Effects of an ARB on microcirculation in essential hypertension
| ISRCTN | ISRCTN62554526 |
|---|---|
| DOI | https://doi.org/10.1186/ISRCTN62554526 |
| Clinical Trials Information System (CTIS) | 2008-005432-32 |
| Protocol serial number | 6830 |
| Sponsor | St George's, University of London (UK) |
| Funder | Takeda UK Limited (UK) |
- Submission date
- 12/05/2010
- Registration date
- 12/05/2010
- Last edited
- 24/01/2019
- Recruitment status
- No longer recruiting
- Overall study status
- Completed
- Condition category
- Circulatory System
Prospectively registered
Protocol
Statistical analysis plan
Results
Individual participant data
Plain English summary of protocol
Not provided at time of registration
Contact information
Dr Tarek F Antonios
Scientific
Scientific
Blood Presure Unit
St George's University
Cranmer Terrace
London
SW17 0RE
United Kingdom
Study information
| Primary study design | Interventional |
|---|---|
| Study design | Single centre randomised interventional treatment trial |
| Secondary study design | Randomised controlled trial |
| Study type | Participant information sheet |
| Scientific title | Effects of an angiotensin receptor antagonist candesartan versus a calcium channel blocker amlodipine on microvascular rarefaction, endothelial dysfunction, and microalbuminuria in essential hypertension |
| Study acronym | CAMIRA |
| Study objectives | Many abnormalities are known to occur in the microcirculation in essential hypertension including reduction in vascular density or rarefaction. Capillary rarefaction is not confined to the skin but represents a widespread phenomenon affecting several tissues in hypertensive individuals including the myocardium, the kidneys and the brain resulting in reducing coronary blood flow reserve, and precipitating heart failure in cardiac hypertrophy. In this study we aim to investigate, in a double-blind randomised design, the effects of treating hypertension with an angiotensin receptor blocker versus a calcium antagonist on the reversibility of capillary rarefaction. On 19/11/2013 the anticipated end date was changed from 01/10/2011 to 01/10/2014. |
| Ethics approval(s) | London-Surrey Borders Research Ethics Committee, 19/11/2008, ref: 08/H0806/72 |
| Health condition(s) or problem(s) studied | Topic: Cardiovascular; Subtopic: Cardiovascular (all Subtopics); Disease: Cardiovascular |
| Intervention | After a 2-week single-blind placebo run-in period, patients will be randomised to 8 weeks treatment with either candesartan 8 mg once daily orally (with forced titration to 16 mg once daily orally after 2 weeks) or amlodpine 5 mg once daily orally (with forced titration to 10 mg once daily orally after 2 wks). Study entry: single randomisation only |
| Intervention type | Drug |
| Phase | Phase IV |
| Drug / device / biological / vaccine name(s) | Candesartan, amlodipine |
| Primary outcome measure(s) |
The increase in maximal capillary density at the end of 8 weeks treatment. |
| Key secondary outcome measure(s) |
1. Change in aortic augmentation index at 8 weeks |
| Completion date | 01/10/2014 |
Eligibility
| Participant type(s) | Patient |
|---|---|
| Age group | Adult |
| Lower age limit | 18 Years |
| Sex | All |
| Target sample size at registration | 46 |
| Key inclusion criteria | 1. Male and female, aged 18 years or older 2. Uncomplicated mild-to-moderate essential hypertension, i.e., sitting diastolic blood pressure (BP) greater than or equal to 90 to less than 110 mmHg and/or systolic BP greater than or equal to 140 to less than 180 mmHg) 3. Not previously treated for their high blood pressure 4. Caucasian and light-coloured Asians only, this is due to the technical difficulty of performing capillaroscopy in dark-skinned individuals |
| Key exclusion criteria | 1. Malignant or accelerated hypertension 2. Serum creatinine greater than 180 µmol/L 3. Ischaemic heart disease 4. Cerebrovascular disease 5. Impaired liver functions 6. Diabetes mellitus 7. Pregnancy or risk of pregnancy 8. Lactation 9. History of alcoholism, drug abuse or other problems that are likely to invalidate the informed consent 10. Dark-skinned individuals (capillary microscopy can't be performed) |
| Date of first enrolment | 01/02/2010 |
| Date of final enrolment | 01/10/2014 |
Locations
Countries of recruitment
- United Kingdom
- England
Study participating centre
Blood Presure Unit
Blood Presure Unit
St George's University
Cranmer Terrace
London
SW17 0RE
United Kingdom
St George's University
Cranmer Terrace
London
SW17 0RE
United Kingdom
Results and Publications
| Individual participant data (IPD) Intention to share | No |
|---|---|
| IPD sharing plan summary | Not provided at time of registration |
| IPD sharing plan |
Study outputs
| Output type | Details | Date created | Date added | Peer reviewed? | Patient-facing? |
|---|---|---|---|---|---|
| Results article | results | 14/11/2017 | 24/01/2019 | Yes | No |
| HRA research summary | 28/06/2023 | No | No | ||
| Participant information sheet | Participant information sheet | 11/11/2025 | 11/11/2025 | No | Yes |
Editorial Notes
24/01/2019: Publication reference added
20/01/2017: No publications found in PubMed, verifying study status with principal investigator.
