Epicardial adipose tissue predicts mortality in incident hemodialysis patients: a substudy of the Renagel in New Dialysis trial.

BACKGROUND: Epicardial adipose tissue (EAT) has been described in the general population as an independent risk marker for incident coronary artery disease. In hemodialysis patients, it correlates with other markers of cardiovascular disease, but it is unknown if it is associated with adverse events.

METHODS: post hoc analysis of the Renagel in New Dialysis (RIND) patients study, a randomized trial of sevelamer versus calcium-based phosphate binders in 109 incident hemodialysis patients, followed for all-cause mortality for a median of 49.3 months. Patients underwent baseline cardiac computed tomography imaging within 120 days of dialysis initiation.

RESULTS: Baseline EAT measurements were available in 95 patients; EAT was positively correlated with age, body mass index, triglycerides, C-reactive protein, coronary artery calcium and aortic calcium, and negatively correlated with systolic and diastolic blood pressure, serum high density lipoprotein (HPL) cholesterol and serum phosphate (all P < 0.05). During follow-up, a total of 27 (28.4%) patients expired [mortality per 1000 patients/year: 95% confidence interval (95% CI) = 77 (64-94)]. Five-year survival rate was 44. 6% (95% CI: 21.1-65.7) and 71.2% (95% CI: 45.95-86.25) in patients with EAT above or below the median, respectively. Each 10 cc increase in EAT volume was associated with a significant 6% increase in the risk of death during follow-up [hazard ratio (HR): 1.060; 95% CI: 1.013-1.109; P-value = 0.012].

CONCLUSIONS: In this subanalysis of a randomized trial, EAT was an independent predictor of mortality in incident hemodialysis patients after ~4 years of follow-up. These hypothesis-generating findings will need confirmatory evidence.