Effects of Ranolazine on Coronary Flow Reserve in Symptomatic Patients With Diabetes and Suspected or Known Coronary Artery Disease
试验速览
- 阶段
- 3 期
- 状态
- 已完成
- 入组人数
- 47
- 试验地点
- 1
- 主要终点
- Change in Post-exercise Coronary Vasodilator Reserve
研究概览
简要总结
Coronary vascular dysfunction is highly prevalent among patients with known or suspected Coronary Artery Disease (CAD)1, increases the severity of inducible myocardial ischemia (beyond the effects of upstream coronary obstruction)2, and identifies patients at high risk for serious adverse events, including cardiac death1, 3-5. Diabetic patients without known CAD with impaired coronary vascular function show a risk of cardiac death comparable to, and possibly higher, than that for non-diabetic patients with known CAD10. In the setting of increased oxygen demand, coronary vasodilator dysfunction can upset the supply-demand relationship and lead to myocardial ischemia, subclinical left ventricular dysfunction (diastolic and systolic), and symptoms.
The significance of microvascular coronary dysfunction is increasingly recognized as invasive and non-invasive (PET) methods of quantifying CFR become available.
Importantly, current treatment strategies for obstructive CAD, such as percutaneous coronary intervention with angioplasty and stenting, are not helpful in microvascular disease. Similarly, mortality-altering treatments for systolic heart failure, such as angiotensin converting enzyme inhibitors, have not been beneficial in treating diastolic dysfunction.
详细描述
Ranolazine is a novel anti-anginal agent which inhibits the late sodium current in cardiomyocytes, decreasing sodium and calcium overload. In ischemia, excess of intracellular calcium may impair myocyte relaxation and contribute to ventricular diastolic stiffness, which in turn affects myocardial contractility and perfusion. Ranolazine is FDA-approved for treatment of chronic angina. In three randomized, placebo-controlled trials of patients with stable angina, it was shown to increase exercise time free of angina and ST-segment depression, increase exercise capacity and decrease angina when used in combination with established antianginal agents including diltiazem, amlodipine or atenolol, and reduce the frequency of angina on patients on maximum doses of amlodipine.Similarly, in a large population of patients with acute coronary syndromes, ranolazine also decreased exertional angina symptoms and incidence of arrhythmias, with no effect on mortality. Interestingly, in this same study, it significantly improved hemoglobin A1c and recurrent ischemia in patients with diabetes mellitus, and reduced the incidence of increased hemoglobin A1c in patients without known prior hyperglycemia.
Although the anti-ischemic effect of ranolazine is thought to be mediated in part by increased myocardial blood flow,there is currently limited evidence for such an effect on tissue perfusion. A previous study in women without overt CAD did not detect improved myocardial blood flow after treatment with ranolazine. In that study, however, coronary hyperemia was elicited with adenosine (which uncouples blood flow from cardiac work, and reflects predominantly endothelial-independent vasodilation) rather than exercise, which triggers a more complex interplay between metabolic demand, coronary hemodynamics, and vasodilator response. Thus, there is a need for additional investigation of whether the beneficial effects of ranolazine on exertional symptoms are directly related to improved global tissue perfusion. Such evidence would support the use of ranolazine as an anti-ischemic therapy in the challenging population of symptomatic patients with evidence of microvascular dysfunction without obstructive CAD.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Crossover
- 主要目的
- Other
- 盲法
- Double (Participant, Investigator)
入排标准
- 年龄范围
- 18 Years 至 90 Years（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 否
入选标准
- 未提供
排除标准
- 未提供
研究组 & 干预措施
Ranolazine
Subject will receive labeled bottles containing tablets with ranolazine 500 mg or a matching placebo provided by the sponsor. Each patient will receive both ranolazine and placebo for 4 weeks, but both the investigator and subject are blinded to the order.
干预措施: Ranolazine (Drug)
Placebo
Subject will receive labeled bottles containing tablets with ranolazine 500 mg or a matching placebo provided by the sponsor. Each patient will receive both ranolazine and placebo for 4 weeks, but both the investigator and subject are blinded to the order.
干预措施: Placebo (Drug)
结局指标
主要结局
Change in Post-exercise Coronary Vasodilator Reserve
时间窗: 4 weeks
Change (from baseline) in post-exercise coronary vasodilator reserve, as measured by PET imaging at 4 weeks post randomization. Per-patient global coronary flow reserve (CFR) was calculated as the ratio of absolute MBF at stress over rest for the entire left ventricle. Quantitation of MBF was performed by two operators blinded to patient, treatment period and treatment order.
次要结局
- Change in LV Diastolic Function(4 weeks)
研究者
Marcelo F. Di Carli, MD, FACC
Chief, Nuclear Medicine
Brigham and Women's Hospital