Is Any ABCDE Stress Echocardiography Score Equivalent to Stress-Induced Ischaemia? Reply With a Modified 2-Stage Approach

Stress echocardiography has evolved from the sole assessment of regional wall motion abnormalities (RWMAs) to the ABCDE protocol, as recommended by the recent clinical consensus statement from the European Association of Cardiovascular Imaging, reflecting the need for a more systematic patient assessment. Steps A, B, C, D, and E assess RWMAs, lung B-lines, left ventricular contractile reserve, coronary flow velocity reserve (CFVR) in mid-distal left anterior descending artery, and heart rate reserve, respectively. Impairment of CFVR is considered as the earliest abnormality in the ischaemic cascade. While mostly steps A and D have been studied for their relation to obstructive and non-obstructive coronary artery disease, the diagnostic accuracy of steps B, C, and E for chronic coronary syndromes (CCSs) remains unknown, particularly in the context of negative steps A and D. Additionally, while ABCDE steps have been studied for their prognostic significance, there is no evidence of patients management based on this protocol in order to change the estimated risk. These concepts could be depicted in a 2-stage approach. A negative stage 1 (no stress-induced RWMAs as assessed in step A and normal CFVR as assessed in step D) imply good prognosis and non-coronary causes of symptoms should be considered, whereas guidelines for CCSs should be followed in a positive stage 1. Stage 2 includes steps B, C, and E, for further risk stratification or symptoms assessment, but it lacks evidence-based risk-modifying management and is mainly useful when stage 1 is negative and a cardiac origin of symptoms is still suspected.