Risk factors for early mortality after valve surgery in Europe in the 1990s: lessons from the EuroSCORE pilot program

The characteristics of valve surgery are evolving. The study aim was to explore its demographics and risk factors in Europe in the 1990s, using the EuroSCORE database.

For the EuroSCORE program, information on 98 variables regarding risk factors, procedures and outcome were collected for 5,672 patients undergoing valve surgery under cardiopulmonary bypass in 128 European centers. Bivariate (i.e. Mann-Whitney test or chi-square when appropriate), then logistic regression analyses were carried out to identify risk factors for early mortality. The predictive value of EuroSCORE was analyzed using the Hosmer-Lemershow test and by computing the area under the receiver operating characteristic (ROC) curve.

Aortic valve stenosis was the most common diagnosis (47.6%), whilst mitral valve surgery accounted for 42% of procedures. Coronary surgery was performed concomitantly in 21% of cases. Hospital mortality was 6.1%. Predictive factors for early mortality were: age (p = 0.0001), preoperative serum creatinine >200 micromol/l (p = 0.014), previous heart surgery (p = 0.0001), poor left ventricular function (p = 0.008), chronic congestive heart failure (p = 0.0001), pulmonary hypertension (p = 0.0001), active acute endocarditis (p = 0.0001), emergency procedure (p = 0.05), critical preoperative status (p = 0.0001), tricuspid surgery (p = 0.015), aortic and mitral surgery (p = 0.002), combined thoracic surgery (p = 0.0001), and combined coronary surgery (p = 0.0001). The predictive value of EuroSCORE for mortality was good (area under the ROC curve = 0.75).

The 'valve' subset of the EuroSCORE database provides an instant picture of European valve surgery in the 1990s that can be used either for individual assessment, or for country- or institution-based epidemiological studies of risk factors and practices.