Inaccuracy of dipyridamole echocardiography or scintigraphy for the diagnosis of coronary artery disease in patients with both left bundle branch block and left ventricular dysfunction

Non-invasive diagnosis of coronary artery disease (CAD) in patients with left ventricular (LV) dysfunction and left bundle branch block (LBBB) remains challenging, and there is no consensus on the role of myocardial sesta-MIBI perfusion scintigraphy with pharmacological stress (dip-MIBI) or dipiridamole echocardiography (dip-ECHO). We thus performed a prospective study to test the diagnostic accuracy of such non-invasive tests. 27 consecutive patients with both LV dysfunction and LBBB undergoing diagnostic work-up for CAD were studied simultaneously with dip-ECHO and dip-MIBI. The sensitivity for CAD for dip-ECHO and dip-MIBI was respectively 42% and 67%, with specificity 93% and 53%, and likelihood ratio (LR)-positive 6.3 and LR-negative 0.6 for both. Given the low accuracy of both dip-ECHO and dip-MIBI in detecting CAD in patients with concomitant LV dysfunction and LBBB, coronary angiography should be performed as the default diagnostic strategy in such patients.