August 28, 2015 - Coronary artery calcification scores accurately predict 15-year mortality in a large cohort of asymptomatic patients, according to a study published in the Annals of Medicine.

The study was designed to determine the ability of CAC scores to predict long-term mortality in persons without symptoms of coronary artery disease. In a single-center, outpatient cardiology laboratory, researchers collected binary risk factor data on 9715 asymptomatic patients and measured CAC.

With the primary end point was time to all-cause mortality (median follow-up, 14.6 years), researchers looked at Cox models adjusted for risk factors for coronary artery disease, for which the CAC score was highly predictive of all-cause mortality. 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).

The authors concluded that 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.

Figure: Quantification of calcium score – calcium in bones is highlighted in pink, and calcium in coronary arteries in red.²

References:

1. Shaw LJ, Giambrone AD, Blaha MJ, etc. Long-Term Prognosis After Coronary Artery Calcification Testing in Asymptomatic Patients: A Cohort Study. Ann Intern Med. 2015;163(1):14-21. doi:10.7326/M14-0612.
2. CT Calcium Scoring. My VMC. http://www.myvmc.com/investigations/ct-calcium-scoring/.