Risk stratification in heart surgery - do risk scores facilitate the decision for or against surgery?

Various risk scores have been developed for the assessment of operative ris k in cardiac surgery. Although risk stratification has been acknowledged as a useful tool to analyze trends in therapy and changes in patient populati ons, its relevance in assessing the indication for surgery has been questio ned. It was the goal of this prospective study to compare 6 common risk sco res with regard to the predictive value for mortality in individual patient s. Between September 1998 and February 1999 all adult patients undergoing hear t surgery were prospectively scored according to the following scores: init ial Parsonnet, Cleveland Clinic, French, Euro, Pens, and the Ontario Provin ce Risk score. Early lethality was assessed within 30 days postoperatively. Follow-up was completed in 504 patients. With the exception of the Ontario Province Risk score, lethality in the hig h risk group was overestimated by all scores, whereas lethality in low to m oderate risk groups was underestimated by several scores. Mean scores of su rviving and deceased patients showed a broad overlap with high standard dev iations. Preoperative risk scores are effective tools for stratification of patient populations and the analysis of surgical outcome. With the aid of risk scor es, operative risk can be sufficiently predicted for patient populations or subpopulations. The Euro score best predicted the outcome of our patients. However, when the indication for surgery is to be determined in an individu al patient, risk scores should be only considered as an orientation in the decision process.