Association between pulse pressure and 30-month all-cause mortality in peritoneal dialysis patients

Pulse pressure (PP) is an independent predictor of cardiovascular and/or all-cause mortality in patients with underlying cardiovascular disease. We examined whether PP can be used to predict overall mortality in peritoneal dialysis (PD) patients.

We studied 153 PD patients (mean age, 54.5 +/- 14.2 years) with end-stage renal disease. PP was measured monthly for 3 months. At the time of the third PP measurement, baseline demographic, clinical, biochemical, and dialysis data were collected. Patients were stratified into tertiles according to average PP, and the relationship between blood pressure parameters and all-cause mortality over a 30-month follow-up was assessed using Cox regression.

There were 27 deaths; three deaths occurred after the change to hemodialysis (HD) (subjects died within 3 months after HD) and were counted as events during survival analysis. The overall 30-month survival (Kaplan-Meier curves) times were significantly different among the tertiles of PP (P < 0.05). Increased PP was significantly associated with overall mortality regardless of adjustment for systolic blood pressure (SBP) or diastolic blood pressure (DBP).

PP may be the most consistent blood pressure indicator of mortality risk. All-cause mortality events in PD patients are more related to pulsatile stress caused by the stiffness of large arteries during systole (reflected in a rise of PP) than to steady-state stress stemming from resistance during diastole (reflected in a rise of SBP and DBP).