Speckle-Tracking Echocardiography for Predicting Outcome in Chronic Aortic Regurgitation During Conservative Management and After Surgery
Is myocardial deformation imaging using speckle-tracking echocardiography useful for predicting outcomes in chronic aortic regurgitation?
A longitudinal study was performed in 64 patients with moderate to severe aortic regurgitation. Of these, 35 patients were managed conservatively with frequent clinical visits and sequential echocardiography and followed for an average of 19 ± 8 months, while 29 patients underwent surgery for the valve lesion and were followed for 6 months postoperatively. Baseline left ventricular (LV) function by speckle-tracking and conventional echocardiography was compared with impaired outcome after surgery (defined as persistent symptoms or persistent LV dilation [LV end-diastolic volume index ≥87 ml/m2] or dysfunction [LV ejection fraction <50%]), and with disease progression during conservative management (defined as development of symptoms, increase in LV volume >15%, or decrease in LV ejection fraction >10%).
Reduced myocardial systolic strain, systolic strain rate, and early diastolic strain rate by speckle-tracking echocardiography were associated with disease progression during conservative management (–16.3% vs. –19.0%, p = 0.02; –1.04 vs. –1.19 s–1, p = 0.02; and 1.20 vs. 1.60 s–1, p = 0.002, respectively) and with impaired outcome after surgery (–11.5% vs. –15.6%, p = 0.01; –0.88 vs. –1.01 s–1, p = 0.04; and 0.98 vs. 1.33 s–1, p = 0.01, respectively). Conventional parameters of LV function and size (LV ejection fraction and LV end-diastolic volume index) were associated with outcome after surgery (p = 0.04 and p = 0.01, respectively), but not with outcome during conservative management (p = 0.57 and p = 0.39, respectively).
Speckle-tracking echocardiography is useful for the early detection of LV systolic and diastolic dysfunction in chronic aortic regurgitation.
Compared to decades past, improved operative outcomes have led to recommendations for intervention relatively sooner for many heart valve lesions. Most notably, chronic severe mitral regurgitation now can be operated on prophylactically, based on a high likelihood for successful mitral repair. However, patients with severe aortic regurgitation, who face likely valve replacement, still currently face surgical intervention relatively late in the course of disease (with indications for intervention based on development of heart failure or marked LV dilation). However, many patients who undergo aortic valve replacement for aortic regurgitation within guideline recommendations nonetheless have persistent LV dilation or LV dysfunction after surgery. This study is important in that it highlights other indices (in the form of systolic and diastolic strain, and systolic strain rate) that might portend subclinical LV dysfunction, and in the future might be used to better time surgical intervention among patients with chronic LV volume overload.
Keywords: Mitral Valve Insufficiency, Heart Failure, Diastole, Ventricular Dysfunction, Left, Systole, Echocardiography
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