ANALYSIS OF INTERINSTITUTIONAL OBSERVER AGREEMENT IN INTERPRETATION OF DOBUTAMINE STRESS ECHOCARDIOGRAMS

Objectives. This study sought to determine the degree of interinstitut ional agreement in the interpretation of dobutamine stress echocardiog rams. Background. Dobutamine stress echocardiography involves subjecti ve interpretation. Consistent methods for acquisition and interpretati on are of critical importance for obtaining high interobserver agreeme nt and for facilitating communication of test results. Methods. Five e xperienced centers were each asked to submit 30 dobutamine stress echo cardiograms (dobutamine up to 40 mu g/kg body weight per min and atrop ine up to 1 mg) obtained in patients undergoing coronary angiography. Thus, a total of 150 dobutamine stress echocardiograms were interprete d by each center without knowledge of any other patient data. Left ven tricular wall motion was assessed using a 16-segment model but was oth erwise not standardized. No patient was excluded because of poor image quality or inadequate stress level. Echocardiographic image quality w as assessed using a five point scale. Results. Angiographically signif icant coronary artery disease (greater than or equal to 50% diameter s tenosis) was present in 95 patients (63%). By a majority decision (thr ee or more centers), the sensitivity, specificity and accuracy of dobu tamine echocardiography were 76%, 87% and 80%, respectively, Abnormal or normal results of stress echocardiography were agreed on by four or all five of the centers in 73% of patients (mean kappa value 0.37, fa ir agreement only), Agreement on the left anterior descending artery t erritory (78%) was similar to that for the combined right coronary art ery/left circumflex artery territory (74%), and for specific segments the agreement ranged from 84% to 97% and was highest for the basal ant erior segment and lowest for the basal inferior segment, Agreement was higher in patients with no (82%) or three-vessel coronary artery dise ase (100%) and lower in patients with one- or two vessel disease (61% and 68%, respectively). Agreement on positivity or negativity of stres s test results was 100% for patients with the highest image quality bu t only 43% for those with the lowest image quality (p = 0.003). Conclu sions. The current heterogeneity in data acquisition and assessment cr iteria among different centers results in low inter institutional agre ement in interpretation of stress echocardiograms. Agreement is higher in patients with no or advanced coronary artery disease and substanti ally lower in those with limited echocardiographic image quality. To i ncrease interinstitutional agreement, better standardization of image acquisition and reading criteria of stress echocardiography is recomme nded.