Comprehensive Echocardiographic Assessment in Moderate Aortic Stenosis with Preserved Ejection Fraction Using...

Area of Science:

• Cardiology
• Cardiovascular Imaging
• Exercise Physiology

Background:

• Moderate aortic stenosis (AS) with preserved ejection fraction (EF) presents a challenge for risk stratification.
• Cardiopulmonary exercise testing (CPET) and myocardial mechanics analysis offer potential for identifying subclinical dysfunction.

Purpose of the Study:

• To investigate the relationship between functional capacity (% predicted peak VO2), ventilatory efficiency (VE/VCO2 slope), and myocardial mechanics/work indices in moderate AS with preserved EF.

Main Methods:

• Prospective enrollment of 107 patients with moderate AS (AVA 1.0-1.5 cm2; mean gradient 20-40 mmHg; EF ≥ 50%).
• Assessment of functional capacity and ventilatory efficiency via CPET.
• Evaluation of left ventricular (LV), left atrial (LA), and right ventricular (RV) strain, and myocardial work indices using speckle tracking echocardiography (STE).

Main Results:

• Reduced % predicted VO2 was associated with higher LV end-systolic volume and lower stroke volume index.
• Poor ventilatory efficiency (VE/VCO2 slope ≥ 30) correlated significantly with impaired global longitudinal strain (GLS), LA strain (PALS, LA Scd), RV free wall strain (RW FWS), and myocardial work indices.
• LA conduit strain (LA Scd) was the strongest predictor of poor ventilatory efficiency (AUC 0.723).

Conclusions:

• Impaired ventilatory efficiency, more than reduced % predicted VO2, is linked to subclinical LV, LA, and RV dysfunction in moderate AS with preserved EF, emphasizing RV impairment.
• Integrating CPET and STE enhances patient phenotyping, aiding in the identification of high-risk individuals for closer monitoring or early intervention.