Coronary calcium as a predictor of coronary events in four racial or ethnic groups.
Level 3 - non-randomized controlled study
Prospective multi-ethnic cohort study
PubMed 18367736 · doi:10.1056/NEJMoa072100
What was done
Computed tomography scanning for coronary-artery calcium and baseline cardiovascular risk factors were evaluated in 6,722 men and women without clinical cardiovascular disease at entry. The cohort included 38.6% white, 27.6% black, 21.9% Hispanic, and 11.9% Chinese participants. Cohort members were followed for a median of 3.8 years for incident coronary events and major coronary events (myocardial infarction or coronary heart disease death).
What was found
During follow-up, 162 coronary events occurred, including 89 major events. Compared with a calcium score of 0, adjusted risk of a coronary event increased by a factor of 7.73 for scores of 101 to 300 and 9.67 for scores above 300 (P<0.001 for both). Across the four racial and ethnic groups, doubling the calcium score increased major coronary event risk by 15% to 35% and any coronary event risk by 18% to 39%. Adding calcium score to standard risk factors improved receiver-operating-characteristic area under the curve across all groups without major between-group differences in predictive value.
Why it matters
This establishes that coronary calcium scoring improves risk stratification beyond standard cardiovascular risk factors across racially and ethnically diverse populations, rather than only in white cohorts.
Limits
Follow-up was relatively short (median 3.8 years), yielding a modest total event count (162 total events, 89 major events) across four subgroups. Chinese participants represented only 11.9% of the cohort. Confidence intervals and specific event breakdowns by subgroup were not reported in the abstract.
Cited by
- contradicts Coronary artery calcification (a high calcium score) represents stabilized plaque unlikely to rupture, whereas soft plaque is the primary driver of acute arterial blockage and heart attacks.