Comparing characteristics and clinical and echocardiographic outcomes in low‐flow vs normal‐flow severe aortic stenosis with preserved ejection fraction in an Asian population. Issue 5 (1st April 2017)

• Record Type: Journal Article
• Authors: Ngiam, Jinghao Nicholas; Tan, Benjamin Yong‐Qiang; Sia, Ching‐Hui; Lee, Glenn K.M.; Kong, William K.F.; Chan, Yiong‐Huak; Poh, Kian‐Keong
• Is Part Of: Echocardiography. Volume 34:Issue 5(2017)
• Page Start: 638
• Page End: 648
• Publication Date: 2017-04-01
• Subjects: left ventricular ejection fraction -- low‐flow -- normal‐flow -- severe aortic stenosis; Echocardiography -- Periodicals; Echocardiography -- Periodicals; 616.1207543
• DOI: 10.1111/echo.13525
• Languages: English
• ISSNs: 0742-2822

Abstract

Abstract : Background/Objectives: In severe aortic stenosis (AS), deterioration of left ventricular ejection fraction (LVEF) to <50% is an AHA/ACC class I indication for valve replacement, regardless of symptoms. Controversy surrounds prognosis of low‐flow AS compared to normal‐flow, and no study has examined LVEF deterioration. We compared factors associated with LVEF deterioration (to <50%) and clinical outcomes. Methods: Consecutive subjects with low‐flow (stroke volume index <35 mL/m 2, n=56) and normal‐flow (n=72) severe AS (aortic valve area <1 cm 2 ) with preserved LVEF (>50%) and with paired echocardiography were studied. Univariate and multivariate analyses identified factors associated with LVEF deterioration. Clinical outcomes were determined on follow‐up for more than 5 years. Results: Significant LVEF deterioration (to <50%) was seen in 18% of low‐flow (initial LVEF 63±8% to 32±9%) and 18% of normal‐flow AS (61±7% to 31±12%). Independent factors in low‐flow AS were hypertension (OR: 30.7, 95% CI: 2.0–467.6, P =.014) and higher end‐systolic wall stress (OR: 1.086, 95% CI: 1.022–1.153, P =.008), compared to normal‐flow, which were hypertension (OR: 15.9, 95% CI: 3.1–81.9, P =.001), higher septal E/E′ ratio (OR: 1.16, 95% CI: 1.01–1.35, P =.043), lower septal S′ velocity (OR: 0.204, 95% CI: 0.061–0.682, P =.010), and higher end‐systolic wall stress (OR: 1.051, 95% CI: 1.001–1.104, P =.047). Overall, a third of the cohort experienced MACE, regardless of flow (log‐rank 0.048, P =.827). However, aortic valve replacement (AVR) rates were lower in low‐flow AS (20% vs 43%, P =.005). Conclusions: Low‐flow AS despite normal LVEF appears similar to normal‐flow in terms of LVEF deterioration and clinical outcomes in our Asian population. AVR rate was lower even though low‐flow may not reflect less severe disease.