Subclinical coronary atherosclerosis and resting ECG abnormalities in an unselected general population

OBJECTIVES: Exposure to cardiovascular (CV) risk factors may result in coronary atherosclerosis and myocardial disease, which is reflected in the extent of coronary artery calcification (CAC) and resting ECG abnormalities, respectively. We studied the association of CAC with ECG abnormalities in a general population without myocardial infarction or revascularization.

METHODS: The total cohort of 4814 subjects (45-75 years) were randomly selected from the general population for the Heinz Nixdorf Recall Study, an ongoing study designed to assess the prognostic value of modern risk stratification methods. In addition to measuring standard risk factors, digitized resting ECGs and the EBT-based Agatston score were obtained. Subjects were separated into those without (n=1929) and with CV disease (CVD) or treated risk factors (tRF) (n=2558).

RESULTS: In both groups, a positive CAC-score was more frequent and CAC-scores were higher in men and women with ECG abnormalities as compared to those with normal ECGs (p<0.05 each). In persons without CVD/tRF, a CAC > or =75th percentile was more frequent in those with LVH (42.4%) and QTc >440 ms (34.2%) as compared to normal ECGs (23.0%, p<0.01 for both). In persons with CVD/tRF, a CAC-score > or =75th percentile was found in subjects with A-Fib (46.3%), borderline-LVH (39.1%), ECG signs of MI (40.5%) and major ECG abnormalities (40.3%) versus 31.2% in those with normal ECGs (p<0.03 for all). In multivariate analysis, LVH (p=0.025) and major ECG abnormalities (p=0.04) remained independently associated with CAC in subjects without and with CVD/tRF, respectively.

CONCLUSIONS: ECG-based evidence of myocardial disease is often associated with an elevated CAC burden, suggesting a link between epicardial and myocardial manifestations of risk factor exposure. The association of CAC burden with different ECG abnormalities in different clinical groups may have implications for the interpretation of the resting ECG and CAC burden in risk stratification.