Progression of moderate to severe aortic stenosis: new insights into cardiac remodeling

Abstract

moderate AS and first diagnosis of progression to severe AS. LV global longitudinal strain (GLS) was evaluated using automated function imaging (GE Medical systems, Horten, Norway). LV diastolic function was assessed according to current guidelines and patients were divided into 3 groups (normal diastolic function, indeterminate diastolic function or diastolic dysfunction)[4]. Patients were also categorized into different LV remodeling patterns, defined by relative wall thickness and LV mass index: normal geometry, concentric remodeling, concentric hypertrophy or eccentric hypertrophy [5]. General linear models with repeated measures analysis were used to evaluate changes in echocardio-graphic variables over time. A total of 470 patients (mean age 69 ± 12 years, 61% male) were identified. There was a high proportion of patients with cardiovascular comorbidities (dyslipidaemia 61%, diabetes mellitus 24%, smoking 13%, atrial fibrillation 24%). At the diagnosis of moderate AS, AVA was 1.24 ± 0.14 cm 2 , MG 25 ± 9 mmHg and peak gradient 40 ± 13 mmHg. Mean LV ejection fraction was 58 ± 11%, LV GLS 15.7 ± 3.6% and LV mass index 112 ± 32 g/m 2. Concentric hypertrophy (34%) was the most frequently observed LV remodeling pattern followed by concentric remodeling (29%), eccentric hypertrophy (19%) and normal geometry (18%) (Fig. 1A). At the time of the first echocardiogram, 39% of the study population had normal LV diastolic function, 26% indeterminate LV diastolic function and 35% LV diastolic dys-function (Fig. 1B).The median time for progression from moderate to severe AS was 26 (13-43) months. At the time of first diagnosis of severe AS, AVA was 0.92 ± 0.40 cm 2 , MG 39 ± 14 mmHg and peak gradient 62 ± 21 mmHg. LV ejection fraction decreased from 58 ± 11% to 51 ± 14% (p < 0.001) and LV GLS from 15.7 ± 3.6% to 14.0 ± 4.6% (p < 0.001). LV mass index increased from 112 ± 32 g/m 2 to 130 ± 51 g/m 2 (p < 0.001). The percentage of patients with Guidelines for the management of valvular heart disease recommend aortic valve replacement in patients with severe aortic stenosis (AS) who become symptomatic or develop left ventricular (LV) systolic dysfunction (LV ejection fraction < 50%) [1]. As such, guidelines underline the prognostic role of LV performance to risk stratify patients with severe AS. Recent data demonstrated reduced long-term survival in patients with moderate AS [2]. The impact of progression from moderate to severe AS on LV performance however, is currently unknown. We aimed to investigate the effect of moderate AS progression on LV systolic function, LV dia-stolic function and LV hypertrophy by comparing the first echocardiogram on which moderate AS was diagnosed with the first echocardiogram on which severe AS was diagnosed. The study included patients ≥ 18 years who presented between October 2001 and December 2019 with a first diagnosis of moderate AS (aortic valve area (AVA) 1.0-1.5 cm 2) and who subsequently progressed to severe AS. Severe AS was defined as an AVA ≤ 1.0 cm 2 , peak aortic jet velocity ≥ 4 m/s or mean gradient (MG) ≥ 40 mmHg[3].