Performance of Prognostic Risk Scores in Heart Failure Patients: Do Sex Differences Exist?

Abstract

BackgroundSex differences in the performance of prognostic risk scores in heart failure (HF) patients have not previously been investigated. We examined the performance of 2 commonly used scores in predicting mortality and a composite end point consisting of ventricular assist device, heart transplantation, or mortality in women vs men with HF. MethodsThis was a retrospective study of 1,136 (25% women) consecutive ambulatory adult HF patients with reduced left ventricular ejection fraction (≤ 40%) followed at a single institution from 2000 to 2012. Discrimination, calibration, and absolute risk reclassification of the Seattle Heart Failure Model (SHFM) and the Meta-Analysis Global Group in Chronic Heart Failure (MAGGIC) score to predict 1- and 3-year outcomes were compared between women and men. ResultsAt 1- and 3-year follow-ups, 116 (22% women) and 231 (21% women) patients died, respectively. Survival was equal between sexes (P = 0.41). The SHFM and the MAGGIC score showed similar discriminatory capacity in women (c-statistics 0.84, 95% CI 0.77-0.92, and 0.74, 95% CI 0.64-0.83) and men (c-statistics 0.74, 95% CI 0.69-0.79, and 0.70, 95% CI 0.64-0.75). There was no difference in the predicted and observed 1-year mortality by the scores in both sexes. Compared with the SHFM, the MAGGIC score better reclassified 10% (95% CI 7%-14%) of women and 18% (95% CI 15%-20%) of men. At 3-year follow-up, similar results were seen for discrimination, whereas both scores overestimated mortality with more marked overestimation in women. The results were reproducible for the composite end point, with improved calibration at 3-year follow-up in both scores. ConclusionsOur findings support the use of the MAGGIC score in both women and men owing to better risk classification.