Estimating the Risk of Cardiovascular Events in U.S. Veterans Using the SMART Risk Score.

BACKGROUND

Estimation of long-term risk for cardiovascular events using the SMART (Secondary Manifestations of Arterial Disease) risk score can be potentially valuable in devising risk mitigation strategies.

OBJECTIVES

The objective of this study was to apply the SMART risk score to compute the risk for major adverse cardiovascular events (MACE) in the U.S. Veteran patient population.

METHODS

We used the Veterans Affairs (VA) informatics and computing infrastructure to identify patients referred for an initial outpatient cardiology evaluation between the years 2003 and 2010 to estimate 10-year risk for composite MACE (all-cause death, ischemic stroke, and nonfatal myocardial infarction). Cox regression and survival curves were used to develop and validate the VA SMART score.

RESULTS

The study population included 472,702 patients (mean age 60 ± 8.9 years, 96% male) who were allocated into development (n = 94,091) and test cohorts (n = 378,611). The median follow-up time was 7.9 years (IQR: 6.0-9.9). The VA-SMART score allowed accurate estimation of MACE. Patients were stratified in low (<10%), moderate (10% to 20%), high (20% to 30%), and very high (≥30%) risk groups with observed events rates of 6.8%, 17.9%, 28.5%, and 49.5%, respectively, in the test cohort ( < 0.0001 for all intergroup comparisons). Most MACE events were all-cause death, with nonfatal myocardial infarction and stroke also being high, especially in the very high-risk group. The VA SMART score performed similar to other established risk prediction models (C-statistic = 0.67).

CONCLUSIONS

The VA SMART risk score can estimate the long-term risk of recurrent cardiovascular events in U.S. Veterans and could help implement individualized risk mitigation strategies.