Evolving Myocardial Injury in Chronic Kidney Disease Assessed by Multiparameter Magnetic Resonance in a Rabbit Model.

Abstract

Background: Early diagnosis and monitoring of chronic kidney disease (CKD)-related myocardial injury are crucial for improving outcomes.

Purpose: To evaluate myocardial tissue characteristics and deformation during the occurrence and evolution of CKD in a rabbit model using multiparametric cardiac MRI.

Study type: Longitudinal animal study.

Population: A total of 26 rabbits (14 undergoing cationic bovine serum albumin (C-BSA) injection to induce CKD, 12 undergoing sham saline injection to serve as controls).

Field strength/sequence: 3, cine, T1 mapping, and T2 mapping sequences.

Assessment: Cardiac MRI was performed at baseline, 4, 6, and 8 weeks in both groups. Global radial, circumferential, and longitudinal strain (GRS, GCS and GLS, respectively), native T1, T2, and extracellular volume (ECV) were assessed at each time point. Collagen volume fraction (CVF) was assessed, and immunohistochemical staining was performed using the IL-6 antibody. Pathology was used as a reference standard for comparison with MRI findings. The diagnostic accuracy of individual and combined MR parameters for detecting early CKD-related myocardial injury was determined.

Statistical tests: Descriptive statistics, Spearman correlation (r), area under the receiver operating characteristic curve (AUC). A p-value < 0.05 was considered statistically significant.

Results: Compared to controls, GLS was significantly lower, and ECV was significantly higher in the CKD group at 4 weeks post-injection. At 6 and 8 weeks, GLS was further reduced, and native T1, T2, and ECV values were significantly increased in the CKD group compared to controls. Myocardial native T1 and ECV were significantly positively correlated with CVF (r = 0.584 and 0.754, respectively), and T2 was significantly positively correlated with IL-6 (r = 0.661). The combination of native T1 and GLS showed superior diagnostic accuracy for detecting early CKD-related subclinical myocardial injury compared to single indicators (AUC = 0.846, 95% CI: 0.731-0.962).

Conclusions: The appropriate combination of cardiac MRI-based features of strain, fibrosis, and inflammation may serve as an early marker of CKD-related myocardial injury.

Evidence level: N/A.

Technical efficacy: Stage 2.