Stress echocardiography: application of the ABCDE protocol in patients with permanent atrial fibrillation

Abstract

Abstract Objectives A new standard of practice in stress echocardiography (SE) was founded with the development of the ABCDE protocol, which added functional information to conventional ischemia diagnosis. Each step showed to provide incremental prognostic information: 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 the left anterior descending coronary artery; and step E, electrocardiogram-based heart rate reserve. However, the utility of SE and ABCDE protocol in patients with atrial fibrillation (AF) has never been tested. Background A growing body of evidence suggests that AF patients have a significant residual risk of myocardial infarction despite anticoagulant treatment; furthermore, they have an increased risk of heart failure and all-cause death. However, ABCDE-SE has never been applied in this population. Methods Of the 3965 patients who completed clinically indicated ABCDE-SE and with available information on rhythm stored in the shared data bank and enrolled from 13 certified centers, 3891 were in sinus rhythm (SR, Group 1) and 50 in permanent AF (Group 2) at the time of the test. ABCDE-SE response ranged from score 0 (all steps normal) to score 5 (all steps abnormal). The employed stress was an exercise in 1626 (41%), vasodilator in 1864 (47%), and dobutamine in 475 (12%). Results Group 2 pts were older than Group 1 patients, more frequently hypertensives and diabetics, with lower ejection fraction, and with more signs of pulmonary congestion at rest. During stress, differences were magnified, and Group 2 patients showed more peak stress B-lines and higher values of peak WMSI compared with Group 1 (see Table). In addition, patients with AF had higher ABCDE scores (Group 1= 1.5 ±1.4 vs. Group 2= 2.6±1.6, p<0.0001). The distribution of the score in patients in SR and AF is shown in Figure. Conclusions Patients with AF are scarcely represented among patients undergoing SE. Patients with AF showed a higher prevalence of positivity in each step and a higher ABCDE score. More specifically, AF patients are more vulnerable than patients in SR to coronary microvascular dysfunction and chronotropic incompetence during stress.TableFigure