ABCDEG Stress Echocardiography in Aortic Stenosis

Abstract

Rest and stress echocardiography (SE) plays a pivotal role in the evaluation of valvular heart disease. The use of SE is recommended in valvular heart disease when there is a mismatch between resting transthoracic echocardiography findings and symptoms. In aortic stenosis (AS), rest echocardiographic analysis is a stepwise approach that begins with the evaluation of aortic valve morphology and proceeds to the measurement of the transvalvular aortic gradient and aortic valve area (AVA) using continuity equations or planimetry. The presence of the following three criteria suggests severe AS: AVA < 1.0 cm2, a peak velocity > 4.0 m/s, or a mean gradient > 40 mmHg. However, in approximately one in three cases, we can observe a discordant AVA < 1 cm2 with a peak velocity < 4.0 m/s or a mean gradient <40 mmHg. This is due to reduced transvalvular flow associated with LV systolic dysfunction (LVEF < 50%) defined as “classical” low-flow low-gradient (LFLG) AS or normal LVEF “paradoxical” LFLG AS. SE has an established role in evaluating LV contractile reserve (CR) patients with reduced LVEF. In classical LFLG AS, LV CR distinguished pseudo-severe AS from truly severe AS. Some observational data suggest that long-term prognosis in asymptomatic severe AS may not be as favorable as previously thought, offering a window of opportunity for intervention prior to the onset of symptoms. Therefore, guidelines recommend evaluating asymptomatic AS with exercise stress in physically active patients, particularly those younger than 70 years, and symptomatic classical LFLG severe AS with low-dose dobutamine SE. A comprehensive SE assessment includes evaluating valve function (gradients), the global systolic function of the LV, and pulmonary congestion. This assessment integrates considerations of blood pressure response, chronotropic reserve, and symptoms. StressEcho 2030 is a prospective, large-scale study that employs a comprehensive protocol (ABCDEG) to analyze the clinical and echocardiographic phenotypes of AS, capturing various vulnerability sources which support stress echo-driven treatment strategies.

Impact of Stress Echocardiography on Aortic Valve Stenosis Management

“…In valvular heart disease, it has been proposed that ABCDE SE may be integrated and enriched to assess transvalvular gradients (step G). This step includes evaluation of the Vmax, trans-aortic maximal, and mean gradients using continuous-wave Doppler techniques, evaluation of integral flow in the LVOT using pulsed-wave Doppler methods, and calculation of the stroke volume and AVA using the continuity equation method [ 7 ]. Each step is important in forming the outcome and represents a potential therapeutic target, inducing personalised risk stratification and tailored therapy approaches [ 6 ].…”

Exercise Pulmonary Hypertension in Heart Valve Disease

“…The previous version of the 2017 ESC Guidelines [ 21 ] mentioned sPAP 60 mmHg at rest (confirmed with invasive measurement), as one of the findings in favor of aortic valve replacement (AVR) in asymptomatic severe AS with normal LVEF (class IIa). Furthermore, given that pulmonary congestion continues to be present after stress testing, the evaluation of pulmonary B-lines during the recovery stage of ESE can add further prognostic information, as stated in the comprehensive ABCDEG stress-echo approach [ 38 ].…”