Overview :

Aortic stenosis (AS) is the most frequent valvular heart disease and the most frequent cause of valve procedure. There is currently no pharmacological therapy available to reduce the progression of AS and aortic valve replacement (AVR) is thus the only available treatment for this disease. During the past decade, Transcatheter Aortic Valve Replacement (TAVR) has emerged as an alternative to Surgical Aortic Valve Replacement (SAVR).

The therapeutic management of AS is essentially determined by:

1. The severity of the stenosis
2. The patient’s symptomatic status
3. The status of LV systolic function

What is SEVERE AS and LOW GRADIENT AS

Severe AS is defined as a peak aortic jet velocity ≥ 4 m/s, a mean transvalvular pressure gradient ≥ 40 mmHg, and/or an aortic valve area (AVA) < 1.0 cm². An important proportion of patients with AS have a ‘low-gradient’ AS, i.e. a small AVA (<1.0 cm²) consistent with severe AS but a low-gradient (<40 mmHg) consistent with non-severe AS. The management of this subset of patients is particularly challenging because the AVA-gradient discrepancy raises uncertainty about the actual stenosis severity and thus about the indication of AVR if the patient has symptoms or LVEF < 50%.

CAUSE OF LOW GRADIENT AS:

The most frequent cause of low-gradient (LG) AS is the presence of a low LV outflow state, which may occur with reduced LVEF, i.e. classical low flow, or preserved LVEF, i.e. paradoxical low flow. The transvalvular pressure gradient is highly flow-dependent (i.e. a squared function of flow) and may thus be ‘pseudo-normalized’ and underestimate stenosis severity in presence of low flow. The purpose of this article is to provide a state-of-the art review of the clinical management for these three subtypes of LG AS.

DIAGNOSIS:

One of the main diagnostic challenges in LF-LG AS is to differentiate a true-severe AS that generally benefits from AVR vs. a pseudo-severe AS (i.e. non-severe AS with incomplete valve opening) that may not benefit from this intervention. A low-dose dobutamine stress echocardiography (DSE) is recommended to confirm stenosis severity and assess LV flow reserve

If Untreated:

If left untreated, severe aortic stenosis can lead to heart failure, Intense fatigue, shortness of breath, and swelling of your ankles and feet are all signs of this. It can also lead to heart rhythm problems (arrhythmias) and even sudden cardiac death.