Effects of Controlled Hypercapnic Stimulation on Myocardial Blood Flow Measured With Positron Emission Tomography
试验速览
- 阶段
- 不适用
- 状态
- 终止
- 入组人数
- 20
- 试验地点
- 2
- 主要终点
- Myocardial blood flow differences
研究概览
简要总结
Myocardial perfusion imaging (MPI) is a nuclear scan using a radioisotope to see blood flow to the muscles of the heart when the heart is at rest and when it is under stress. The stress test in MPI can be done using medications, such as persantine, that dilate coronary arteries and increase blood flow. Similarly, elevated carbon dioxide (CO2) levels in the blood, or hypercapnia, also dilates arteries and increases blood flow. Thornhill Research Inc. has developed the RA-MR™ sequential gas delivery system used to control CO2 levels in the blood. The RA-MR™ can deliver precise amounts of CO2 through a mouthpiece for inhalation to increase CO2 levels in the blood and thereby increasing blood flow like during stress.
The objective of this study is to compare the differences in blood flow through the arteries of the heart during stress with hypercapnia and adenosine MPI. The imaging will be done using positron emission tomography (PET) with the radioisotope, or tracer, called Rubidium (Rb-82). The Rb-82 is given through a pump, or elution system.
The investigators hypothesize that hypercapnia will induce a stress-to-rest increase in myocardial blood flow by a factor of 2 or more in myocardial regions supplied by non-stenotic arteries in normal volunteers and participants with coronary artery disease.
研究设计
- 研究类型
- Interventional
- 分配方式
- Na
- 干预模型
- Single Group
- 主要目的
- Diagnostic
- 盲法
- None
入排标准
- 年龄范围
- 18 Years 至 —（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •For all participants
- •Age ≥ 18 years old
- •BMI ≤ 40 kg/m2
- •Able and willing to comply with the study procedures
- •Written informed consent
- •Participants with documented coronary artery disease
- •Stable coronary artery disease on a stable medication regime.
- •Healthy volunteers without known heart disease
- •Low risk of coronary artery disease (CAD)
排除标准
- •History or risk of severe bradycardia (heart rate < 50 beats per minute) not related to chronotropic drugs
- •Known second- or third-degree Atrio-ventricular block without pacemaker
- •Atrial flutter or atrial fibrillation
- •Dyspnea (NYHA III/IV), wheezing asthma or Chronic Obstructive Pulmonary Disease (COPD)
- •Coronary artery bypass graft (CABG) surgery within 60 days prior to screening or at any time after consent
- •Percutaneous coronary intervention (PCI) within 30 days prior to screening or at any time following consent
- •Acute myocardial infarction or acute coronary syndrome within 60 days prior to screening or at any time following consent
- •Recent use of dipyridamole, dipyridamole-containing medications (e.g. Aggrenox)
- •Known hypersensitivity to adenosine
- •Breastfeeding or pregnancy
- •Claustrophobia or inability to lie still in a supine position
- •Unwillingness or inability to provide informed consent
结局指标
主要结局
Myocardial blood flow differences
时间窗: Difference between baseline rest scan blood flow and hypercapnia stress scan myocardial blood flow at 50 mmHg, 55 mmHg, 60 mmHg levels from baseline. Imaging and intervention analysis will be complete in 4 years.
The myocardial blood flow (MBF) will be quantified with each Rb-82 PET scan done. Polar-maps representing MBF are generated for each rest and stress state using in-house FlowQuant©software. The rest scan will be the baseline. The myocardial blood flow in the four stress scans using hypercapnia as a stress agent will be compared to the rest baseline myocardial blood flow and the adenosine stress scan myocardial blood flow.
次要结局
- Difference bewteen absolute myocardial blood flow with hypercapnia and with adenosine stress.(Quantification and comparison of the differences in myocardial blood flow with adenosine stress and increasing levels of CO2 as a stress agent. Imaging and intervention analysis will be complete in 4 years.)
- Absolute myocardial blood flow differences between end-tidal CO2 scans(Difference between baseline and 60 mmHg PetCO2. Imaging and intervention analysis will be complete in 4 years.)
研究者
Terrence Ruddy
MD
Ottawa Heart Institute Research Corporation