The Iliac Arterio-venous Fistula for Treatment of Neurally Mediated Syncope Study

Study Overview
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Brief Summary
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The purpose of the study is to investigate the efficacy of the ROX coupler in treating patients with tilt test proven Neurally mediated syncope.

Detailed Description
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Neurally mediated syncope (NMS) is a debilitating condition, with no proven therapeutic measures. The ROX coupler is a device used to create an Iliac arterio-venous anastamosis which allows a shunt of 0.8 litres per minute. The haemodynamic changes following creation of an arterio-venous anastomosis at the iliac level leads to an increase in cardiac preload, reversing finding thought to induce NMS. This a randomised controlled study to evaluate the effect of Iliac arterio-venous anastamosis in patients with neurally mediated syncope. The Head up tilt test is used as an objective measure to evaluate the effect of the arterio-venous anastamosis in patients with NMS. Participants with tilt test proven NMS will be eligible for the study ( if they satisfy all other eligibility criteria). Participants will be randomised to ROX coupler intervention or standard therapy. The primary outcome measure will be absence of loss consciousness on tilt table testing at 3 months post intervention.

Official Title
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The Iliac Arterio-venous Fistula for Treatment of Neurally Mediated Syncope Study

Conditions
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Neurally Mediated Syncope

Intervention / Treatment
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* Device: ROX COUPLER
* Procedure: Right heart catheterisation and routine care


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Absence of transient loss of consciousness associated with reflex bradycardia or hypotension on tilt testing at 3 months following randomised intervention Exclusion Criteria: Time to first episode of syncope after randomised intervention Number of syncopal episodes in the first 3 months after randomised intervention. Tilt table response at 6 months following randomised intervention i.e. 3 months after unblinding Number of syncopal episodes at 6 months after intervention i.e. 3 months after unblinding
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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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: ROX COUPLER<br>Iliac arterio-venous anastamosis created by insertion of ROX coupler device. | Device: ROX COUPLER<br>* ROX coupler device is inserted to create an Iliacartero-venous anastamosis following right heart catheterisation.<br>|
| Sham Comparator: ROUTINE CARE<br>Right heart catheterisation and Routine care of Neurally mediated syncope. | Procedure: Right heart catheterisation and routine care<br>* Participants will have right heart catheterisation followed by routine care. Participants will be blinded to ROX coupler insertion.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Absence of loss of consciousness on tilt table testing | Absence of loss of consciousness associated with reflex bradycardia or hypotension on head up tilt table testing at 3 months post intervention | 3 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Time to first episode of syncope after randomised intervention |  | 3 months | 
| Number of syncopal episodes in the first 3 months after randomised intervention |  | 3 months | 
| Tilt table response at 6 months following randomised intervention i.e. 3 months after unblinding |  | 6 months | 
| Number of syncopal episodes at 6 months after intervention i.e. 3 months after unblinding |  | 6 months |