CMR Tissue Characterization in Patients with HFmrEF.

Area of Science:

• Cardiology
• Medical Imaging
• Heart Failure Research

Background:

• Heart failure with moderately reduced ejection fraction (HFmrEF, LV-EF 40-50%) remains poorly understood regarding its characteristics and optimal management.
• Advanced cardiac magnetic resonance imaging (MRI) provides insights into myocardial function, fibrosis, and inflammation, potentially aiding in HFmrEF characterization and adverse remodeling assessment.

Purpose of the Study:

• To characterize HFmrEF using cardiac MRI, focusing on myocardial fibrosis and inflammation.
• To compare cardiac MRI parameters in HFmrEF patients with those in heart failure with preserved ejection fraction (HFpEF), heart failure with reduced ejection fraction (HFrEF), and healthy controls.

Main Methods:

• Cardiac MRI was performed on 17 HFpEF, 18 HFmrEF, 17 HFrEF patients, and 17 healthy controls.
• T1 and T2 relaxation time mapping were used to assess myocardial tissue characteristics, and extracellular volume (ECV) was calculated.
• Global circumferential strain (GCS) and global longitudinal strain (GLS) were derived from cine images to evaluate systolic function.

Main Results:

• HFmrEF patients exhibited moderately reduced GLS (-15.7 ± 2.1) and GCS (-19.9 ± 4.1), indicative of systolic dysfunction.
• Native T1 relaxation times were elevated in HFmrEF (1027 ± 40 ms) and HFrEF (1033 ± 54 ms) compared to healthy controls (972 ± 31 ms) and HFpEF (985 ± 32 ms).
• T2 relaxation times were elevated in HFmrEF (55.4 ± 3.4 ms) and HFrEF (56.0 ± 6.0 ms) versus healthy controls (50.6 ± 2.1 ms); ECV differences were not statistically significant.

Conclusions:

• HFmrEF demonstrates distinct cardiac MRI findings compared to healthy controls, sharing similarities with HFrEF in terms of myocardial fibrosis and inflammation.
• Cardiac MRI parameters suggest that HFmrEF exhibits aspects of systolic dysfunction and myocardial tissue changes characteristic of fibrosis and inflammation.