Moderate Aortic Stenosis and Reduced Left Ventricular Ejection Fraction: Current Evidence and Challenges Ahead

Area of Science:

• Cardiology
• Cardiovascular Imaging
• Interventional Cardiology

Background:

• Moderate aortic stenosis (AS) with reduced left ventricular ejection fraction (LVEF < 50%) is a distinct clinical entity.
• Prevalence is estimated at 0.8% in patients undergoing echocardiography, with younger demographics and higher rates of prior myocardial infarction compared to severe AS.
• These patients exhibit significant one-year mortality, particularly those managed with medical therapy alone.

Purpose of the Study:

• To review the clinical entity of moderate AS with reduced LVEF.
• To discuss diagnostic challenges and propose nomenclature revisions.
• To highlight the need for standardized clinical pathways and complementary diagnostic tools.

Main Methods:

• Review of retrospective data and existing literature on moderate AS and reduced LVEF.
• Discussion of diagnostic criteria and challenges in echocardiography.
• Exploration of complementary imaging modalities like dobutamine stress echocardiography and CT.
• Reference to the ongoing TAVR UNLOAD trial (NCT02661451).

Main Results:

• Moderate AS with reduced LVEF is associated with substantial one-year mortality (9-32% in retrospective studies).
• Current echocardiographic guidelines primarily focus on severe AS, neglecting moderate and mild AS presentations.
• Dobutamine stress echocardiography and CT show promise as complementary diagnostic tools.

Conclusions:

• A revised nomenclature and standardized diagnostic pathway are needed for moderate AS with reduced LVEF.
• Early identification and referral to heart valve centers are crucial.
• Transcatheter aortic valve replacement (TAVR) is being investigated as a potential therapy in the TAVR UNLOAD trial.