Kidney Transplantation and Renal and Myocardial Perfusion
试验速览
- 阶段
- 不适用
- 入组人数
- 60
- 主要终点
- cardiac flow reserve of kidney transplant patients
研究概览
简要总结
The cardiovascular morbidity and mortality is significantly higher in chronic kidney disease (CKD) patients, especially in dialysis patients, than in normal population. The increased risk of cardiovascular diseases is multifactorial.Endothelial dysfunction is one of the explanations for the poor outcome of kidney patients. The kidney transplantation seems to halt the progression of the cardiovascular morbidity.
Coronary flow reserve (CFR), the capacity of coronary vessels to dilate in response to vasoactive agent, is a marker of the endothelial dysfunction. It is reduced in renal impairment as well as in many preatherosclerotic states and coronary heart disease. The method of choice to evaluate CRF is positron emission tomography (PET). In kidney transplant patients CFR seems to be worse than in healthy controls but better than in dialysis patients. However, the evidence is scarce.
Renal flow reserve (RFR) is smaller than that of heart. RFR probably reflects endothelial function in the same way as CFR does. Declining RFR could perhaps be used to anticipate worsening kidney function especially in kidney transplant patients and be in favour for transplant biopsy.There are no studies of RFR in renal allograft patients.
The objectives of this study are to examine the effect of kidney transplantation on coronary flow reserve (CFR), the change of renal flow reserve (RFR) in kidney transplant patients during the first year after transplantation and assess the correlation between the change of renal blood flow / RFR and kidney biopsy findings in kidney transplant patients.
The first hypothesis of this study is that coronary flow reserve of transplant patients is better than that of dialysis patients but worse than that of healthy controls. The second hypothesis is that renal transplant perfusion reserve is better at one year than at three months after transplantation. The third hypothesis is that pathologic kidney biopsy findings correlate negatively with renal perfusion reserve.
详细描述
INTRODUCTION Cardiovascular morbidity and kidney impairment Patients with chronic kidney disease (CKD) have a high risk of cardiovascular events and that is already substantial in early stages of CKD. The pathophysiology of cardiovascular disease in CKD patients is poorly understood. In end stage renal disease sudden arrhythmic cardiac death rather than myocardial infarction due to atherosclerosis is the predominant cause of cardiovascular mortality. In uremia endothelial vasodilation is impaired. This may be one explanation for the high prevalence of cardiovascular disease in CKD.The renal transplantation reduces cardiovascular risk and improves the patient survival.
The traditional approaches for cardiac risk assessment like SPECT-MPI (single photon emission computed tomography-myocardial perfusion imaging) are perhaps not as liable in chronic kidney disease patients than in healthy population. Coronary angiography is invasive and may induce contrast nephropathy and deteriorating kidney function.
The coronary flow reserve (CFR) or myocardial flow reserve (MFR) is the magnitude of increase in coronary flow which is calculated assessing myocardial blood flow at rest (basal flow) and during pharmacological vasodilation and hyperemia.Myocardial blood flow (MBF) needs to dynamically adapt to the metabolic demand of the myocardium and it is controlled by coronary microvascular resistance. Microvascular dysfunction may be caused by different mechanisms, one of them is microvascular dysfunction.
CFR has been measured by transthoracic echocardiography(TTEC) as well as intracoronary Doppler echocardiography has been used to estimate CFR. However, blood velocity measurement in one coronary artery is not the same as quantification of myocardial blood flow.Magnetic resonance imaging (MRI) can be used to quantify myocardial blood flow as well but it is not safe in renal impairment because of the contrast agent gadolinium. In recent years PET has shown to be the modality of choice to measure myocardial blood flow (MBF). It is noninvasive and it is safe in renal impairment.
High prevalence of cardiovascular morbidity in CKD-patients is not only explained by large vessel atherosclerosis. It has been shown poor cardiac outcome in CKD-patients without obstructive coronary artery disease. The dysfunction of microvasculature may be one explanation in such circumstances.
研究设计
- 研究类型
- Interventional
- 分配方式
- Non Randomized
- 干预模型
- Parallel
- 主要目的
- Diagnostic
- 盲法
- None
入排标准
- 年龄范围
- 18 Years 至 85 Years（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •dialysis patients who are on the kidney waiting list
排除标准
- •diabetes, hypertension, coronary artery disease, cerebrovascular disease, universal atherosclerosis
- •In the retrospective part of the study, inclusion criteria:
- •kidney transplant is 3+/-1years old
- •GFR >30 ml/min Exclusion criteria
- •manifest coronary artery disease, cerebrovascular disease, universal atherosclerosis
结局指标
主要结局
cardiac flow reserve of kidney transplant patients
时间窗: supposed to be 1-3 years depending how quickly patient gets the transplant
cardiac flow reserve is measured by PET-camera during dialysis time and at one year after transplantation, unit is ml/g
renal flow reserve of kidney transplant patients
时间窗: one year
renal flow reserve of kidney transplant patients is measured by PET-camera at 3 months and at one year after transplantation, unit is ml/ml (blood/renal tissue)
次要结局
- the difference of cardiac flow reserve of kidney transplant patients who have been previously peritoneal dialysis or hemodialysis patients(supposed to be 1-3 years depending how quickly patient gets the transplant)
研究者
Johanna Paivarinta
MD
Turku University Hospital