Abstract 3720: External Validation of Established Risk Adjustment Models for Procedural Complications after Percutaneous Coronary Intervention on an Independent Data Set

Abstract

We sought to validate the two risk adjustment models (Mayo Clinic,US & NWQIP,UK models) for in-hospital PCI complications on an independent data set of patients undergoing PCI. Methods: Between September 2002 and August 2006, 5034 consecutive PCI procedures (Validation set) were performed on a patient group characterized by a high incidence of AMI (16.1%) and cardiogenic shock (1.7%). Two external models of in-hospital complications (in-hospital death; Q-wave MI; emergent CABG; and CVA) after PCI, one developed by the North West Quality Improvement Programme (NWQIP; n = 9914) and the other by the Mayo Clinic (MC; n = 5463), were externally validated. Results: In this patient group, an overall in-hospital complication rate of 2% was observed. Multivariate regression analysis identified risk factors for in-hospital complications that were similar to the risk factors identified by the two external models. When fitted to the data set, both external models had an area under the ROC curve ≥ 0.85 (c index (95% CI), NWQIP; 0.86 (0.82, 0.9), MC; 0.87(0.84, 0.9)) indicating overall excellent model discrimination and calibration (Hosmer-Lemeshow test, p > 0.1). The NWQIP model was accurate in predicting in-hospital complications in different patient subgroups. Conclusions We have externally validated both models. Despite differences in variable selection, these predictive models yield comparable results when applied to patient groups in a different geographic population other than the one on which the original model was developed. These prediction rules can be useful for risk-adjustment analysis and for prognostication for individual patients.