Long-Term Prognosis After Coronary Artery Calcification Testing in Asymptomatic Patients: A Cohort Study.

BACKGROUND

The extent of coronary artery calcification (CAC) and near-term adverse clinical outcomes are strongly related through 5 years of follow-up.

OBJECTIVE

To describe the ability of CAC scores to predict long-term mortality in persons without symptoms of coronary artery disease.

DESIGN

Observational cohort.

SETTING

Single-center, outpatient cardiology laboratory.

PATIENTS

9715 asymptomatic patients.

MEASUREMENTS

Coronary artery calcification scoring and binary risk factor data were collected. The primary end point was time to all-cause mortality (median follow-up, 14.6 years). Univariable and multivariable Cox proportional hazards models were used to compare survival distributions. The net reclassification improvement statistic was calculated.

RESULTS

In Cox models adjusted for risk factors for coronary artery disease, the CAC score was highly predictive of all-cause mortality (P < 0.001). Overall 15-year mortality rates ranged from 3% to 28% for CAC scores from 0 to 1000 or greater (P < 0.001). The relative hazard for all-cause mortality ranged from 1.68 for a CAC score of 1 to 10 (P < 0.001) to 6.26 for a score of 1000 or greater (P < 0.001). The categorical net reclassification improvement using cut points of less than 7.5% to 22.5% or greater was 0.21 (95% CI, 0.16 to 0.32).

LIMITATIONS

Data collection was limited to a single center with generalizability limitations. Only binary risk factor data were available, and CAC was only measured once.

CONCLUSION

The extent of CAC accurately predicts 15-year mortality in a large cohort of asymptomatic patients. Long-term estimates of mortality provide a unique opportunity to examine the value of novel biomarkers, such as CAC, in estimating important patient outcomes.

PRIMARY FUNDING SOURCE

None.