Clinical Efficacy of Permanent Internal Mammary Artery Occlusion in Stable Coronary Artery Disease
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 100
- 试验地点
- 1
- 主要终点
- Treadmill exercise time increment
研究概览
简要总结
Cardiovascular diseases remain the number one cause of death globally, primarily consequence of myocardial infarction. Although widely used in stable coronary artery disease (CAD), percutaneous coronary intervention (PCI) has not been shown to reduce the incidence of myocardial infarction or death. In contrast, coronary artery bypass grafting (CABG) significantly reduces rates of death and myocardial infarction compared to PCI, but at a higher rate of stroke. Similarly, 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.
While a multitude of interventions has been shown to be effective in collateral growth promotion, so far, the effect of current interventions is only temporary, and therefore, repeated application is necessary to sustain the level of collaterals. 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.
Coronary functional changes observed in response to permanent distal IMA occlusion have so far, not been related to clinical outcome parameters. Therefore, a controlled, randomized, double-blind comparison of clinical efficacy between a group of patients receiving permanent IMA occlusion vs. a sham-procedure will be consequently performed. Since single antianginal agents have been demonstrated to increase exercise time in comparison to placebo, an improvement of the physical performance due to the increased blood flow by the permanent distal IMA occlusion is expected.
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
- Treatment
- 盲法
- Double (Participant, Outcomes Assessor)
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
- •Chronic stable 1- to 3-vessel CAD
- •Written informed consent to participate in the study
排除标准
- •Absence of at least one coronary stenotic lesion ≥50% diameter narrowing.
- •Acute coronary syndrome; unstable cardiopulmonary condition, unstable angina pectoris
- •Severe valvular heart disease
- •Congestive heart failure NYHA III-IV
- •Prior coronary artery bypass surgery / prior cardiac surgery
- •CAD best treated by coronary artery bypass grafting
- •Prior Q-wave myocardial infarction in the vascular territory undergoing collateral function measurement
- •Severe renal or hepatic failure
- •Women of childbearing age
结局指标
主要结局
Treadmill exercise time increment
时间窗: Follow-up (week 6)
Treadmill exercise time at follow-up minus treadmill exercise time at baseline exam (difference measured in seconds)
次要结局
- Angina pectoris(Follow-up (week 6))
- Occlusive intracoronary ECG ST-segment shift(Follow-up (week 6))
- Seattle Angina Questionnaire scores(Follow-up (week 6))
- Time to 0.1mV ECG ST-segment depression(Follow-up (week 6))
- Fractional flow reserve(Follow-up (week 6))
- Collateral flow index(Follow-up (week 6))