Diffuse interstitial fibrosis and myocardial dysfunction in early chronic kidney disease

Area of Science:

• Cardiology
• Nephrology
• Medical Imaging

Background:

• Early-stage chronic kidney disease (CKD) is an under-recognized cardiovascular (CV) risk factor.
• Nonatherosclerotic processes like left ventricular (LV) hypertrophy and fibrosis are hypothesized to contribute significantly to excess CV risk in CKD.

Purpose of the Study:

• To investigate the presence and extent of diffuse myocardial fibrosis in early-stage CKD patients.
• To assess the association between myocardial fibrosis and cardiac function, particularly global longitudinal strain.
• To compare cardiac findings in CKD patients with hypertensive individuals and healthy controls.

Main Methods:

• Cross-sectional observational study of 129 participants (CKD stages 2-4, hypertensive, healthy controls).
• Cardiac magnetic resonance imaging (CMR) used for LV volumes, systolic function, and myocardial deformation assessment.
• T1 mapping and extracellular volume (ECV) quantification employed to assess diffuse myocardial fibrosis.

Main Results:

• Patients with CKD exhibited increased native T1 times and ECV, indicating diffuse myocardial fibrosis, compared to controls and hypertensive subjects.
• Increased T1 times and ECV correlated with impaired global longitudinal systolic strain, a marker of reduced systolic function.
• No significant differences were observed in LV volumes, ejection fraction, or LV mass across groups.

Conclusions:

• Diffuse myocardial fibrosis is prevalent in early-stage CKD and is associated with early signs of cardiac dysfunction (abnormal global longitudinal strain).
• These findings suggest diffuse fibrosis is a key component of uremic cardiomyopathy and a predictor of adverse cardiovascular outcomes in CKD.