Validation of National Cardiovascular Data Registry Risk Models for Mortality, Bleeding and Acute Kidney Injury in Interventional Cardiology at a German Heart Center

Background And Purpose: The National Cardiovascular Data Registry (NCDR) risk scores for mortality, bleeding and acute kidney injury (AKI) are accurate outcome predictors of coronary catheterization procedures in North American populations. However, their application in German clinical practice remained elusive and we thus aimed to verify their use.

Methods: NCDR scores for mortality, bleeding and AKI and corresponding clinical outcomes were retrospectively assessed in patients undergoing catheterization for ST-segment elevation myocardial infarction (STEMI), non-ST-segment elevation myocardial infarction (NSTEMI) or for elective coronary procedures at a German Heart Center from 2014 to 2017. Risk model performance was assessed using receiver-operating-characteristic curves (discrimination) and graphical analysis/logistic regression (calibration).

Results: A total of 1637 patients were included, procedures were performed for STEMI (565 patients, 34.5%), NSTEMI (572 patients, 34.9%) and elective purposes (500 patients, 30.5%); 6% (13% of STEMI and 5% of NSTEMI patients) presented in cardiogenic shock and 3% with resuscitated cardiac arrest. Radial access was used in 38% of procedures and cross-over was necessary in 5%; PCI was performed in 60% of procedures. In-hospital mortality was 6.3% (STEMI 14.5%; NSTEMI 3.7%; elective 0%) and major bleedings occurred in 5.6% (STEMI 10.6%; NSTEMI 5.4%; elective 0.2%); AKI was detected in 18.1% of patients (STEMI 23.7%; NSTEMI 27.3%; elective 1.4%), amounting to KDIGO stage I/II/III in 11.5%/3.5%/3.2%. NCDR risk models discriminated very well for mortality [AUC 0.93 with 95% confidence interval (CI) 0.91-0.95] and well for major bleeding (AUC 0.82, CI 0.78-0.86) and any AKI (AUC 0.83, CI 0.81-0.86). Discrimination in the subgroup of patients with PCI was comparable (mortality: AUC 0.90; major bleeding: AUC 0.78; any AKI: AUC 0.79). However, calibration showed considerable underestimation of mortality and AKI in high-risk patients, while major bleeding was consistently overestimated (Hosmer-Lemeshow p < 0.02 for all outcomes).

Conclusions: The NCDR risk models showed excellent performance in discriminating high-risk from low-risk patients in contemporary German interventional cardiology. Model calibration for adverse event probability prediction, however, is limited and demands recalibration, especially in high-risk patients.