Contemporary mortality risk prediction for percutaneous coronary intervention: results from 588,398 procedures in the National Cardiovascular Data Registry

Abstract

Objectives: We sought to create contemporary models for predicting mortality risk following percutaneous coronary intervention (PCI).

Background: There is a need to identify PCI risk factors and accurately quantify procedural risks to facilitate comparative effectiveness research, provider comparisons, and informed patient decision making.

Methods: Data from 181,775 procedures performed from January 2004 to March 2006 were used to develop risk models based on pre-procedural and/or angiographic factors using logistic regression. These models were independently evaluated in 2 validation cohorts: contemporary (n = 121,183, January 2004 to March 2006) and prospective (n = 285,440, March 2006 to March 2007).

Results: Overall, PCI in-hospital mortality was 1.27%, ranging from 0.65% in elective PCI to 4.81% in ST-segment elevation myocardial infarction patients. Multiple pre-procedural clinical factors were significantly associated with in-hospital mortality. Angiographic variables provided only modest incremental information to pre-procedural risk assessments. The overall National Cardiovascular Data Registry (NCDR) model, as well as a simplified NCDR risk score (based on 8 key pre-procedure factors), had excellent discrimination (c-index: 0.93 and 0.91, respectively). Discrimination and calibration of both risk tools were retained among specific patient subgroups, in the validation samples, and when used to estimate 30-day mortality rates among Medicare patients.

Conclusions: Risks for early mortality following PCI can be accurately predicted in contemporary practice. Incorporation of such risk tools should facilitate research, clinical decisions, and policy applications.

Figure 1. Population Flow Diagram

Between January 2004 and March 2007, 600713 PCI admissions were recorded in the NCDR CathPCI Registry. Following exclusions, 588398 total patients were included in the overall model development and validation cohort.

Figure 2. a. Calibration for the Full Model among STEMI Patients in the Validation Sample b. Calibration for the Full Model among Patients without STEMI in the Validation Sample

Demonstrates observed versus predicted mortality estimates (and the 95% CI) for 10 equally sized risk groups of STEMI (2a) and NSTEMI (2b) patients, based on the full risk prediction model evaluated in the second validation sample.

Figure 2. a. Calibration for the Full Model among STEMI Patients in the Validation Sample b. Calibration for the Full Model among Patients without STEMI in the Validation Sample

Demonstrates observed versus predicted mortality estimates (and the 95% CI) for 10 equally sized risk groups of STEMI (2a) and NSTEMI (2b) patients, based on the full risk prediction model evaluated in the second validation sample.

Figure 3. Calibration of NCDR Bedside Risk Score in Validation Sample

Based on their predicted risk, patients are grouped into eight risk groups, using the full risk prediction model, and then plotted again the observed mortality rates for these in the second validation sample.