Prognostic Value of Energy Loss Index in Asymptomatic Aortic Stenosis (original) (raw)

C urrent guidelines recommend a variety of Doppler echocardiographic measures for assessing the severity of aortic stenosis (AS), including peak aortic jet velocity, mean aortic gradient, aortic valve area (AVA), and AVA indexed for body surface area (AVAI). 1-5 These measures may categorize the severity of AS differently, and inconsistently graded severe AS has been reported in up to 30% of patients. 6 In particular, AS severity is frequently overestimated by AVAI in patients with milder degree of AS if pressure recovery in the aortic root is not taken into account. 7 Recently, it was demonstrated that patients with inconsistently graded severe AS had a prognosis comparable to that seen in patients with moderate AS. 8 Whether assessment of pressure recovery adjusted AVAI (energy loss index [ELI]) in this setting could add accuracy to risk assessment is unknown. Editorial see p 1101 Clinical Perspective on p 1156 In AS, therapeutic decisions are based on symptomatic status, hemodynamic severity, and left ventricular function. 1,4 Accurate echocardiographic assessment of AS severity is of major clinical importance. It has been suggested that ELI may more accurately reflect the severity of AS. 9-11 However, the prognostic value of ELI has not been assessed in a large, prospective study. Thus, the aim of the present analysis was to determine whether ELI was superior to conventional, commonly used measures of AS severity in predicting aortic valve events (AVEs) and total mortality in initially asymptomatic AS patients. Methods Study Population The present analysis was prospectively planned within the Simvastatin and Ezetimibe in Aortic Stenosis (SEAS) study, which enrolled 1873 Background-Aortic valve area index adjusted for pressure recovery (energy loss index [ELI]) has been suggested as a more accurate measure of aortic stenosis (AS) severity, but its prognostic value has not been determined in a prospective study. Methods and Results-The relation between baseline ELI and rate of aortic valve events and combined total mortality and hospitalization for heart failure resulting from the progression of AS was assessed by multivariate Cox regression and reclassification analysis in 1563 patients with initial asymptomatic AS in the Simvastatin and Ezetimibe in Aortic Stenosis (SEAS) study. During 4.3 years follow-up, a total of 498 aortic valve events and 181 combined total mortalities and hospitalizations for heart failure caused by the progression of AS occurred. In Cox regression analyses, 1-cm 2 /m 2 lower baseline ELI predicted a 2-fold higher risk both for aortic valve events and for combined total mortality and hospitalization for heart failure independently of baseline peak aortic jet velocity or mean aortic gradient and independently of aortic root size (all P<0.05). In reclassification analysis, ELI improved the prediction of aortic valve events by 13% (95% confidence interval, 5-19), whereas the prediction of combined total mortality and hospitalization for heart failure resulting from the progression of AS did not improve significantly. Conclusions-In asymptomatic AS patients without known atherosclerotic disease or diabetes mellitus, ELI provides independent and additional prognostic information to that derived from conventional measures of AS severity, suggesting that ELI should be measured in such patients.