The Effects of Nebivolol and Irbesartan on Ambulatory Aortic Blood Pressure and Arterial Stiffness in Hemodialysis Patients with Intradialytic Hypertension.

ABSTRACT

BACKGROUND: Intradialytic hypertension occurs in 5-15% of hemodialysis patients and is associated with increased cardiovascular risk, but the responsible mechanisms remain unknown. This study examined the effects of nebivolol and irbesartan on ambulatory central blood pressure (BP), arterial stiffness, and wave-reflection parameters in patients with intradialytic hypertension. METHODS: This is a prespecified analysis of a single-blind, randomized, cross-over study in 38 hemodialysis patients with intradialytic hypertension. Patients were randomized to nebivolol 5 mg followed byirbesartan 150 mg, or vice versa. In a non-randomized manner, the first half of the patients (n = 19) received a single drug dose 1 h prior to dialysis session and the remaining received the drugs for a whole week before the evaluation. Ambulatory central BP, arterial stiffness, and wave-reflection parameters were estimated with Mobil-O-Graph NG device, during a midweek dialysis day. RESULTS: Intake of a single dose of nebivolol or irbesartan resulted in lower postdialysis central systolic BP (c-SBP) (baseline 140.9 ± 15.4; nebivolol 130.3 ± 19.5, p = 0.009; irbesartan 127.3 ± 24.4 mm Hg, p = 0.007). Single-dose nebivolol also produced marginally lower 24-h c-SBP (p = 0.064) and lower 24-h central diastolic BP (c-DBP) (p = 0.029). Weekly administration of both drugs reduced postdialysis c-SBP (baseline 144.1 ± 15.3; nebivolol 131.8 ± 14.1, p = 0.014; irbesartan 126.4 ± 17.8, p = 0.001) and 24-h c-SBP and c-DBP (baseline 135.5 ± 10.3/91.9 ± 9.2; nebivolol 126.4 ± 8.4/86.6 ± 7.2, p < 0.001/p = 0.002; irbesartan 128.7 ± 11.6/87.0 ± 9.4, p = 0.061/p = 0.051 mm Hg). Single-dose intake of both drugs did not affect heart rate-adjusted augmentation index [AIx(75)], but decreased postdialysis pulse wave velocity (PWV). Importantly, weekly administration of both drugs reduced 24-h PWV (baseline 10.0 ± 2.5; nebivolol 9.7 ± 2.5, p = 0.012; irbesartan 9.7 ± 2.7, p = 0.041). In between drug-group comparisons, no significant differences were noted. CONCLUSIONS: This is the first randomized evaluation on the effects of pharmacological interventions on central BP and PWV in patients with intradialytic hypertension. Weekly administration of both nebivolol and irbesartan reduced 24-h central BP and PWV, but not AIx(75).