Effect of Permanent Internal Mammary Artery Occlusion on Extracardiac Coronary Collateral Supply: a Randomized Controlled Study
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 100
- 试验地点
- 2
- 主要终点
- Change from baseline in right coronary Collateral Flow Index (CFI)
研究概览
简要总结
Coronary artery disease and the benefit of bypasses:
Despite considerable advances in medicine, cardiovascular diseases remain the number one cause of death globally, primarily consequence of myocardial infarction (MI). Coronary collaterals exert a protective effect by providing an alternative source of blood flow to a myocardial territory potentially affected by an acute coronary occlusion. Coronary collaterals represent pre-existing inter-arterial anastomoses and as such are the natural counter-part of surgically created bypasses. Sufficient coronary collaterals have been shown to confer a significant benefit in terms of overall mortality and cardiovascular events. In this regard, the concept of augmenting coronary collateral function as an alternative treatment strategy to alter the course of CAD, as well as to control symptoms, is attractive.
Durable promotion of coronary collateral circulation:
Before the advent of coronary artery bypass grafting, permanent augmentation of coronary collateral supply by a single structural modification has already been attempted. Bilateral ligation of the internal mammary arteries (IMA) was performed in CAD patients to alleviate angina pectoris and electrocardiographic (ECG) signs of ischemia. The prevalent in vivo function of natural internal mammary arteries (IMA)-to-coronary artery bypasses and their anti-ischemic effect has been recently demonstrated by the investigators' research group. Levels of collateral function and myocardial ischemia were determined in a prospective, open-label clinical trial of permanent IMA device occlusion. In this study, coronary collateral function, has been shown to be augmented in the presence vs the absence of distal permanent ipsilateral IMA occlusion. These findings have been corroborated by the observed reduction in ischemia in the intracoronary ECG.
After this first step, the concept of permanent right IMA occlusion will be now investigated with a randomized, sham-controlled clinical trial.
详细描述
Despite considerable advances in medicine, cardiovascular diseases remain the number one cause of death globally. In industrialized countries, coronary artery disease (CAD) is the leading cause of death, consequence of myocardial infarction (MI).
In patients with acute coronary syndrome, percutaneous coronary intervention (PCI) has been shown to improve outcomes. For chronic stable CAD, a recent meta-analysis including more than 93'000 patients has concluded that there may be "evidence for improved survival with new generation drug eluting stents but no other percutaneous revascularization technology compared with medical treatment" . Conversely, a current review of recently published meta-analyses and the detailed analyses of 3 widely quoted individual studies indicate no difference exists among stable CAD patients between PCI and medical therapy regarding nonfatal myocardial infarct or all-cause or cardiovascular mortality. A very recently published randomized controlled trial among patients with stable, single-vessel CAD, the so called ORBITA trial, has found that PCI of the stenotic lesion did not prolong exercise time by more than the effect of a sham procedure during the short observation period of 6 weeks.
In contrast, coronary artery bypass grafting (CABG) was superior to PCI in patients with diabetes and multivessel CAD. CABG significantly reduced rates of death and myocardial infarction compared to PCI, but at a higher rate of stroke. Furthermore, in patients with advanced CAD, rates of myocardial infarction were more than 60% lower with CABG compared to PCI.
Conceptually, the benefit of CABG over PCI is not surprising as PCI targets significant coronary lesions thought to be responsible for causing ischemia. However, the deleterious effects of atherosclerosis are not typically preceded by significant luminal vascular narrowing. The vulnerable plaque eventually becoming the culprit plaque (causing myocardial infarction or sudden cardiac death) has typically a relatively mild stenosis. Furthermore, due to being multifocal and widespread, plaque vulnerability is not a target for, nor amenable to PCI.
Conversely, artificial - or natural - bypasses exert a protective effect by providing an alternative source of blood flow to a myocardial territory potentially affected by an acute coronary occlusion. Coronary collaterals represent pre-existing inter-arterial anastomoses and as such are the natural counter-part of surgically created bypasses. Sufficient coronary collaterals have been shown to confer a significant benefit in terms of overall mortality and cardiovascular events.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Parallel
- 主要目的
- Basic Science
- 盲法
- Single (Participant)
入排标准
- 年龄范围
- 18 Years 至 —（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 否
入选标准
- •Age > 18 years
- •Referred for elective coronary angiography
- •Written informed consent to participate in the study
- •Significant stenosis of right coronary artery (FFR ≤0.80)
排除标准
- •Acute coronary syndrome; unstable cardiopulmonary conditions, unstable angina pectoris
- •Collateral flow index of right IMA <0.25
- •Severe cardiac valve disease
- •Congestive heart failure NYHA III-IV
- •Prior coronary artery bypass surgery / prior cardiac surgery
- •Coronary artery disease best treated by coronary artery bypass grafting
- •Coronary artery disease unsuitable for intracoronary pressure measurements
- •Prior Q-wave myocardial infarction in the vascular territory undergoing collateral function determination
- •Severe renal or hepatic failure
- •Women of childbearing age
研究组 & 干预措施
Interventional Study Arm
In the presence of a significant right coronary artery stenosis and randomization to the intervention group, catheter-based occlusion of the right IMA distal to the take-off of the pericardio-phrenic branch is performed at baseline using a dedicated occlusion device (Amplatzer vascular plug, CE0086).
干预措施: Amplatzer vascular plug (Device)
Sham-Control
In the presence of a significant right coronary artery stenosis, and randomization to the sham-procedure: right IMA will be selectively intubated using an appropriate catheter. Angiography of the RIMA and the pericardiacophrenic branch will be performed.
干预措施: Sham Controll (Other)
结局指标
主要结局
Change from baseline in right coronary Collateral Flow Index (CFI)
时间窗: Follow-up (week 6)
Change from baseline in right coronary Collateral Flow Index (CFI) at follow-up (week 6) vs baseline
次要结局
- Angina pectoris(Follow-up (week 6))
- Change from baseline in intracoronary and surface ECG ST-segment shift during temporary right and left coronary balloon occlusion(Follow-up (week 6))
- Fractional Flow Reserve(Follow-up (week 6))
- Number of patients with angiographic visibility of right IMA-to-coronary anastomoses(Follow-up (week 6))