Effects of Enhanced Versus Reduced Vasodilating Treatment on Brachial and Central Blood Pressure in Patients with Chronic Kidney Disease: a Randomized Controlled Trial.

Background: Blood pressure (BP) control is important in chronic kidney disease (CKD), but a reduction in brachial BP may not mirror changes in central aortic BP (cBP) during antihypertensive medication. We hypothesize that a fall in cBP is better reflected during enhanced vasodilation treatment (EVT) compared with reduced vasodilation treatment (RVT) because of different hemodynamic actions of these interventions. Methods: Eighty-one hypertensive CKD stage 3-4 patients (mean measured glomerular filtration rate 36 ml/min per 1.73 m(2)) were randomized to either EVT based on renin--angiotensin blockade and/or amlodipine or RVT based on nonvasodilating beta-blockade (metoprolol). Before randomization and following 18 months of treatment, we performed 24-h ambulatory BP measurements (ABPM) and radial artery pulse wave analysis for estimation of cBP and augmentation index (AIx). Forearm resistance (R-rest) was determined by venous occlusion plethysmography and arterial stiffness by carotid--femoral pulse wave velocity (PWV). Matched healthy controls were studied once for comparison. Results: Compared with controls, CKD patients had elevated ABPM, cBP and PWV. Although ABPM remained unchanged from baseline to follow-up in both treatment groups, cBP decreased 4.7/2.9 mmHg (systolic/diastolic) during EVT and increased 5.1/1.5 mmHg during RVT (Delta=9.8/4.4 mmHg, P=0.02 for SBP, P = 0.05 for DBP). At follow-up, the difference between systolic cBP and 24-h ABPM (Delta BPsyst) was negatively associated with heart rate and positively associated with AIx and R-rest (all P < 0.01) but not PWV (P = 0.32). Conclusion: In CKD patients, EVT and RVT have opposite effects on cBP and the difference between cBP and ambulatory BP is larger for EVT than RVT.