Coronary calcium as a predictor of coronary events in four racial or ethnic groups
Detrano R, Guerci AD, Carr JJ, Bild DE, Burke G, Folsom AR, Liu K, Shea S, Szklo M, Bluemke DA, O'Leary DH, Tracy R, Watson K, Wong ND, Kronmal RA - New England Journal of Medicine, 2008
In a multi-ethnic cohort free of baseline cardiovascular disease, coronary- artery calcium (CAC) measured by CT was a strong, independent predictor of incident coronary heart disease across all four racial/ethnic groups. Relative to a CAC score of 0, the adjusted risk of a coronary event was about 7.73-fold higher for scores of 101-300 and 9.67-fold higher for scores above 300. CAC added predictive value beyond standard risk factors; this is a prognostic, risk-marker result rather than a test of any treatment.
Key findings
- Among 6722 adults free of clinical cardiovascular disease at baseline (MESA; 38.6% white, 27.6% Black, 21.9% Hispanic, 11.9% Chinese), coronary-artery calcium (CAC) measured by CT strongly and independently predicted incident coronary heart disease across all four racial/ethnic groups over a median 3.8 years.
- Relative to CAC of 0, the adjusted risk of any coronary event was 7.73-fold higher for CAC 101-300 and 9.67-fold higher for CAC >300 (P<0.001 for both).
- Each doubling of the calcium score raised major coronary event (MI or CHD death) risk by 15-35% and any coronary event risk by 18-39%.
- CAC added predictive value beyond standard risk factors, with no significant difference in predictive performance between the groups.
Effect measures
- Hazard Ratio: 7.73
- Hazard Ratio: 9.67
- Hazard Ratio: 1.15 to 1.35 per doubling of CAC score
- Hazard Ratio: 1.18 to 1.39 per doubling of CAC score
Why this evidence tier (High)
- Risk of bias:
- Large, well-characterized multi-ethnic prospective cohort (MESA) free of baseline CVD, with CT-measured CAC and adjudicated events. As an observational cohort it shows prediction/association, not a treatment effect.
- Precision:
- Many events (162 coronary, 89 major) and large hazard ratios with P<0.001; per-doubling estimates are tight across all four groups.
- Directness:
- Hard clinical coronary endpoints and a directly measured imaging marker (CAC) in a primary-prevention population.
- Consistency:
- Concordant across all four racial/ethnic groups and with the wider CAC prognostic literature, including Blaha 2016.
- Funding / COI:
- Supported by the U.S. National Heart, Lung, and Blood Institute (NHLBI), NIH (MESA contracts N01-HC-95159 through N01-HC-95169). No structured COI field was present for NEJM at the 2008 publication date; no disqualifying conflict surfaced.
High certainty that coronary-artery calcium independently predicts coronary events across diverse populations; a prognostic/risk-marker result, not a test of any treatment.
- Population:
- 6,722 adults (38.6% white, 27.6% Black, 21.9% Hispanic, 11.9% Chinese) free of clinical cardiovascular disease at baseline, from the Multi-Ethnic Study of Atherosclerosis (MESA), United States; median follow-up 3.8 years.
- Conflicts of interest:
- Supported by NHLBI/NIH (MESA contracts N01-HC-95159 through N01-HC-95169). No author conflict-of-interest statement is present in the PubMed/MEDLINE record (COI disclosure was not a structured NEJM field in 2008). Associated CommentsCorrections entries are editorial commentary and correspondence, not corrections. No retraction or erratum was found.
- Funding:
- U.S. National Heart, Lung, and Blood Institute (NHLBI), NIH (MESA contracts N01-HC-95159 through N01-HC-95169).
Limitations
- Observational cohort: CAC predicts events, but the study does not test whether any treatment based on CAC improves outcomes.
- Median follow-up was relatively short (3.8 years), so these are short-to-intermediate-term predictions.
- The statement of no significant difference in predictive power between groups is a faithful paraphrase of the full-text analysis rather than a verbatim abstract claim.