Early reduction of therapy-resistant hypertension in a patient after single-sided renal denervation approach

Abstract

Catheter-based renal denervation (RD) offers a relative new approach targeting the renal sympathetic nerves in order to decrease the blood pressure (BP) in patients with resistant hypertension associated with an increased risk of cardiovascular events. According to available evidence and expert suggestions, patients with treatment-resistant hypertension defined by office systolic BP C 160 mmHg (C 150 mmHg in type 2 diabetes) despite treatment with at least three antihypertensive drugs (including one diuretic) are eligible for RD [1, 2]. Secondary hypertension, including renal artery stenosis [ 50 %, must be ruled out and both-side denervation procedure is usually performed and some reports suggest higher responder rates in order to decrease the BP [3, 4]. Here, we report a RD procedure in a 47-year-old woman (BMI of 31.2 kg/m) with medically resistant hypertension on a treatment of seven antihypertensive drugs (b-blocker, angiotensin-II-blocker, calcium channel blocker, thiazide, a2-agonist, direct vasodilatator, ablocker). A secondary cause for the hypertension was excluded. No direct or indirect signs of hemodynamic relevant renal artery stenosis were seen in duplex sonography. End-organ damage was present with the detection of hypertensive cardiomyopathy, retinopathy and nephropathy with micro-albuminuria. Automated blood pressure measurement over the daytime indicated baseline systolic/diastolic BP of 187 ± 16 mmHg/108 ± 8 mmHg (n = 9) before RD; the corresponding heart rate (HR) was 68 ± 7 bpm. For performing RD, access via the right femoral artery with a 6F-sheath was used and fluoroscopic angiography indicated a normal configuration of the left renal artery (Fig. 1a), whereas the right renal artery with high-angle junction from abdominal aorta had a proximal stenosis of approximate 50 % (Fig. 1b). Left artery denervation was performed with the application of five 8-W-radiofrequency ablation points using the standard solid-tip renal denervation catheter (Simplicity catheter; Medtronic/Ardian Inc.). Mean temperature was 59.4 ± 4.5 C with a mean impedance drop of 19.6 ± 1.7 % during the 120 s of ablation at each point. Remarkable intimal oedema and/or vasospasm without compromising the blood flow could be seen after the radiofrequency ablation procedure in the left renal artery (Fig. 1c). Due to right renal artery proximal stenosis, difficulty to advance the ablation catheter into the distal artery (using a ‘RDC guiding catheter’) and the patient’s wish to not further elongate the procedure time, only a left-sided RD approach was chosen. Post-procedural performed controls revealed that the blood pressure could be significantly reduced 2 days after the RD procedure compared to the BP measured before the procedure in the same clinical environment (141 ± 12 mmHg systolic and 85 ± 8 mmHg diastolic; n = 7; P \ 0.001 vs. systolic and diastolic BP before RD); the HR was also reduced (57 ± 4 bpm; n = 3; P = 0.048 vs. HR before RD). Moreover, 1 month after the RD, ambulatory BP measurement revealed a mean systolic blood pressure of 122 ± 17 mmHg and diastolic of 77 ± 20 mmHg at daytime (n = 45; P \ 0.001 vs. systolic and diastolic RR M. R. Schroeter (&) Universitatsmedizin Gottingen, Herzzentrum, Abt. Kardiologie und Pneumologie, Robert-Koch-Str. 40, 37099 Gottingen, Germany e-mail: mschroeter@med.uni-goettingen.de