Abstract 13855: Electrophysiological Substrate and Risk of Mortality in Incident Hemodialysis Patients: Predictors of Arrhythmic and Cardiovascular Risk in End-Stage Renal Disease (PACE) Study

Abstract

Introduction: Mortality in end-stage renal disease (ESRD) patients on dialysis is high; sudden cardiac death is the leading cause. Hypothesis: Left ventricular hypertrophy (LVH), late potentials on signal averaged ECG (SAECG) and wide spatial QRS-T angle are independently associated with mortality in incident hemodialysis patients. Methods: SAECGs were recorded at baseline (within 3-6 months of start of dialysis) in 360 participants [mean age 57.2±13.4 y; 59% male; 73% black; mean left ventricular (LV) ejection fraction (EF) 65.5±12.1%] from the Predictors of Arrhythmic and Cardiovascular Risk in End Stage Renal Disease study, a prospective cohort of incident hemodialysis participants. Spatial mean QRS-T angle was measured on an averaged beat. ECG-LVH was defined as sex-adjusted Cornell product >2440 mm*ms. Echo-LVH was defined as LV mass index >131 g/m2 (M); >113 g/m2 (F). Late potentials were detected on SAECG. All-cause mortality is the primary outcome. Results: During 2.4±1.3 years of follow-up, 75 patients died. Cumulative unadjusted mortality was higher in participants with QRS-T angle ≥ 75° (Figure). In Cox regression analyses, stratified by presence of bundle branch block, QRS-T angle ≥ 75° was associated with a greater than two-fold increase in risk for mortality after adjustment for age, sex, race, and BMI [HR 2.62(1.53-4.48); P<0.001]. The association remained significant after the addition to the model: 1) diabetes and prevalent cardiovascular disease [2.47(1.44-4.23); P=0.001], 2) LVEF, QRS duration, and LVH [2.64(1.53-4.55); P<0.0001], and 3) averaged 90-day serum albumin and creatinine [HR 2.29(1.28-4.10); P=0.005]. Abnormal SAECG, ECG-LVH and Echo-LVH were not associated with mortality. Conclusions: Spatial QRS-T angle, but not late potentials on SAECG or LVH, is independently associated with mortality after adjustment for both traditional and dialysis-related cardiovascular risk factors in incident hemodialysis.