Impact of pericardial fat volume on myocardial inflammation assessed by quantitative T2 relaxation time using cardiac magnetic resonance imaging

Abstract Background Pericardial fat is metabolically active and has been linked to local myocardial inflammation. It correlates with inflammatory and haemostatic biomarkers, including a positive association with interleukin-6 (IL-6) levels. Cardiac MRI–derived T2 relaxation time reflects myocardial inflammation and oedema, but its relationship with pericardial fat volume (PFV) remains unclear. Understanding this association may help clarify mechanisms of fat-related myocardial injury and cardiovascular risk. Purpose To investigate the association between PFV and myocardial inflammation, as assessed by T2 relaxation time on cardiac MRI. Methods This cross-sectional study included patients with coronary artery disease and heart failure with preserved ejection fraction (HFpEF), without evidence of scar on late gadolinium enhancement (LGE) imaging. Imaging was performed between November 2023 and December 2024 using a 1.5T MRI scanner. T2 relaxation time was measured from three short-axis slices using T2-prepared balanced steady-state free precession sequences. PFV was calculated as the volume difference between the pericardial and myocardial borders on short-axis images. Additional volumetric measurements followed the Society for Cardiovascular Magnetic Resonance (SCMR) guidelines. Patients were categorised by T2 relaxation time into prolonged (≥55 ms) and normal (