Severe aortic valve stenosis with low-gradient and preserved ejection fraction: a misclassification issue?

Area of Science:

• Cardiology
• Echocardiography
• Valvular Heart Disease

Background:

• Low-gradient severe aortic stenosis with preserved ejection fraction presents diagnostic challenges.
• Misclassification of aortic stenosis severity can impact patient prognosis.
• Three-dimensional transesophageal echocardiography (3D-TEE) offers potential for accurate aortic valve area assessment.

Purpose of the Study:

• To evaluate the agreement between transthoracic echocardiography (TTE) and 3D-TEE for measuring aortic valve area (AVA) in patients with low-gradient severe aortic stenosis.
• To determine the prevalence of paradoxical low-gradient severe aortic stenosis using 3D-TEE planimetry.

Main Methods:

• A cross-sectional study included patients with severe aortic stenosis undergoing both TTE and 3D-TEE.
• Paradoxical low-gradient severe aortic stenosis was defined by AVA <1 cm², mean gradient <40 mmHg, and ejection fraction ≥50% on TTE.
• Concordance between AVA measurements from TTE (continuity equation) and 3D-TEE (planimetry) was assessed.

Main Results:

• Of 212 patients with severe aortic stenosis, 63 (29.7%) met criteria for paradoxical low-gradient severe aortic stenosis.
• 3D-TEE planimetry was successful in 61 patients (96.8%).
• 85.2% of these patients had an AVA <1 cm² by 3D-TEE, confirming the entity. The intraclass correlation coefficient between TTE and 3D-TEE was 0.505 (P<.001).

Conclusions:

• Paradoxical low-gradient severe aortic stenosis is a validated clinical entity.
• 3D-TEE planimetry confirms the diagnosis in a high percentage of these patients.
• 3D-TEE provides a more precise measurement of aortic valve area in this specific patient group.