Exercise echocardiography predicts development of left ventricular dysfunction in medically and surgically treated patients with asymptomatic severe aortic regurgitation

Abstract

Objective-To assess resting and exercise echocardiography for prediction of left ventricular dysfunction in patients with significant asymptomatic aortic regurgitation. Design-Cohort study of patients with aortic regurgitation. Setting-Tertiary referral centre specialising in valvar surgery. Patients-61 patients (38 men, 23 women; mean (SD) age 53 (14) years) with asymptomatic or minimally symptomatic aortic regurgitation and no known coronary artery disease; 35 were treated medically and 26 had aortic valve replacement. Interventions-Exercise echocardiography was used to evaluate ejection fraction, which was measured on the resting and post-stress images using the modified Simpson method. Patients with an increment of ejection fraction after exercise were denoted as having contractile reserve (CR+); those without an increment were labelled CR−. Main outcome measures-Standard univariate and multivariate methods and receiver operating characteristic analyses were used to assess the ability of contractile reserve to predict follow up ejection fraction. Results-In the 35 medically treated patients, 13 of 21 (62%) with CR+ (mean (SD) ejection fraction increment 7 (3)%) had preserved ejection fraction on follow up. In the 14 patients with CR− (ejection fraction decrement 8 (4)%), 13 (93%) had a decrement of ejection fraction on follow up from 60 (5)% at baseline to 54 (3)% on follow up (p = 0.005). Age, resting left ventricular dimensions, medical treatment, aortic regurgitation severity, exercise capacity, and rate-pressure product were similar in both CR+ and CR− groups. Among the 26 surgical patients, 13 showed CR+ (ejection fraction increase 9 (5)%), all of whom had an increase in ejection fraction on follow up (from 49% to 59%). Of 13 surgical patients with CR− (ejection fraction decrease 7 (5)%), 10 (77%) showed the same or worse ejection fraction on postoperative follow up. Conclusions-Contractile reserve on exercise echocardiography is a better predictor of left ventricular decompensation than resting indices in asymptomatic patients with aortic regurgitation. In patients undergoing aortic valve replacement, contractile reserve had a better correlation with resting ejection fraction on postoperative follow up. Measurement of contractile reserve may be useful to monitor the early development of myocardial dysfunction in asymptomatic patients with aortic regurgitation, and may help to optimise the timing of surgery. (Heart 2000;84:606-614)

Contractile Reserve Determined on Exercise Echocardiography in Patients With Severe Aortic Regurgitation

“…This appears to be valid in patients undergoing AVR and in those on medical treatment. 9 The added usefulness of CR in determining the timing of AVR, and the relationship of CR to other baseline characteristics have not been fully defined. Hence, we performed resting and exercise echocardiography to assess CR in asymptomatic or mildly symptomatic patients with severe AR and to determine potential clinical applications of CR.…”

“…9,15,17,18 Also, CR may be useful in monitoring the early development of myocardial dysfunction in asymptomatic patients with AR. 9 To evaluate the presence of CR in AR, exercise stress echocardiography should be performed. A previous study found no correlation between LVEF response to exercise and resting LV dimensions or LVEF in a group of patients with AR compared to normal controls.…”

“…4 A previous study showed that preoperative exercise echocardiography is a better predictor of postoperative LV function than resting indices in patients with AR. 9 It is of the utmost importance that patients with AR be operated on in time to prevent the development of irreversible LV dysfunction. Conventional echocardiography at rest may be insufficient for the early detection of LV dys-Contractile Reserve in AR nal views according to standard guidelines.…”

“…9 Patients with EF augmentation with exercise were designated as having CR (+), and those failing to augment were identified as CR (−).…”

The Emerging Role of Exercise Testing and Stress Echocardiography in Valvular Heart Disease

“…The observed magnitude of change in ejection fraction or stroke volume from rest to exercise is related not only to myocardial contractile function but also to severity of volume-overload and exercise-induced changes in pre-load and peripheral resistance (1). The validity of stress echocardiography in predicting outcome of patients with asymptomatic AR is limited by the small number of available studies (39,40) compared with the more extensive and consistent experience with exercise radionuclide angiography (41)(42)(43)(44). With the sparse data supporting the incremental prognostic value of stress echocardiography, this specific application is not recommended for routine clinical use (1).…”