Classification of Aortic Stenosis by Flow and Gradient Patterns Provides Insights into the Pathophysiology of Disease. (August 2016)

• Record Type: Journal Article
• Authors: Bhattacharyya, Sanjeev; Mittal, Tarun; Abayalingam, Mayavan; Kabir, Tito; Dalby, Miles; Cleland, John G.; Baltabaeva, Aigul; Rahman Haley, Shelley
• Is Part Of: Angiology. Volume 67:Number 7(2016)
• Page Start: 664
• Page End: 669
• Publication Date: 2016-08
• Subjects: aortic stenosis -- valve calcification -- echocardiography -- cardiac computed tomography; Blood-vessels -- Diseases -- Periodicals; Cardiovascular system -- Diseases -- Periodicals; 616.13005
• DOI: 10.1177/0003319715611804
• Languages: English
• ISSNs: 0003-3197

Abstract

Different patterns of flow and valve gradients can lead to diagnostic uncertainty about the severity of aortic stenosis (AS). Consecutive patients with severe AS (valve area <1 cm 2 ) underwent echocardiography and computed tomography. Patients were classified into 4 groups (high-gradient/normal flow [HGNF ], high-gradient/low flow [HGLF ], low-gradient/normal flow [LGNF ], and low-gradient/low flow [LGLF ]). Low flow was defined as stroke volume index <35 mL/m 2 and low gradient as a mean aortic gradient <40 mm Hg. Aortic valve calcification (AVC) was calculated using the Agatston score. Of 181 patients, 56, 30, 46, and 49 had HGNF, HGLF, LGNF and LGLF with median AVC of 2048, 2015, 1366, and 1178 AU/m 2 ( P < .0001) and valvuloarterial impedance of 4.5, 6.4, 4.2, and 5.9, respectively ( P < .0001). Among those with LGLF, AVC was lower in patients with preserved compared to reduced left ventricular ejection fraction (1018 vs 2550 AU/m 2 ; P < .0001), but valvuloarterial impedance was similar ( P = .33). The LGLF AS with preserved ejection fraction is associated with lower AVC and may identify patients with less severe AS in association with an adaptive ventricular response to high afterload.