Risk Models Developed to Predict Cardiac and Noncardiac Mortality After PCI

September 10, 2015—Daniel P. Spoon, MD, et al sought to develop novel risk models to predict cardiac and noncardiac long-term mortality after percutaneous coronary intervention (PCI) because current risk models for predicting long-term mortality after PCI are restricted to all-cause mortality. The investigators’ report was published online ahead of print in Circulation: Cardiovascular Intervention.

As summarized in Circulation: Cardiovascular Interventions, the investigators retrospectively evaluated patients who underwent index PCI at the Mayo Clinic from 2003 to 2008. Long-term deaths were ascertained through scheduled prospective surveillance. Cause of death was determined via telephone interviews, medical records, and autopsy reports. 

Fine-Gray extension of Cox proportional hazards model was used to model cause-specific cumulative incidence. Candidate variables and interactions were chosen a priori, without variable selection methods. Resulting models were mapped to an integer-based risk score. 

The study was composed of 6,636 patients followed up over a median of 62 months (25th, 75th percentiles: 45, 77 months). There were 1,488 deaths, 518 (35%) cardiac, 938 (63%) noncardiac, and 32 (2%) unknown.

The 5-year predicted cardiac mortality ranged from 0.6% to 97%, with a corrected c-statistic of 0.82. Risk factors for cardiac death included age, body mass index, ejection fraction, and history of congestive heart failure. The integer score for noncardiac death included age, medicine index, body mass index, current smoker, noncardiac Charlson index and cardiac Charlson index, and accommodated significant age-based interactions for smoking and the two Charlson indices. The investigators in Circulation: Cardiovascular Interventions reported that predicted noncardiac mortality at 5 years ranged from 0.2% to 81%, with a corrected c-statistic of 0.77.