Severe coronary artery calcifications are associated with ischemia in patients undergoing medical therapy

Background The role of coronary artery calcification (CAC) detection in individuals undergoing medical therapy is controversial. These patients frequently exhibit an artificially low clinical suspicion for obstructive heart disease. Whether detection of CAC adds value to their assessment is unknown. Methods and Results We conducted a cross-sectional analysis of 703 adequately treated individuals who had CAC scoring with electron beam computed tomography and myocardial perfusion imaging within 6 months. We assessed the association of risk factor analysis and CAC scoring with myocardial perfusion imaging abnormalities. Univariate associations between ischemia and male gender, low high-density lipoprotein, high body mass index, diabetes, and CAC score were noted. Despite reasonable control of blood pressure and low-density lipoprotein, the prevalence of inducible ischemia was 0.8%, 4.8%, 5.7%, 8.0%, and 15.1% across CAC scores of 0 to 10, 11 to 100, 101 to 400, 401 to 1000, and greater than 1000, respectively ( P <.001 for trend). Logistic regression analysis demonstrated that, after adjustment for risk factors the odds of ischemia was 3.0 (95% confidence interval, 1.5–5.7) in individuals with CAC scores greater than 400 compared with those with CAC scores of 400 or less. Conclusions The presence of a CAC score greater than 400 is associated with ischemia in a population receiving good medical therapy. The detection of significant CAC in these individuals warrants additional evaluation for ischemia.