Coronary Artery Calcification in Older Adults with Minimal Clinical or Subclinical Cardiovascular Disease

Background: Coronary artery calcification (CAC) reflects the extent of coronary artery atherosclerosis. The extent of coronary artery calcification is not well described in older adults.

Objective: To determine the extent of CAC in older adults participating in a large population study of cardiovascular disease (CVD), especially those characterized as having minimal clinical or subclinical cardiovascular disease.

Design: An observational epidemiologic study.

Population: Participants in the Cardiovascular Health Study Cohort, mean age 78 years, who had electron beam computed tomography (EBT) scan of the heart (n = 133); included were 106 persons with no prior evidence of clinical or subclinical CVD.

Measurements: Total CAC score was measured using cardiac EBT. Cardiovascular disease and risk factors, as well as carotid ultrasound, electrocardiogram, echocardiogram, and ankle-arm index, had been measured previously to define subclinical disease. Previous cerebral magnetic resonance imaging was also evaluated.

Results: Overall, the CAC scores were higher in those with clinical cardiovascular disease or evidence of subclinical cardiovascular disease than in those with no evidence of disease. For the 106 participants without evidence of clinical or subclinical disease, the median score was 176, compared with 367 in those with subclinical disease and 923 in those with clinical CVD. Seventeen persons had scores of zero. There was little difference in risk factors across quartiles of CAC in the subgroup of 106 with prior characterization of minimal CVD despite the broad range of CAC scores. There was a higher proportion of those with white matter grade > or = 2 by magnetic resonance imaging among those with higher CAC scores (P = .025). Infarct-like lesions prevalence ranged from 12.5% in the lowest group to 47.1% in the highest CAC group (P = .019).

Conclusions: Older adults with evidence of clinical or subclinical CVD have higher total CAC scores. Though the extent of coronary artery calcification was lower in those with minimal evidence of CVD, the range was broad and not explained by CVD risk factors.