Background: Coronary calcification detected by electron beam tomography may improve cardiovascular risk prediction. The technique is particularly promising in the elderly because the predictive power of cardiovascular risk factors weakens with age. We investigated the prognostic value of coronary calcification for cardiovascular events and mortality in a general, asymptomatic population of elderly subjects.
Methods and results: From 1997 to 2000, electron beam tomography scanning to assess coronary calcification was performed in subjects of the population-based Rotterdam Study. Risk factors were measured by standardized procedures. Coronary calcium scores were available for 1795 asymptomatic participants (mean age, 71 years; range, 62 to 85 years). During a mean follow-up of 3.3 years, 88 cardiovascular events, including 50 coronary events, occurred. The risk of coronary heart disease increased with increasing calcium score. The multivariate-adjusted relative risk of coronary events was 3.1 (95% CI, 1.2 to 7.9) for calcium scores of 101 to 400, 4.6 (95% CI, 1.8 to 11.8) for calcium scores of 401 to 1000, and 8.3 (95% CI, 3.3 to 21.1) for calcium scores >1000 compared with calcium scores of 0 to 100. The predictive value in subjects >70 years of age was similar. Risk prediction based on the cardiovascular risk factors improved when coronary calcification was added.
Conclusions: Coronary calcification is a strong and independent predictor of coronary heart disease, also in the elderly. Coronary calcification improves prediction of coronary events based on cardiovascular risk factors. Risk stratification by assessment of coronary calcification may have an important role in the primary prevention of coronary heart disease events in the elderly.