MR 4D flow-derived left atrial acceleration factor for differentiating advanced left ventricular diastolic...

Area of Science:

• Cardiovascular Imaging
• Medical Physics
• Diagnostic Cardiology

Background:

• Left ventricular (LV) diastolic dysfunction diagnosis is complex and multi-parametric.
• Non-invasive estimation of left atrial (LA) pressure is crucial for assessing diastolic dysfunction.
• The LA acceleration factor α derived from 4D flow imaging is a novel parameter for estimating LA pressure.

Purpose of the Study:

• To investigate the association between the 4D flow-derived LA acceleration factor α and the severity of LV diastolic dysfunction.
• To evaluate the diagnostic performance of α in differentiating grades of LV diastolic dysfunction using echocardiography as a reference.

Main Methods:

• Prospective study of 94 subjects undergoing echocardiography and 3-T cardiac MR 4D flow imaging.
• Calculation of LA acceleration factor α using peak outflow and inflow velocities from 4D flow data.
• Receiver operating characteristic (ROC) curve analysis to determine the diagnostic accuracy of α for diastolic dysfunction.

Main Results:

• Mean α values increased significantly with higher grades of LV diastolic dysfunction (p < 0.001).
• α demonstrated high accuracy in detecting advanced diastolic dysfunction (AUC = 0.998), with 100% sensitivity and 99% specificity at α ≥ 1.58.
• α accurately differentiated grade III diastolic dysfunction (AUC = 0.998) at α ≥ 2.14.

Conclusions:

• The 4D flow-derived LA acceleration factor α effectively distinguishes advanced (grade II and III) LV diastolic dysfunction from non-advanced grades.
• α serves as a single, continuous parameter that can simplify the diagnostic algorithm for advanced LV diastolic dysfunction.
• This parameter holds potential for identifying patients at increased risk of cardiovascular events.