Enhanced, reduced vasodilation treatments carry opposite effects on central aortic BP in CKD

Enhanced (EVT) and reduced vasodilation treatment (RVT) deliver contradictory impacts on central aortic blood pressure (cBP) in patients with chronic kidney disease (CKD), reports a study. Moreover, the difference between cBP and ambulatory BP is larger for EVT than RVT.

In this study, the researchers randomly assigned 81 hypertensive patients with stage 3–4 CKD (mean measured glomerular filtration rate 36 ml/min per 1.73 m²) to either EVT based on renin-angiotensin blockade and/or amlodipine or RVT based on nonvasodilating β-blockade (metoprolol). They also conducted 24-h ambulatory BP measurements (ABPM) and radial artery pulse wave analysis to estimate cBP and augmentation index (AIx) prior to randomization and after 18 months of treatment.

Forearm resistance (R_rest) was determined by venous occlusion plethysmography and arterial stiffness by carotid–femoral pulse wave velocity (PWV). In addition, the researchers assessed matched healthy controls for comparison.

CKD patients had elevated ABPM, cBP, and PWV compared with controls. ABPM did not change from baseline to follow-up in both treatment groups, but cBP decreased by 4.7/2.9 mm Hg during EVT and increased by 5.1/1.5 mm Hg during RVT (Δ=9.8/4.4 mm Hg; p=0.02 for SBP, p=0.05 for DBP).

During follow-up, the difference between systolic cBP and 24-h ABPM (ΔBP_syst) showed a negative correlation with heart rate and a positive correlation with AIx and R_rest (p<0.01 for all), but not PWV (p=0.32).

“BP control is important in CKD, but a reduction in brachial BP may not mirror changes in cBP during antihypertensive medication,” the researchers said.