Combined coronary and mitral annulus calcium detection in the non-invasive diagnosis of coronary artery disease in patients with systemic hypertension

BACKGROUND: Although the presence of coronary calcium (CC) on fast spiral computed tomography (FSCT) is a powerful predictor of coronary artery disease (CAD), both the specificity and positive predictive value (PPV) of CC in CAD diagnosis are modest. Since previous studies have shown an association between mitral annular calcification (MAC) and coronary atherosclerosis, we aimed to investigate whether combined coronary and MAC detection could improve the non-invasive diagnosis of CAD. DESIGN AND METHODS: Our study comprised 522 patients (284 men and 238 women, age ranged from 52-80 years, mean 65 +/- 6 years) who underwent FSCT of the coronaries as well as echo-Doppler examination. Among them, 97 patients had prior diagnosis of prevalent proven CAD (CAD group) while 425 patients were without clinically manifested CAD (the No CAD group). RESULTS: The prevalence of CC in the CAD group was 95 versus 68% in the No CAD group (P = 0.001). The prevalence of MAC in CAD group was 63 versus 51% in No CAD group (P = 0.03). Sensitivity and negative predictive value (NPV) of CC as a predictor of CAD were 95 and 96% respectively, but specificity and PPV were low: 32 and 24% respectively. Sensitivity and NPV of MAC as predictors of CAD were 63 and 85% respectively; specificity and PPV, 49 and 22% respectively. Using of combined CC and MAC evaluation in the prediction led to some specificity improvement at the expense of a similar sensitivity reduction, without a considerable gain in the total accuracy of the method. CONCLUSIONS: Coronary calcium detection on FSCT in hypertensive patients yields excellent sensitivity and NPV but relatively low specificity and PPV for clinically manifested CAD. Mitral annular calcification assessment yields a low sensitivity and specificity and its addition to CC evaluation does not improve non-invasive diagnosis of CAD.