Cardiovascular MRI predicts mortality in patients with end stage kidney disease

Background: Patients with end-stage kidney disease (ESKD) are at increased risk premature death, with cardiovascular disease being the predominant mode of death. We hypothesized that left ventricular global longitudinal strain (LV-GLS) measured by feature tracking cardiovascular magnetic resonance imaging (CMR) would be associated with all-cause mortality in patients with ESKD. Methods: A pooled analysis of CMR studies in patients with ESKD acquired within a single centre between 2002 and 2016 was carried out. CMR parameters including left ventricular ejection fraction (LVEF), LV mass index (LVMI), left atrial emptying fraction (LAEF) and LV-GLS were measured. We tested independent associations of CMR parameters with survival using a multivariable Cox model. Results: Among 215 patients (mean age: 54 years, 62% male), mortality was 53% over 5.0 years median follow-up. The median LVEF was 64.7% (IQR 58.5, 70.0) and median LV-GLS was -15.3% (-17.24, -13.6). While 90% of patients had preserved LVEF (>50%), 58% of this group had abnormal LVGLS (>-16%). On multivariable Cox regression, age (HR: 1.04, 95%CI: 1.02-1.05), future-renal transplant (HR 0.29 95%CI: 0.17-0.47), LAEF (HR: 0.98, 95%CI: 0.96-1.00) and LV-GLS (HR: 1.08, 95%CI: 1.01-1.16) were independently associated with mortality. Conclusions: In this cohort of patients with ESKD, LV-GLS on feature tracking CMR and LAEF were associated with all-cause mortality, independent of baseline clinical variables and future renal transplantation. This effect was present even when >90% of the cohort had normal left ventricular ejection fraction (LVEF). Using LV-GLS, instead of LVEF, to diagnose cardiac dysfunction in patients with ESKD could result in a major advance in our understanding of cardiovascular disease in ESKD.