Abstract: FR-PO851

Defining the Extent of Replacement Myocardial Fibrosis in Hemodialysis Patients with Non-Contrast Cardiac Magnetic Resonance

Session Information

Category: Dialysis

  • 606 Dialysis: Epidemiology, Outcomes, Clinical Trials - Cardiovascular

Authors

  • Graham-Brown, Matthew P.M., University Hospitals Leicester, Leicester, United Kingdom
  • March, Daniel Scott, University of Leicester, Leicester, United Kingdom
  • Burton, James, University of Leicester, Leicester, United Kingdom

Group or Team Name

  • CYCLE-HD
Background

Extent of replacement myocardial fibrosis predicts patient mortality in advanced renal disease. Gadolinium enhanced cardiac MRI (CMR) defines myocardial fibrosis in disease groups with normal renal function, but is not possible in patients with advanced renal disease due to the risk of nephrogenic systemic fibrosis. In this study we describe and assess a non-contrast native T1 CMR signal thresholding technique (T11SD) that may be used for the detection and quantification of myocardial scar burden in haemodialysis (HD) patients.

Methods

The T11SD technique defines the mean native T1 and standard deviation (SD) in regions of discretely increased signal on native T1 parametric maps. The mean +/- SD of the region of interest are then applied as a threshold to the entire myocardium to give a threshold percentage. We assessed the agreement between T11SD and late gadolinium enhanced CMR (LGE-CMR) defined myocardial scarring (using full width half maximum analysis) in patients with aortic stenosis (AS) (n=25). We then compared T11SD between patients with AS (n=25) and patients on HD (n=25) and assessed inter-and intra-observer variability of T11SD in HD patients (n=10).

Results

Myocardial scar assessed by LGE-CMR correlated with T11SD in AS patients (r=0.913) with moderate agreement (ICC=0.55). Bland-Altman showed T11SD systematically overestimated scar burden by 4.3% compared to LGE-CMR. Extent of myocardial scarring defined by T11SD was higher in HD patients compared to AS patients (21.92%±1.0 vs 18.24%±1.4). Global native T1 time was higher in HD patients compared to AS patients (1279ms±5.8 vs 1143ms±12.49) as was the region of interest defined as scar (1390±8.7 vs 1276ms±20.5). The difference between remote myocardium and regions defined as scar were no different between groups (111.4ms±7.6 vs 133.2ms±17.5) representing a 9.6% and 10.4% increase from background myocardium. Inter-and intra-observer variability of T11SD were excellent (ICC=0.87, and 0.96).

Conclusion

This study suggests that extent of replacement myocardial fibrosis can be defined quantitatively with the native T1 signal intensity thresholding technique T11SD in HD patients, which we describe for the first time. This has important implications for the assessment and risk stratification in future research and clinical practice.

Funding

  • Other NIH Support