Effect of Catheter-based Radiofrequency Ablation Therapy in Patient With Therapy-resistant Hypertension and Sleep Apnea Syndrome

Study Overview
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Brief Summary
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The aim of this prospective single-center study is to evaluate sympathetic nervous system directly measured by microneurography, 24-hour blood pressure, endothelial function, vascular compliance, quality of life and platelet adhesion in patients with sleep apnea syndrome (defined by a complaint of excessive daytime sleepiness, an Epworth sleepiness score>8[10], and an apnea/hypopnea index (AHI>15/h) before and after catheter-based radiofrequency ablation of renal nerve. If the selected patients are treated with CPAP, this therapy should be stable during the whole study time. Primary and secondary end-point will be measured before and 1, 3, 6 and 12 months after renal sympathetic denervation.

Official Title
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Effect of Catheter-based Radiofrequency Ablation Therapy of the Renal Sympathetic-Nerve System for Patient With Sleep Apnea Syndrome and Therapy Resistant Hypertension

Conditions
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Therapy-resistant Hypertension and Sleep Apnea

Intervention / Treatment
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* Other: No intervention will be done. The study is observational


Participation Criteria
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Eligibility Criteria
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Inclusion criteria: We plan to include male or female subjects, age 18-80 with a diagnosis of medium-severe sleep apnea syndrome (defined by symptoms, a complaint of excessive daytime sleepiness, an Epworth sleepiness score >8, and an apnea / hypopnea index >15/h) and a resistant hypertension (systolic blood pressure >140 mmHg or >130 mmHg in patients with type II diabetes or chronic kidney disease, under treatment with three antihypertensive drugs including a diuretic). If the selected patients are treated with CPAP, this therapy should be stable during the whole study time. Every patient will be asked for a written informed consent. Exclusion criteria: - Heart failure (normal ejection fractions on echocardiography and no clinical signs and symptoms of heart failure). Long acting nitrates, or PDE-5-Hemmer Alcohol or drug abuse, Malignancy (unless healed or remission > 5 years) Disease with systemic inflammation (e.g. rheumatoid arthritis, M. Crohn) Pulmonary Hypertension (PAP>50 mmHg) Pregnancy Anatomical contraindication to renal denervation Know allergy to contrast Participation in another study within the last month

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 80 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Intervention/Treatment |
| --- |
|Other: No intervention will be done. The study is observational|nan|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in sympathetic nervous system activity (burst/min and burst/100 HB) before and after catheter-based radiofrequency ablation | The primary objective of this study is to evaluate sympathetic nervous system activity in patients with sleep apnea syndrome before and 6 and 12 months after catheter-based radiofrequency ablation therapy of the renal sympathetic-nerve system | 6 and 12 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in 24-hour blood pressure (24 hour, day and night mean) before and after catheter-based renal denervation | Change in 24-hour blood pressure (24 hour, day and night mean) before and after catheter-based renal denervation | 1, 3, 6 12 months | 
| Change in renal function (creatinin plasma level and GFR CKD-EPI Formula) before and after catheter-based renal denervation | Change in creatinin plasma level and GFR CKD-EPI Formula before and after catheter-based renal denervation | 1, 3, 6, 12 | 
| Change in sleep quality, pulse-oximetry, AHI, quality of life and subjective sleepiness with the Epworth sleepiness score before after catheter-based renal denervation |  | 1, 3, 6 and 12 months | 
| Change in 24-hour Holter and heart rate variability, echocardiogramm before and after catheter-based renal denervation |  | 6 and 12 months | 
| Change in vascular function and oxidative stress and inflammation parameters before and after catheter-based renal denervation | Change in vascular function (endothelial function as flow mediated dilatation, arterial stiffness by pulse wave velocity) and oxidative stress and inflammation parameters before and after catheter-based renal denervation | 1, 3, 6, and 12 months |