Right ventricular dyssynchrony in pulmonary hypertension: Phase analysis using FDG-PET imaging

Area of Science:

• Cardiology
• Nuclear Medicine
• Medical Imaging

Background:

• Right ventricular (RV) performance is crucial in pulmonary hypertension (PH) and requires accurate assessment.
• Current methods for evaluating RV function and dyssynchrony in PH may have limitations.
• ¹⁸F-fluorodeoxyglucose positron emission tomography (FDG-PET) offers a potential advanced imaging modality.

Purpose of the Study:

• To develop and validate FDG-PET phase analysis for assessing RV mechanical dyssynchrony in PH patients.
• To compare FDG-PET derived measurements with echocardiography.
• To investigate the correlation between RV dyssynchrony and RV dysfunction markers.

Main Methods:

• Fifty-four PH patients underwent FDG-PET imaging for RV phase analysis and RV function evaluation.
• Echocardiography with speckle tracking was used to measure RV time to peak systolic strain (PSST) for comparison.
• RV phase analysis derived parameters like RVPD_PET, RV phase standard deviation (RVSD), and histogram bandwidth (RVBW) were calculated.

Main Results:

• FDG-PET phase analysis demonstrated a significant correlation with echocardiography in measuring contraction delays (RVPD_PET vs. RVPD_Echo, r=0.685).
• RVSD and RVBW derived from FDG-PET phase analysis showed significant correlations with cardiac index, RV ejection fraction, 6-minute walking distance, and NT-proBNP levels.
• No significant correlations were found between RVSD/RVBW and hemodynamic parameters.

Conclusions:

• FDG-PET phase analysis is a feasible and reliable method for evaluating RV mechanical dyssynchrony in PH.
• The degree of RV dyssynchrony measured by FDG-PET is significantly associated with RV dysfunction.
• This technique provides valuable insights into RV performance in PH patients.