Gadolinium-Enhanced Cardiac MRI Assessment of Uremic Cardiomyopathy in End-Stage Renal Disease: A Comparative Study

Background: Uremic cardiomyopathy (UC) is a common but often underdiagnosed cardiac complication in patients with end-stage renal disease (ESRD). However, based on our clinical experience differentiating it from myocardial inflammation or storage disease is challenging as UC is characterised by left ventricular hypertrophy, diastolic dysfunction and diffuse myocardial fibrosis. The latter is a strong predictor of cardiovascular mortality. Cardiac magnetic resonance imaging (CMR) is an excellent non-invasive method for the assessment of myocardial tissue.

Objective: The use of gadolinium-based contrast agents (GBCAs) in patients with severely impaired kidney function (GFR < 30 ml/min) or in dialysis patients has not been systematically analysed. The aim of the study is to evaluate myocardial tissue characteristics in ESRD patients using gadolinium-enhanced CMR (1,5 T, reduced dosis Gadoteric acid/Dotarem 0.1 mmol/kg body weight), and to compare the findings with those of patients for the same clinical indication but normal renal function.

Methods: We retrospectively analysed 32 patients with ESRD (defined as creatinine levels > 250 µmol/L, GFR < 30 ml/min or dialysis) and compared them with 32 control patients exhibiting normal renal function. Both groups were matched for the indication of cardiac MRI (clarification of a reduced LVEF, of coronary ischemia or suspected myocardial storage disease). There were no significant differences in age, sex, ejection fraction (EF) or prevalence of coronary artery disease (CAD) between the two groups (Table 1). All subjects underwent gadolinium-enhanced CMR with native T1 and T2 mapping (ROI was placed in basal or mid-ventricular septal myocardium of the left ventricle in areas without LGE) , extracellular volume (ECV) quantification, assessment of late gadolinium enhancement (LGE), and measurement of LV mass index (LV-MI). Bazetts QTc intervals were assessed via resting ECG.

Results: Compared to controls, ESRD patients demonstrated significantly higher diffuse myocardial fibrosis, as evidenced by elevated native T1 and particularly ECV values (Table 2). T2 values were within normal limits. LV-MI tended to be higher in ESRD patients than in controls. QTc intervals were significantly prolonged in the ESRD group (469 ± 47.3 ms vs. 445 ± 37 ms, p < 0.04). Notably, a myocardial biopsy was recommended more frequently after CMR in ESRD patients (25%) than in controls (6%) due to conspicuous LGE pattern. All biopsied ESRD patients showed histological signs of medium-grade interstitial fibrosis (mean fibrotic area 12.4%), consistent with uremic cardiomyopathy.

Conclusion: Gadolinium-enhanced CMR in ESRD patients reveals distinct myocardial alterations, indicative of diffuse interstitial fibrosis. The higher rate of biopsy referral suggests that myocardial changes in ESRD are more difficult to differentiate from inflammatory or infiltrative diseases. Prolonged QTc intervals in this group further support a potential link between structural remodeling and electrical instability in uremic cardiomyopathy. The myocardial patterns described here should be considered when interpreting CMR in ESRD patients to ensure accurate diagnosis and appropriate clinical decision-making.

Figure 1: Example of a patient with uremic cardiomyopathy in MRI (A, B): left ventricular hypertrophy (A, cine), diffuse intramural LGE (B, PSIR) and prominent myocardial fibrosis in histopathological findings (C, Mallory’s trichrome staining).