What is the clinical evidence from this study?

Study design: Cohort. Population: Severe symptomatic aortic stenosis (n=110). Intervention: Aortic Valve Replacement (AVR) vs. Baseline (pre-operative). Primary outcome: Atrioventricular area difference (AVAD) at mid-diastole (p=0.70).

June 20, 2025Open Access

Hydraulic forces assist left ventricular filling in aortic stenosis and improve after valve replacement in patients with the lowest hydraulic force and otherwise healthiest left ventricles at baseline

Key Result

Aortic valve replacement did not significantly change the atrioventricular area difference on a group level (2.8 vs 2.6 cm2, p=0.70), but improvements were associated with lower baseline AVAD, lower age, and less left ventricular remodeling.

Study Design

Type

Cohort (n=110)

Multicenter

Structured PICO

Population

110 patients with severe, symptomatic aortic stenosis undergoing aortic valve replacement, median age 71, 54% male, single-center (United Kingdom). Key exclusions: eGFR <30 ml/min/1.73m2, previous cardiac valve procedures, infective endocarditis, severe mitral or aortic regurgitation, cardiac amyloid.

Intervention

Aortic valve replacement (AVR), including transcatheter (5%), tissue surgical (62%), mechanical surgical (30%), and suture-less surgical (4%), with or without concomitant coronary artery bypass grafting (32%).

Outcome

Change in atrioventricular area difference (AVAD) at mid-diastole measured by cardiovascular magnetic resonance at 1-year post-operativelysurrogate

In patients with severe aortic stenosis, hydraulic forces assist left ventricular filling, and improvement after valve replacement is greatest in younger patients with less adverse myocardial remodeling, supporting early intervention.

Main Result

Absolute Event Rate: 2.6% vs 2.8%

p-value: p=0.70

Limitations

Circular approximation was used to calculate the atrial short-axis area (ASA) instead of measuring the true area.
The CMR protocol used to acquire short-axis images did not fully cover the left atria.
Atrioventricular area difference (AVAD) was only measured during mid-diastole rather than throughout the cardiac cycle.

Abstract

ABSTRACT Background Diastolic dysfunction in the setting of aortic valve replacement (AVR) for aortic stenosis (AS) is incompletely understood. This study aims to to assess the net hydraulic force of left ventricular (LV) filling in participants with severe symptomatic AS undergoing AVR. Methods This single-centre prospective observational cohort study evaluated patients with severe, symptomatic AS undergoing AVR between 2012-2015. Clinical assessment and cardiovascular magnetic resonance (CMR) was completed prior to AVR and 1-year post-operatively. Atrioventricular area difference (AVAD) was used as a surrogate for the hydraulic force of LV filling. AVAD at mid-diastole was measured as the difference between LV short-axis area and left atrial short-axis area. Results In patients with AS (n=110, 54% male, age 71 64–77 years, aortic valve area 0.74±0.25 cm 2 ), AVAD was positive at baseline (2.8±6.5 cm 2 ) consistent with a net hydraulic force assisting LV filling. While AVAD did not change post-operatively on a group level (p=0.70), an improvement in AVAD was associated univariably with increasing baseline LV ejection fraction, and decreasing baseline AVAD, LV volume, mass, myocardial extracellular volume, and infarct size (p<0.05 for all), and multivariably with baseline decreasing AVAD, LV mass, and age (model adjusted R 2 =0.49, p<0.001). Conclusion In severe AS, hydraulic force contributes to LV filling prior to and following AVR. The greatest improvement in hydraulic force following AVR occurred in those with the lowest baseline hydraulic force, but also with lower age and the absence of otherwise deleterious LV myocardial remodelling, thus supporting the benefits of early intervention.

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