AMBULATORY BLOOD PRESSURE LEVELS AFFECT THE ASSOCIATION OF INTRADIALYTIC HYPERTENSION WITH ADVERSE CARDIOVASCULAR EVENTS IN HEMODIALYSIS PATIENTS

Abstract

Objective: Patients with intradialytic hypertension (IDH) display also higher ambulatory blood pressure (BP) levels during the whole 44-h interdialytic interval compared to patients without the phenomenon. Sustained high 44-h ambulatory BP levels is a potential risk factor for cardiovascular events and mortality in these individuals. The aim of this study is to evaluate the influence of elevated 44-h BP levels on the high cardiovascular risk of individuals with IDH. Design and method: A total of 242 hemodialysis patients with valid 48-h ABPM with Mobil-O-Graph-NG had an extended follow up for a median of 57.8 months. IDH was defined as: rise in SBP greater or equal to 10 mmHg from pre- to post-dialysis and post-dialysis SBP greater or equal to 150 mmHg. The primary end-point was a composite of cardiovascular death, non-fatal myocardial infarction, non-fatal stroke, resuscitation after cardiac arrest, hospitalization for heart failure, coronary or peripheral revascularization procedure. The secondary endpoint was cardiovascular mortality. Results: 45 patients with and 197 without were included in this prospective analysis. Cumulative freedom from the primary and secondary endpoint was significantly lower for patients with IDH (logrank-p = 0.019), while freedom from the secondary endpoint did not differ significantly between the two groups (logrank-p = 0.321). Patients with IDH presented a significantly higher risk for the composite endpoint (HR = 1.651, 95%CI[1.083, 2.516]), without, however, showing a significant difference in the risk for cardiovascular mortality (HR = 1.320, 95%CI[0.762, 2.288]). After adjustment for 44-h SBP, the association of IDH with the primary endpoint slightly attenuated, while the association with the secondary outcome had no significant changes (HR = 1.421, 95%CI[0.906, 2.228] and HR = 1.270, 95%CI[0.708, 2.276], for primary and secondary outcome respectively). Conclusions: IDH is associated with higher risk for adverse cardiovascular outcomes. High ambulatory BP during the interdialytic interval contributes to the excess cardiovascular risk observed in this population.