Association of Ambulatory Blood Pressure with All-Cause Mortality and Cardiovascular Outcomes in Peritoneal Dialysis Patients

Background: Ambulatory blood pressure monitoring is the gold standard for the diagnosis of hypertension, but its effects on all-cause mortality and cardiovascular outcomes in peritoneal dialysis (PD) patients remain uncertain. We aimed to investigate the association between ambulatory blood pressure and clinical outcomes in PD patients. Methods: A prospective, observational cohort study was conducted in PD patients enrolled from March 2001 to July 2018 and followed until October 2019. Blood pressure was evaluated using 24-h ambulatory blood pressure monitoring. The endpoints included all-cause mortality, cardiovascular mortality, and cardiovascular events. Multivariable Cox regression was used to identify the associations between ambulatory blood pressure and endpoints. Subsequently, multivariable logistic regression was conducted to identify factors associated with elevated pulse pressure (PP). Results: A total of 260 PD patients (154 men, 59.2%) were recruited. The median follow-up duration was 40.7 months. Our studies revealed that PP was an independent predictor of all-cause mortality (hazard ratio [HR], 1.018; 95% CI, 1.001-1.034; p = 0.032), cardiovascular mortality (HR, 1.039; 95% CI, 1.017-1.061; p < 0.001), and cardiovascular events (HR, 1.028; 95% CI, 1.011-1.046; p = 0.001). Systolic blood pressure was an independent predictor of cardiovascular mortality (HR, 1.023; 95% CI, 1.007-1.040; p = 0.005) and cardiovascular events (HR, 1.018; 95% CI, 1.006-1.030; p = 0.003). Vascular calcification was significantly associated with elevated PP (OR, 3.069; 95% CI, 1.632-5.772; p = 0.001). Conclusion: 24-h ambulatory PP was the most significant predictor of all blood pressure indicators for clinical outcomes in PD patients.