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

Ann Intern Med. 2015 Jul 7;163(1):14-21. doi: 10.7326/M14-0612.


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.

Publication types

  • Observational Study

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Asymptomatic Diseases / mortality*
  • Cause of Death
  • Coronary Artery Disease / diagnostic imaging
  • Coronary Artery Disease / mortality*
  • Female
  • Follow-Up Studies
  • Humans
  • Male
  • Middle Aged
  • Prognosis
  • Proportional Hazards Models
  • Radiography
  • Risk Factors