Comparison of Three Contemporary Surgical Scores For Predicting All-Cause Mortality Of Patients Undergoing Percutaneous Mitral Valve Repair With The MitraClip System: Insights From The Multicenter GRASP-IT Registry

Background: There is a lack of knowledge on risk stratification for Mitraclip patients. Methods: To explore the adaptability of three contemporary surgical scores (Logistic EuroSCORE [LES], EuroSCORE II [ESII] and Society of Thoracic Surgeons Predicted Risk of Mortality [STS-PROM] for prediction of mortality after percutaneous mitral valve repair with the Mitraclip system. Results: A statistically significant gradient in the distribution of mortality was observed at all time points with ESII, at 2 years with LES and at 2 and 3 years with STS-PROM. ESII had the best discrimination at 30 days (c-statistic 0.80), which remained acceptable at later follow-up, being significantly superior to that of LES at each time point (P¼0.003 at 30 days, P¼0.005 at 1 year, P¼0.011 at 2 years, P¼0.029 at 3 years). Compared with STS-PROM (c-statistic 0.62), ESII showed better discrimination at 30 days (P¼0.023). All scores over-predicted the risk of mortality at 30 days and were miscalibrated at 2 and 3 years. At 1 year, there was a good agreement between the observed and predicted probabilities for ESII and STS-PROM, whereas LES remained over-predictive. ESII showed the best global accuracy at 30 days and 1 year, whereas no notable differences were noted versus LES and STS-PROM at 2 and 3 years. Conclusions: In the absence of specific tools for risk stratification of patients undergoing MitraClip implantation, ESII holds favorable prognostic characteristics, which make it a valid surrogate.