Quantitative Assessment and Characterization of Microvascular Function Using Diffuse Optical Tomography Version
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 19
- 试验地点
- 1
- 主要终点
- Can diffuse optical tomography detect microvascular function?
研究概览
简要总结
Atherosclerosis is accompanied by microvascular dysfunction (an impairment of blood vessels to dilate or constrict in response to demand). The ability to reliably measure microvascular dysfunction would help identify patients at risk of myocardial infarction and test new treatments. All existing measures of microvascular dysfunction suffer significant limitations.
Near Infrared Spectroscopy (NIRS) is an imaging method that uses an infrared light-source and detector (called optodes) to painlessly shines light into tissue and collect reflected light at different wavelengths. This data allows quantification of the amount of haemoglobin (blood) in the tissue and whether it is oxygenated or de-oxygenated.
Diffuse optical tomography (DOT) is a powerful analysis technique for data collected from multiple NIRH optodes. Unlike most NIRS studies that use a single pair of optodes and collects a single datapoint for each wavelength over time, DOT allows three-dimensional spatial reconstruction of haemodynamic and anatomic changes in a large region of tissue over time.
In preliminary work DOT had the potential to measure forearm reactive hyperaemia, a key indicator of microvascular function. Team will test whether DOT can detect differences between patients and healthy volunteers.
In this work, 30 patients will be recruited with type 2 diabetes, 30 patients who have had a previous myocardial infarction and 30 healthy volunteers. The Investigator will also recruit 50 patients who are on waiting lists for coronary angiography.
The DOT will be used to measure participants' microvascular function after brachial artery occlusion by a blood pressure cuff. The Investigator will then examine whether DOT can detect differences between healthy volunteers, diabetics, and patients with a previous heart attack, and whether DOT is able to predict existence of coronary artery disease on angiography. If successful, DOT can be developed for assessment of microvascular function to the point where it could be applied to clinical studies.
详细描述
Previous pilot studies have shown ability to collect promising data safely. In the following studies, the same study as in the pilot will be performed to apply the array of optodes to the surface of the arm. These emit light painlessly into the tissue and collect scattered light from the tissue. Inflation of a blood pressure cuff around the arm for 5 minutes, then deflate the cuff to allow blood flow back into the tissue. From the data gathered before, during and after the cuff is inflated, 3D reconstructions can be performed of HbO, HbR, and HbT changes in the forearm during and after arterial occlusion.
Study 1) Can DOT detect differences in vascular function between healthy volunteers and patients with proven heart disease or diabetes
This study will measure vascular function in patients with known heart disease (previous myocardial infarction) or diabetes and compare this to matched healthy volunteers. This will establish whether DOT can detect differences in vascular response between these groups. If so, then the method has the potential to be useful diagnostically or prognostically.
Potential participants will be approached by poster, or face to face in STH clinics and provided with the information sheet which participants will be asked to read at home. Participants will be given the opportunity to ask questions by email or telephone at any time afterwards. Participants will be asked to contact us if they are willing to participate.
Participants will be booked with an appointment to attend the Clinical Research Facility at Sheffield Teaching Hospitals (at least 24hrs after receiving the information sheet and having the chance to ask questions) for a visit of 30-45 minutes. Visits will be arranged in advance at a convenient time.
研究设计
- 研究类型
- Interventional
- 分配方式
- Non Randomized
- 干预模型
- Parallel
- 主要目的
- Basic Science
- 盲法
- None
入排标准
- 年龄范围
- 18 Years 至 80 Years（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •Age 18-80 of either sex
- •Ability to read and speak English to a level allowing understanding of the patient information and to give consent to participate
- •Diagnosed as type 2 diabetic for at least 12 months
- •No painful arms or health problems preventing blood pressure cuff inflation
- •No lymphoedema of the arm
- •Not diabetic or known to have suffered a myocardial infarction in the past
排除标准
- •Any patients that do not meet the above criteria will be excluded
研究组 & 干预措施
Vascular function
Diffuse optical tomography detection of differences in vascular function between healthy volunteers and patients with proven heart disease or diabetes.
干预措施: diffuse optical tomography (Device)
Coronary artery disease
Diffuse optical tomography prediction of presence or severity of coronary artery disease on angiography.
干预措施: diffuse optical tomography (Device)
结局指标
主要结局
Can diffuse optical tomography detect microvascular function?
时间窗: 3 years from start date
Measuring microvascular function with diffuse optical tomography
次要结局
- Detecting differences in microvascular function in atherosclerosis(3 years from start date)
- Detecting differences in microvascular function in diabetes(3 years from start date)
- Predicting coronary artery disease before angiography(3 years from start date)