Prognostic value of stress echocardiography assessed by the ABCDE protocol

Aim: The aim of this study was to assess the prognostic value of ABCDE-SE in a prospective, large scale, multicentre, international, effectiveness study. Stress echocardiography (SE) was recently upgraded to the ABCDE protocol: step A, regional wall motion abnormalities; step B, B lines; step C, left ventricular contractile reserve; step D, Doppler-based coronary flow velocity reserve in left anterior descending coronary artery; and step E, electrocardiogram-based heart rate reserve. Methods and results: From July 2016 to November 2020, we enrolled 3574 all-comers (age 65 ± 11 years, 2070 males, 58%; ejection fraction 60 ± 10%) with known or suspected chronic coronary syndromes referred from 13 certified laboratories. All patients underwent clinically indicated ABCDE-SE. The employed stress modality was exercise (n = 952, with semi-supine bike, n = 887, or treadmill, n = 65 with adenosine for step D) or pharmacological stress (n = 2622, with vasodilator, n = 2151; or dobutamine, n = 471). SE response ranged from score 0 (all steps normal) to score 5 (all steps abnormal). All-cause death was the only endpoint. Rate of abnormal results was 16% for A, 30% for B, 36% for C, 28% for D, and 37% for E steps. During a median follow-up of 21 months (interquartile range: 13-36), 73 deaths occurred. Global X2 was 49.5 considering clinical variables, 50.7 after step A only (P = NS (not significant)) and 80.6 after B-E steps (P < 0.001 vs. step A). Annual mortality rate ranged from 0.4% person-year for score 0 up to 2.7% person-year for score 5. Conclusion: ABCDE-SE allows an effective prediction of survival in patients with chronic coronary syndromes.