HOME BLOOD PRESSURE IS AN INDEPENDENT PEDICTOR OF ALL-CAUSE MORTALITY IN HEMODIALYSIS PATIENTS: A PROSPECTIVE OBSERVATIONAL STUDY

Objective: Unlike the general population, prior studies conducted in hemodialysis patients have demonstrated that lower, but not higher, dialysis-unit blood pressure (BP) is associated with worse clinical outcomes. The present study aimed to investigate the prognostic association of home BP with all-cause mortality in hemodialysis patients. Design and method: A prospective observational study was conducted in 146 patients receiving hemodialysis in 3 centers of Northern Greece. At baseline, patients underwent assessment of their BP with the following methods: (i) routine predialysis and postdialysis BP recordings averaged over 6 consecuitive dialysis sessions; (ii) home BP monitoring with a validated oscillometric arm device (duplicate morning and evening measurements) over 1 week. Patients were prospectively followed for a median period of 38 months to assess the endpoint of all-cause mortality. Results: A total of 146 hemodialysis patients (100 males) with a mean age of 63.8±13.9 years and a median dialysis vintage of 22 months (interquartile range: 10-58) were enrolled in the study. During the follow-up period, 44 patients (30.1%) died. In Kaplan-Meier curves, whereas predialysis and postdialysis systolic BP had no association with all-cause mortality, home systolic BP appeared to be of prognostic significance. When patients were stratified into quartiles, all-cause mortality was lowest when home systolic BP was ranging between 128.1 and 136.8 mmHg (quartile 2). In unadjusted models, using quartile 2 of home systolic BP as a referent category, the risk of all-cause mortality was 3.32-fold higher in quartile 1 [hazard ratio (HR): 3.32; 95% confidence interval (CI): 1.18-9.32], 1.53-fold higher in quartile 3 (HR: 1.53; 95% CI: 0.49-4.84) and 3.25-fold higher in quartile 4 (HR: 3.25; 95% CI: 1.21-8.71). This risk-association remained unmodified after adjustment for age, gender, dialysis vintage, and several additional risk factors (adjusted HR: 4.79, 1.79, 3.63 for quartiles 1, 3 and 4 of home systolic BP, respectively). Conclusions: The present study shows that among patients on hemodialysis, home systolic BP is prognostically more informative than predialysis and postdialysis systolic BP. 1-week averaged home systolic BP of 128.1 to 136.8 mmHg is associated with the best survival in this high-risk patient population.