Four-dimensional flow provides incremental diagnostic value over echocardiography in aortic stenosis

Area of Science:

• Cardiovascular Imaging
• Medical Diagnostics
• Radiology

Background:

• Aortic stenosis (AS) assessment is crucial for patient management.
• Four-dimensional flow cardiovascular MRI (4D flow CMR) is an emerging technique for evaluating AS.
• Transthoracic echocardiography (TTE) is the current standard for AS assessment.

Purpose of the Study:

• To evaluate the agreement between 4D flow CMR and TTE in estimating peak aortic valve (AV) velocities (V_Peak).
• To compare AS severity grading using both modalities.
• To assess the predictive value of each technique for AV intervention.

Main Methods:

• Retrospective analysis of patients from the PREFER-CMR registry with consecutive TTE and 4D flow CMR.
• AS severity graded using established protocols with echocardiographic parameters (V_Peak, AV area, mean pressure gradient) and CMR-derived V_Peak.
• Cox-regression analysis to predict AV intervention.

Main Results:

• 30 patients (mean age 75.4 years, 67% male) included; 17 underwent AV intervention.
• 4D flow CMR-derived V_Peak was significantly higher than CWD V_Peak in patients undergoing intervention.
• 4D flow V_Peak significantly predicted AV intervention (HR=2.51, p<0.01), whereas CWD V_Peak did not (HR=0.54, p=0.76).

Conclusions:

• 4D flow CMR-derived V_Peak assessment is superior to echocardiographic CWD assessment for predicting the timing of AV intervention.
• 4D flow CMR offers improved accuracy in assessing AS severity and guiding intervention decisions.
• This study supports the clinical utility of 4D flow CMR in managing patients with aortic stenosis.