Mechanisms Underlying Vascular Endothelial Growth Factor Receptor Inhibition-Induced Hypertension: The HYPAZ Trial

[Figure: see text].

Effects of additional vasodilatory or nonvasodilatory treatment on renal function, vascular resistance and oxygenation in chronic kidney disease: a randomized clinical trial

AIM

Progression of chronic kidney disease (CKD) may be accelerated by tissue hypoxia due to impaired blood supply. This could be induced by small artery narrowing resulting in abnormally high intrarenal vascular resistance (RVR). We investigated whether a reduction in RVR achieved by adding vasodilating medical therapy (AVT) is superior to adding nonvasodilating medical therapy (AnonVT) regarding tissue oxygenation and preservation of kidney function.

METHODS

Eighty-three grade 3 and 4 CKD patients [estimated glomerular filtration rate (GFR) 34.6 ml/min per 1.73 m] were randomized to either AVT with amlodipine and/or renin angiotensin blockade or AnonVT with the nonvasodilating beta-blocker metoprolol. Investigations were performed at baseline and after 18 months of therapy. Systemic vasodilation was documented in the forearm vasculature using resting venous occlusion plethysmography. GFR was measured as Chrome-EDTA plasma clearance. Using MRI, renal artery blood flow was measured for calculation of RVR and for estimating renal oxygenation (R2*).

RESULTS

AVT and AnonVT achieved as planned similar blood pressure levels throughout the study. At follow-up, resistance had decreased by 7% (P < 0.05) and RVR by 12% (P < 0.05) in the AVT group, whereas in the AnonVT group, resistance increased by 39% (P < 0.01), whereas RVR remained unchanged. At follow-up, no significant differences in cortical or medullary R2* values between AVT and AnonVT were observed, and the GFR decline was similar in the two groups (3.0 vs. 3.3 ml/min per 1.73 m).

CONCLUSION

Long-term intensified vasodilation treatment reduced peripheral and RVR, but this was not associated with improvement of R2* or protection against loss of kidney function in CKD patients.

Arterial stiffness and peripheral vascular resistance in offspring of hypertensive parents: influence of sex and other confounders

AIM

Established essential hypertension is associated with increased arterial stiffness and peripheral resistance, but the extent of vascular changes in persons genetically predisposed for essential hypertension is uncertain.

METHODS

Participants from the Danish Hypertension Prevention Project (DHyPP) (both parents hypertensive) (n = 95, 41 ± 1 years, 53% men) were compared with available spouses (n = 45, 41 ± 1 years) using measurements of ambulatory blood pressure (BP), left ventricular mass index (LVMI), pulse wave velocity, central BP and augmentation index (AIx) in addition to forearm resting and minimal resistance [forearm resting vascular resistance (Rrest) and forearm minimal vascular resistance (Rmin)].

RESULTS

DHyPP patients with participating spouses had higher 24-h mean BP (94 ± 1 vs. 88 ± 1 mmHg, P < 0.01), LVMI (94 ± 3 vs. 80 ± 2 g/m, P < 0.01), central SBP (121 ± 2 vs. 111 ± 2 mmHg, P < 0.01) and AIx (16.0 ± 1.2 vs. 10.5 ± 1.7%, P < 0.01), but similar carotid-femoral pulse wave velocity (7.5 ± 0.2 vs. 7.1 ± 0.2 m/s), Rrest (53 ± 3 vs. 51 ± 3 mmHg/ml/min/100 ml) and log Rmin (0.58 ± 0.02 vs. 0.55 ± 0.02 mmHg/ml/min/100 ml) when compared with spouses. Using multiple linear regression analysis (adjusting for sex, age, BMI, creatinine clearance and 24-h BP, heart rate and sodium excretion) AIx and LVMI remained elevated in DHyPP patients [4.2% (0.7; 7.7), P = 0.02 and 6.3 g/m (0.7; 11.9), P = 0.03]. For the entire DHyPP cohort AIx, Rrest and Rmin were higher in women than men (P < 0.01), and the same was true for AIx and Rmin among spouses (P < 0.05). Furthermore, AIx was linearly associated with Rrest and Rmin.

CONCLUSION

Young to middle-aged individuals genetically predisposed for essential hypertension display increased AIx and LVMI, although vascular stiffness and peripheral resistance are still normal.

The effect of renal denervation on arterial stiffness, central blood pressure and heart rate variability in treatment resistant essential hypertension: a substudy of a randomized sham-controlled double-blinded trial (the ReSET trial)

OBJECTIVES

To investigate, whether renal denervation (RDN) improves arterial stiffness, central blood pressure (C-BP) and heart rate variability (HRV) in patients with treatment resistant hypertension.

METHODS

ReSET was a randomized, sham-controlled, double-blinded trial (NCT01459900). RDN was performed by a single experienced operator using the Medtronic unipolar Symplicity Flex^TM catheter. C-BP, carotid-femoral pulse wave velocity (PWV), and HRV were obtained at baseline and after six months with the SphygmoCor^®-device.

RESULTS

Fifty-three patients (77% of the ReSET-cohort) were included in this substudy. The groups were similar at baseline (SHAM/RDN): n = 27/n = 26; 78/65% males; age 59 ± 9/54 ± 8 years (mean ± SD); systolic brachial BP 158 ± 18/154 ± 17 mmHg; systolic 24-hour ambulatory BP 153 ± 14/151 ± 13 mmHg. Changes in PWV (0.1 ± 1.9 (SHAM) vs. -0.6 ± 1.3 (RDN) m/s), systolic C-BP (-2 ± 17 (SHAM) vs. -8 ± 16 (RDN) mmHg), diastolic C-BP (-2 ± 9 (SHAM) vs. -5 ± 9 (RDN) mmHg), and augmentation index (0.7 ± 7.0 (SHAM) vs. 1.0 ± 7.4 (RDN) %) were not significantly different after six months. Changes in HRV-parameters were also not significantly different. Baseline HRV or PWV did not predict BP-response after RDN.

CONCLUSIONS

In a sham-controlled setting, there were no significant effects of RDN on arterial stiffness, C-BP and HRV. Thus, the idea of BP-independent effects of RDN on large arteries and cardiac autonomic activity is not supported.