Refinements in stress echocardiographic techniques improve inter-institutional agreement in interpretation of dobutamine stress echocardiograms

Aims To determine the degree of inter-institutional agreement in the assessment of dobutamine stress echocardiograms using modern stress echocardiographic technology in combination with standardized data acquisition and assessment criteria. Method and Results Among six experienced institutions, 150 dobutamine stress echocardiograms (dobutamine up to 40μg.kg−1 min−1 and atropine up to 1mg) were performed on patients with suspected coronary artery disease using fundamental and harmonic imaging following a consistent digital acquisition protocol. Each dobutamine stress echocardiogram was assessed at every institution regarding endocardial visibility and left ventricular wall motion without knowledge of any other data using standardized reading criteria. No patients were excluded due to poor image quality or inadequate stress level. Coronary angiography was performed within 4 weeks. Coronary angiography demonstrated significant coronary artery disease (≥50% diameter stenosis) in 87 patients. Using harmonic imaging an average of 5·2±0·9 institutions agreed on dobutamine stress echocardiogram results as being normal or abnormal (mean kappa 0·55; 95% CI 0·50–0·60). Agreement was higher in patients with no (equal assessment of dobutamine stress echocardiogram results by 5·5±0·8 institutions) or three-vessel coronary artery disease (5·4± 0·8 institutions) and lower in one- or two- vessel disease (5·0±0·9 and 5·2±1·0 institutions, respectively; P =0·041). Disagreement on test results was greater in only minor wall motion abnormalities. Agreement on dobutamine stress echocardiogram results was lower using fundamental imaging (mean kappa 0·49; 95% CI 0·44–0·54; P <0·01 vs harmonic imaging). Conclusion Modern echocardiographic technology in combination with standardized digital image processing and uniform reading criteria results in a higher inter-institutional agreement in the interpretation of dobutamine stress echocardiogram compared to historic reports.