Retinal microperfusion after renal denervation in treatment-resistant hypertensive patients.
BACKGROUND
High pulsatile pressure and flow in the arteries causes microvascular damage, and hence increased cardio-, and cerebrovascular complications. With advanced stages of hypertensive disease, an exaggerated pulsatile retinal capillary flow (RCF) has been shown, but data about interventional effect are missing.


METHODS
Fifty-one patients with true treatment-resistant hypertension (TRH) underwent renal denervation (RDN) using the Symplicity Flex(™) catheter and were followed for 12 months. RCF was assessed non-invasively using Scanning laser Doppler flowmetry (SLDF) before, 6 (6 M), and 12 (12 M) months after RDN. RCF was measured in systole and diastole and pulsed RCF (difference of RCF in systole minus diastole) was calculated. In addition, flicker light-induced vasodilation (representing vasodilatory capacity) was assessed.


RESULTS
Systolic and diastolic office blood pressure (BP) as well as 24-h ABPM decreased significantly 6 M and 12 M after RDN, compared to baseline values (all p < 0.001). There was a significant reduction of pulsed RCF 6 M (231 ± 81 versus 208 ± 68 AU, p = 0.046) and 12 M (194 ± 72 AU, p = 0.001) after RDN, whereas the mean RCF was unchanged. Moreover, there was a significant increase of flicker light-induced vasodilation after RDN (p = 0.043).


CONCLUSIONS
In hypertensive patients with TRH, we observed a decrease of pulsed RCF 6 M and 12 M after RDN and an increase of vasodilatory capacity, in parallel to decreases in BP and heart rate. The reduction of pulsed RCF after RDN implies a decrease of shear stress on the vascular wall by the pulsed blood flow. This and the increment of vasodilatory capacity suggest an improvement of retinal (and potentially cerebral) microcirculation.
Department of Nephrology and Hypertension, Friedrich-Alexander University Erlangen-Nürnberg, Ulmenweg 18, 91054, Erlangen, Germany.
Christian
C
Ott
Joanna M
JM
Harazny
Axel
A
Schmid
Tilmann
T
Ditting
Roland
R
Veelken
Marek
M
Bladowski
Georg
G
Michelson
Michael
M
Uder
Roland E
RE
Schmieder
D000368:Aged; D000959:Antihypertensive Agents / Q000627:therapeutic use; D017763:Autonomic Denervation; D001783:Blood Flow Velocity; D001794:Blood Pressure / Q000187:drug effects; D018660:Blood Pressure Monitoring, Ambulatory; D002196:Capillaries / Q000503:physiopathology*; D004351:Drug Resistance; D005260:Female; D006339:Heart Rate; D006801:Humans; D006973:Hypertension / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery*; D007668:Kidney / Q000294:innervation*; D017078:Laser-Doppler Flowmetry; D008297:Male; D008833:Microcirculation; D008875:Middle Aged; D010775:Photic Stimulation; D011673:Pulsatile Flow; D012039:Regional Blood Flow; D012171:Retinal Vessels / Q000503:physiopathology*; D013997:Time Factors; D016896:Treatment Outcome; D014664:Vasodilation
D000959:Antihypertensive Agents