Comparing the role of the carotid body in human heart failure

Not Applicable

Suspended

• Conditions: Heart failure; Circulatory System

• Registration Number: ISRCTN14684459
• Lead Sponsor: niversity of Bristol

Brief Summary

Not available

Detailed Description

Not available

Study Timeline

• Results First Posted: 1900-01-01
• Study Start: 2019-05-02
• Last Update Posted: 4 May 2020
• Study Completion: 2021-04-30

Recruitment & Eligibility

• Status: Suspended
• Sex: All
• Target Recruitment: 55

Inclusion Criteria

All participants:
1. Aged 18-90 years

HFrEF participants:
As per the European Society of Cardiology (ESC) guidelines:
1. Signs and symptoms of heart failure AND
2. Raised natriuretic peptides AND
3. Evidence of reduced ejection fraction (EF < 40%)

HFpEF participants:
As per the European Society of Cardiology (ESC) guidelines:
1. Signs and symptoms of heart failure AND
2. Raised natriuretic peptides (e.g. NTproBNP) AND
3. Evidence of preserved ejection fraction (EF > 50%) AND
4. Objective evidence of cardiac functional and structural alterations

Exclusion Criteria

All participants:
1. Requirement for oxygen therapy to maintain oxygen saturation
2. Oxygen saturations at rest < 92%
3. Chronic obstructive pulmonary disease (COPD) and known structural lung disease
4. Current smoker (within the last 2 months)
5. Acute coronary syndrome, coronary revascularisation or unstable angina in last 6 months
6. HF related hospitalisation in the last 1 month.
7. Transient ischaemic attack or stroke in the last 6 months
8. Surgery under general anaesthesia in the last 3 months
9. Change in regular medications within the last 1 month
10. Clinically significant neurological disorder, including peripheral neuropathy
11. Type 1 Diabetes Mellitus
12. Heart transplant
13. Haemodialysis or peritoneal dialysis
14. Pregnancy, breast feeding or recent unprotected intercourse
15. Palliative care/chemotherapy
16. Recreational drug use and/or intravenous drug use
17. Alcohol intake > 28 units/week
18. Febrile illness/clinically significant infection within two weeks of participation
19. Contraindications to dopamine administration:
19.1. Known phaeochromocytoma
19.2. Known hyperthyroidism
19.3. Known uncontrolled atrial or ventricular tachyarrhythmias
19.4. Known hypersensitivity to dopamine or any of the excipients
19.5. Participants on the following medications:
19.5.1. Monoamine oxidase I inhibitors
19.5.2. Phenytoin
19.5.3. Ergot alkaloids
19.5.4. Tricyclic antidepressants
19.5.5. Guanethidine

Healthy controls:
1. No history of hypertension

Study & Design

• Study Type: Observational
• Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
<br> 1. CB chemosensitivity and tonicity and levels of sympathetic activity in HFrEF & HFpEF patients compared to healthy controls at rest:<br> 1.1. Hypoxic ventilatory response (HVR) in litre/minute/%SpO2<br> 1.2. Change in minute ventilation during dopamine infusion (l/min)<br> 1.3. Muscle sympathetic nerve activity (burst frequency, usually quantified as bursts per 100 heartbeats) at baseline<br> 2. Change in exercise tolerance and perceived rate of exertion in HFpEF patients as a result of dopamine administration vs saline during VO2 Peak Test:<br> 2.1. BORG score at peak<br> 2.2. VO2 peak measurement, overall VE/VCO2 slope<br>

Secondary Outcome Measures

Name	Time	Method
<br> Differences between healthy controls, HFrEF & HFpEF groups at rest during carotid body chemosensitivity testing:<br> 1. BP responses to hypoxia<br> 2. BP response to dopamine and hypoxia (small subset of participants)<br> 3. HR responses to hypoxia<br> 4. HR responses to dopamine and hypoxia (small subset of participants)<br> 5. Inflammatory markers<br> 6. Pulse Wave Analysis<br>