Does coronary calcium score predict future cardiac function? Association of subclinical atherosclerosis with left ventricular systolic and diastolic dysfunction at MR imaging in an elderly cohort.

PURPOSE

To evaluate subclinical atherosclerosis measured by using coronary artery calcium (CAC) as a predictor of future left ventricular (LV) systolic and diastolic function in asymptomatic elderly participants.

MATERIALS AND METHODS

The institutional review boards of the University of Southern California and the Harbor University of California Los Angeles Research and Education Institute (where the South Bay Heart Watch study was initially conducted) approved this HIPAA-compliant study of 386 participants (mean age, 75.2 years) from among the original 1461 participants in the longitudinal South Bay Heart Watch prospective investigation of subclinical atherosclerosis. CAC at computed tomography was correlated with LV ejection fraction (LVEF), regional wall motion abnormalities (RWMAs), and peak filling rate (PFR) assessed a mean of 11.4 years ± 0.6 (standard deviation) later with cardiac magnetic resonance imaging. Analysis of variance and covariance testing was performed with the Wald test, testing for trends across the CAC groups. Covariates included age, level of total cholesterol, level of high-density lipoprotein cholesterol, systolic blood pressure, use of lipid-lowering medication, and smoking status.

RESULTS

Mean LVEF was 60.3% ± 9.9, with 11 (2.8%) of 386 participants having an LVEF of less than 40%. Forty-six (11.9%) of 386 participants had RWMAs. Higher CAC scores were associated with slightly lower LVEF (P for trend = .04) and a greater percentage of participants with decreased PFR (P for trend = .47) and RWMAs (P for trend = .01). After age- and risk factor-adjustment, only RWMA (P = .05) was associated with higher CAC. RWMAs were associated with significantly (P < .001) lower mean LVEF and PFR. Nineteen (41%) of 46 participants with RWMAs had documented Q-wave myocardial infarction, and three (7%) underwent coronary revascularization. CAC scores of 100 or greater were associated with a 2.2-fold (95% confidence interval: 1.30, 3.75) increase in RWMA (P < .001).

CONCLUSION

Subclinical atherosclerosis assessed by using CAC is associated with an increased future likelihood of RWMA, as a marker of previous and possible subclinical coronary artery disease.