Assessment of Left Ventricular Diastolic Function Using Hemodynamic Forces From Cardiac Magnetic Resonance Imaging (RF_FR_398)

A novel approach of Cardiac Magnetic Resonance Imaging (CMR) is the assessment of ventricular hemodynamic forces (HDF) that can amplify mechanical abnormalities, detect them earlier compared to conventional analysis of ejection fraction and strain, and possibly predict the development of cardiac remodeling. Its close relationship between blood flow and myocardial tissue provides the overall cardiac performance during a complete cardiac cycle and its different phases are also possible.


Diastolic function involves ventricular filling, and any measurement of diastolic function must be performed with knowledge of the determinants of ventricular filling and the limitation of the diagnostic test.

Objective:
The aim of this study is to evaluate the performance of diastolic function across ventricular filling phases by HDF CMR as a predictor of cardiovascular events.  



Methods:

We retrospectively analyzed patients undergoing regular CMR using feature tracking to measure left ventricular Global Longitudinal Strain (GLS) and calculate HDF using the software Medis Suite 4.4 QStrain with the HDF add-on.

This method quantifies the intraventricular pressure gradients from Apex-to-Base (HDF A-B); Lateral-to-Septal (HDF L-S); orientation Angle from intensity – weighted polar histogram (HDF Angle) and Ratio between the transverse force and longitudinal force (HDF Ratio) throughout the cardiac cycle. Figure 1.

We focused on the assessment of LV HDF Diastolic phases a) Systolic Slowdown (HDF B1) & b) Diastolic Suction (HDF B2) as a highlight of diastolic function. Figure 2.

Follow-up was performed between 2015 and 2024 to assess the primary endpoint of Cardiac Death, Hospitalization for Heart Failure and Myocardial Infarction. Statistical analyses were performed using Jamovi (Version 2.5.2). Continuous variables are presented as mean ± standard deviation (if normally distributed) or median (interquartile range) if not normally distributed. Categorical variables are presented as total number (percentage). P-value < 0.05 was considered statistically significant



Results:

We included 149 patients with a mean age of 54 ± 15 years, 65% were male with pathological history, 41% were hypertensive, 10% diabetic and 35% dyslipidemic.

Left Ventricle Ejection Fraction (LVEF) = 58% (15%); GLS= -21.1% (-7.27%); Throughout the cardiac cycle HDF A-B= 14% (8.3%); HDF L-S= 2.68 % (1.31%); HDF Angle= 72º (6º); HDF Ratio= 20.2 % (8.7%) and diastolic phase HDF B1= -7% (-4.83%); HDF B2= - 8,79% (-7,49%).

Of all patients, 30 (20 %) had the primary endpoint during follow-up.

These patients had for HDF B1 & HDF B2 an odds ratio of 1.33 (CI 1.14 -1.54) p=0.001; 1.2 (CI 1.09 - 1.32) p=0.001 respectively with a cutoff point for HDF B1 -5.9%, specificity of 72% and sensitivity of 71% (AUC=0.79) and for HDF B2 -2.3%, specificity of 72.6% and sensitivity of 71.9% (AUC=0.79) Figure 3.



Conclusion: We found a practical tool for the evaluation of diastolic function by Hemodynamic Forces in the diastolic filling phases by CMR, allowing a solid prediction of cardiovascular events in our population.