Development and validation of a nomogram predicting all-cause mortality for patients with an implantable cardioverter-defibrillator

Abstract

Abstract Background For patients with high risk of sudden cardiac death, despite the benefits of an implantable cardioverter defibrillator (ICD), some patients are still at a high risk of death. Death risk assessment of ICD patients is beneficial to the clinical management of such patients. Purpose The purpose of this study was to develop and validate a nomogram predicting all-cause mortality for patients with an ICD. Methods We retrospectively analyzed the data of multicenter ICD registration study (SUMMIT study) from 2010 to 2014 in China. A total of 617 ICD patients from regions where the enrollment ranked top five formed a development cohort. The physical activity monitored by ICD and clinical data were collected. Univariate and multivariate COX regression analyses were used to screen mortality predictors and construct the nomogram. The performance of nomogram was evaluated by the C index and the calibration curve. A total of 196 ICD patients from other regions formed a validation cohort, and the nomogram constructed by the development cohort was further evaluated in the verification cohort. Results In the development cohort, physical activity, diabetes and left ventricular end-diastolic diameter were selected as mortality predictors by univariate and multivariate proportional hazard model analysis. The nomogram was constructed by these three factors. The C index of the nomogram was 0.80 (95% confidence interval, 0.75-0.84). The calibration curve showed that the predicted survival probability of the nomogram was in good agreement with the actual survival probability. In the validation cohort, the C index of the nomogram was 0.74 (95% confidence interval, 0.64-0.84), and the calibration curve still maintained good consistency. Conclusion Our study develops and validates a nomogram predicting all-cause mortality for patients with an ICD by integrating the physical activity monitored by ICD and clinical data. The nomogram performs well and can provide personalized death risk assessment for ICD patients.Figure 1Figure 2