The aim – to elaborate and to validate the combined non-invasive method to reveal the obstructive сoronary artery disease (CAD) presence using its clinical pretest probability value in conjunction with tissue Doppler data of local systolic wall motion.
Material and methods. 81 pts with typical anginal and atypical chest pain and known absence of structural myocardial diseases as well as history of myocardial infarction and coronary revascularization, 64 % men, age 56.2±9.9 yrs old were examined. All patients were divided into investigational (teaching) and checking group (49 and 32 patients, accordingly) comparable by age, gender and main comorbidities rates. The index of coronary obstruction (INCO) was expressed in conventional units and was calculated as the ratio of CAD pretest probability to mean systolic wall motion velocity of 12 myocardial segments by tissue Doppler imaging.
Results. Invasive angiography identified obstructive lesions of coronary arteries in 37 patients, including 23 patients (47 %) of the investigational group and 14 (44 %) in checking group. The investigational group patients’ INCO composed 7.8±3.8 conv units with bimodal distribution of the parameter and cut-off point at 8 conv units which corresponds to 80 % sensitivity and 91 % specificity, AUC in ROC analysis 0,965. Comparable diagnostic properties of INCO at 8 conv units were confirmed during the further analysis in checking group with 85 % sensitivity and 95 % specificity, AUC 0.971.
Conclusions. New complex non-invasive diagnostic method including INCO calculation based on CAD pretest probability and local systolic wall motion velocities evaluation by tissue Doppler was proposed. High INCO sensitivity and specificity at value – 8 conv units to determine obstructive lesions in coronary arteries were shown. INCO calculation may be widely used at the first step of non-invasive diagnosis in suspected CAD, as well as for determination of the further strategy in patients after coronary revascularization.