The relationship between native T1 and mortality in patients requiring maintenance haemodialysis, using cardiac magnetic resonance imaging.

BACKGROUND

In people with kidney failure requiring haemodialysis, sudden cardiac death and arrhythmia are prevalent causes of mortality, driven by left ventricular (LV) hypertrophy and myocardial fibrosis. Native T1, a non-contrast magnetic resonance imaging (MRI) technique, is thought to represent myocardial fibrosis in this population. We hypothesised that MRI measures of cardiac structure and function would associate with mortality.

METHODS

A post-hoc, longitudinal analysis of data from the CYCLE-HD (ISRCTN11299707) and TICKER (NCT03704701) studies examined associations between native T1, LV mass index, LV ejection fraction (LVEF), and mortality over five years in people requiring haemodialysis. Cox proportional hazard models were adjusted for age, sex, diabetes, time on dialysis, and subsequent transplant.

RESULTS

Among 156 participants (mean age 60, 71% [111/156] male), 71 died over five years. In adjusted models increases in T1, LV mass index, and decreases in LV ejection fraction independently associated with mortality. A 30 ms increase in native T1 conferred a 27% increased risk of death. A 1 g/m2 increase in LV mass index increased mortality risk by 2%. Each 1% increase in LVEF reduced mortality risk by 3%. In an exploratoryadjusted model that included native T1, LVMi and LVEF, only LVMi remained an independent determinant of mortality.

CONCLUSION

Native T1, LV mass index, and LVEF were significant determinants of mortality in people requiring haemodialysis. T1 shows promise as a novel biomarker of myocardial fibrosis in this population. Associations between changes in T1 and mortality, and consideration of implementing findings into clinical practice needs research.