Effects of Renal Sympathetic Denervation on Blood Pressure, Sleep Apnea Course, and Glycemic Control in Patients With Resistant Hypertension and Sleep Apnea

Abstract

Abstract-Percutaneous renal sympathetic denervation by radiofrequency energy has been reported to reduce blood pressure (BP) by the reduction of renal sympathetic efferent and afferent signaling. We evaluated the effects of this procedure on BP and sleep apnea severity in patients with resistant hypertension and sleep apnea. We studied 10 patients with refractory hypertension and sleep apnea (7 men and 3 women; median age: 49.5 years) who underwent renal denervation and completed 3-month and 6-month follow-up evaluations, including polysomnography and selected blood chemistries, and BP measurements. Antihypertensive regimens were not changed during the 6 months of follow-up. Three and 6 months after the denervation, decreases in office systolic and diastolic BPs were observed (median: Ϫ34/Ϫ13 mm Hg for systolic and diastolic BPs at 6 months; both PϽ0.01). Significant decreases were also observed in plasma glucose concentration 2 hours after glucose administration (median: 7.0 versus 6.4 mmol/L; Pϭ0.05) and in hemoglobin A1C level (median: 6.1% versus 5.6%; PϽ0.05) at 6 months, as well as a decrease in apnea-hypopnea index at 6 months after renal denervation (median: 16.3 versus 4.5 events per hour; Pϭ0.059). In conclusion, catheter-based renal sympathetic denervation lowered BP in patients with refractory hypertension and obstructive sleep apnea, which was accompanied by improvement of sleep apnea severity. Interestingly, there are also accompanying improvements in glucose tolerance. Renal sympathetic denervation may conceivably be a potentially useful option for patients with comorbid refractory hypertension, glucose intolerance, and obstructive sleep apnea, although further studies are needed to confirm these proof-of-concept data. (Hypertension. 2011;58:559-565.)

Proceedings from the Society of Interventional Radiology Foundation Research Consensus Panel on Renal Sympathetic Denervation

“…Subgroup analysis and phase II testing have also shown improvements in other diseases associated with autonomic dysfunction, such as sleep apnea, insulin-resistant diabetes, left ventricular (LV) hypertrophy, tachyarrhythmias, and congestive heart failure (CHF) (13,16). Ongoing RDN clinical trials for the treatment of resistant HTN continue this trend of investigating other potential benefits associated with RDN.…”

“…Witkowski et al (16) showed that OSA was a consequence as well as a cause of increased sympathetic activity in patients who underwent RDN for resistant HTN. These investigators also reported that the apneahypopnea index improved in 8 of 10 patients 6 months after RDN.…”

“…Denervation can also increase venous compliance, leading to increased capacity, which may alleviate the blood pooling in the peripharyngeal tissues. Better BP control can also contribute to apnea improvement through its influence on baroreflex reactivity and central respiratory control (13,16). RDN in patients with resistant HTN and OSA might attenuate the effects of activation of the sympathetic nerves.…”

“…Additional findings from mostly small, uncontrolled, observational studies have suggested numerous favorable cardiovascular responses to RDN that are in need of corroboration (11)(12)(13)(14)(15)(16). The potential for early clinical adoption has also driven the development and clinical testing of multiple new devices for ablation of the perirenal sympathetic nerve fibers (17,18).…”

Intrathoracic pressure oscillations during obstructive apneas disturb ventricular repolarisation

“…These findings emphasize the importance of autonomic imbalance in OSA-associated AF. Also, renal sympathetic denervation (RDN) has also been shown to reduce OSA-severity in hypertensive patients as well as blood pressure (Witkowski et al 2011).…”