these complex patients.


Surgical intervention among patients with infective endocarditis is associated with the highest mortality of any valve disease, with reported rates of overall in-hospital mortality exceeding 20%. This study found an overall mortality rate of 8.2% among patients operated for infective endocarditis, possibly reflecting better patient selection compared to earlier reports, improved operative techniques and perioperative care, or selection bias in prior publications and/or in data used in the STS database. The preoperative hemodynamic condition of the patient was the single strongest predictor in this series of mortality and major morbidity after surgery for infective endocarditis, with emergency surgery, salvage operation, or cardiogenic shock associated with the worst outcomes. Surgical intervention remains an appropriate and effective treatment among selected patients with infective endocarditis; this scoring algorithm could be useful to help assess patient risk and aid in decision-making.

Clinical Topics: Cardiac Surgery, Heart Failure and Cardiomyopathies, Invasive Cardiovascular Angiography and Intervention, Prevention, Cardiac Surgery and Heart Failure, Acute Heart Failure, Hypertension

Keywords: Renal Dialysis, Shock, Cardiogenic, Renal Insufficiency, North America, Endocarditis, Hospital Mortality, Cardiac Surgical Procedures, Endocarditis, Bacterial, Hypertension, Hemodynamics, Lung Diseases

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