Abstract 13381: The Intermountain Risk Score Predicts Mortality and Cardiovascular Events among Coronary Disease Patients Treated by Percutaneous or Medical Interventions

Abstract

Background: The Intermountain Risk Score (IMRS) is a clinical decision tool computed from inexpensive lab tests (BMP and CBC) and predicts mortality in medical, cath lab, and general populations. It is unknown if it retains predictive ability in higher-acuity coronary artery disease (CAD) subpopulations. The association of IMRS with mortality and myocardial infarction (MI), stroke, and repeat revascularization was evaluated in CAD patients undergoing percutaneous coronary intervention (PCI) and in those treated with medical therapy only.

Methods: IMRS values were calculated using all components of the BMP and CBC in the two cohorts of patients. A maximum of 18.4 years of follow-up was available in both cohorts, with an average of 8.4 years in the PCI cohort and 8.7 years in the medical therapy cohort. Survival analysis used Cox Regression adjusting for 18 co-variables. Mortality data were gathered from hospital records, Utah death certificates, and Social Security records. MI, stroke, and revascularization data were drawn from electronic medical records.

Results: In the PCI population, IMRS strongly predicted death among females and males (table), with areas under the curve (AUCs) of 0.703 and 0.681, respectively. IMRS also predicted MI in males and stroke in females, but did not predict repeat revascularization in either sex (p>0.22). Subanalysis in PCI patients stratified by ACS or stable presentation had similar results. In the medical therapy-only population, death was also predicted by IMRS among females and males (table, AUCs=0.680, 0.672). IMRS also predicted MI in males but did not predict stroke in either sex. Repeat revascularization was not assessed for medical-only since their initial therapy was to not receive revascularization.

Conclusions: IMRS significantly predicts mortality in CAD patients receiving either PCI or medical therapy only. Due to its low incremental cost but high predictive ability, IMRS should be evaluated for clinical application.