Exercise Doppler echocardiography (EDE) was found to provide consistent assessment of right heart function and pulmonary circulation when conducted at expert centers, according to a study published in Cardiovascular Ultrasound.
This quality-control study aimed to evaluate resting and exercise DE variables obtained across 19 experienced echocardiography laboratories in the RIGHT Heart International NETwork (RIGHT-NET). The RIGHT-NET study was designed to define normality ranges for right heart function and pulmonary circulation hemodynamics during EDE (diagnostic value) and to examine the impact on clinical outcome of abnormal responses in patients with overt pulmonary hypertension or those at risk.
A total of 10 patients undergoing EDE (mean age, 67.2 ± 11.3 years; 8 women) were randomly selected for analysis, including healthy subjects. Interobserver agreement with the core laboratory was determined by calculating intraclass correlation coefficients (ICC).
Interobserver variability for resting and peak exercise was measured using tissue Doppler imaging for tricuspid regurgitation velocity (TRV), right ventricular outflow tract acceleration time (RVOT Act), tricuspid annular plane systolic excursion (TAPSE), tissue Doppler tricuspid lateral annular systolic velocity (S’), right ventricular fractional area change (RV FAC), left ventricular outflow tract velocity time integral (LVOT VTI), mitral inflow pulsed wave Doppler velocity (E), diastolic mitral annular velocity y (e’), and left ventricular ejection fraction (LVEF).
Interobserver accuracy for all variables ranged from 99.7% to 100% (ICC >0.90). Interobserver variability for resting and exercise variables was as follows: TRV, 3.8% and 2.4%, respectively; E, 5.7% and 8.3%, respectively; e′, 6% and 6.5%, respectively; RVOT Act, 9.7% and 12%, respectively; LVOT VTI, 7.4% and 9.6%, respectively; S′, 2.9% and 2.9%, respectively; and TAPSE, 5.3% and %, respectively. There was moderate interobserver variability for resting and peak exercise RV FAC (15% and 16%, respectively), and LVEF had low resting and peak exercise variability (7.6% and 9%, respectively).
“The present results demonstrate that a rigorously designed protocol with a strong focus on quality assurance and certification can yield very strong ICC and limited variability among the 19 participant experienced centers to a large prospective EDE study of the right heart and the pulmonary circulation,” the study authors commented.
Study limitations include the lack of validation of echocardiographic measurements against the gold standard evaluation of pulmonary circulation (pulmonary artery pressure [PAP], wedged PAP, and cardiac output) and right ventricular function (indices derived from pressure-volume loops).
“When protocols for acquisition and analysis are provided upfront and in experienced echocardiography laboratories EDE represents a reproducible tool to comprehensively assess the right heart and pulmonary circulation,” the researchers concluded. “This quality control study represents a solid bedrock for future RIGHT-NET studies, aiming to evaluate the diagnostic and prognostic role of EDE in the clinical settings of patients with cardiorespiratory diseases.”
Ferrara F, Gargani L, Contaldi C, et al. A multicentric quality-control study of exercise Doppler echocardiography of the right heart and the pulmonary circulation. The RIGHT Heart International NETwork (RIGHT-NET). Cardiovasc Ultrasound. 2021;19(1):9. doi: 10.1186/s12947-021-00238-1