Advanced Cardiac Imaging in Cardiac Allograft Vasculopathy
试验速览
- 阶段
- 不适用
- 状态
- 终止
- 入组人数
- 5
- 试验地点
- 1
- 主要终点
- Number of patients with adverse events from cardiac CT and cardiac MRI scan in heart transplant patients
研究概览
简要总结
Cardiac allograft vasculopathy (CAV) is a process of both immune and non-immune mediated thickening of the heart arteries of transplanted hearts. CAV limits the long term survival of heart transplant patients and is one of the common causes of death in the late post transplant period. Current methods of detecting CAV rest with invasive cardiac catheterization which carry repeated risks, as this test needs to be performed periodically through the life of a heart transplant patient. Traditional methods of coronary angiography identify CAV late in its course and is a crude method of evaluating coronary anatomy in heart transplant patients. Intravascular ultrasound is an additive tool that is able to detect early CAV before it becomes angiographically apparent, but still requires invasive cardiac catheterization to perform. However, it also limits assessment to the major epicardial arteries and does not give any information regarding the smaller branch vessels and cardiac microvasculature. Advances in cardiac CT and cardiac MRI hold potential to evaluate for CAV non-invasively. In addition, perfusion techniques may provide additional functional information regarding the status of the microvascular.
In this pilot study, we aim to demonstrate the feasibility of cardiac CT and cardiac MRI with and without perfusion protocols, in patients post-heart transplant and to describe and compare CT and MRI findings in patients with established CAV versus those with no CAV, as diagnosed by standard invasive methods.
详细描述
Heart transplantation is a viable treatment option for select patients with end-stage heart failure, with 1-year survival rates for heart transplantation approximating 85%. Of those who survive the first year, >90% are alive at 5 years. In the early post-transplant period, rejection of the donor heart due to activation of the recipients immune system, is the most worrisome complication and most common cause of morbidity and mortality. With time, the risk of rejection declines and cardiac allograft vasculopathy (CAV) represents the most common cause of heart failure and death in heart transplant recipients. CAV is a form of coronary artery disease in the transplanted heart. It develops due to a variety of immune and non-immune mediated mechanisms. It differs significantly from coronary artery disease in normal hearts, in that it affects arteries of all sizes (not just the main arteries visible by coronary angiography) and it involves thickening of the inner layer of the arteries, rather than the surface lining of the arteries as in traditional coronary artery disease. Early CAV is clinically silent. Patients are most often diagnosed by routine coronary angiographic surveillance (standard of care), or by declining heart function by surveillance imaging (standard of care), with no evidence of any organ rejection.
Coronary angiography and assessment of heart function remain the cornerstone for diagnosis of CAV. The main limitation of angiography is its inability to identify mild or early disease, as an apparently normal angiogram can underestimate the presence of CAV. Intra-vascular ultrasound (IVUS) at coronary angiography has been evaluted as an adjunctive mordality for assessing and diagnosing early CAV. Certain IVUS parameters have been correlated with high risk for development of CAV and overall worse prognosis long term.
Detection of CAV has important therapeutic and prognostic implications. Once detected by angiography, the likelihood of progression to severe CAV within 5 years is 19%. The overall likelihood of death or re-transplantation as a result of CAV is approximately 50% for severe CAV. Changes are made to medical therapy targeted at slowing or halting CAV progression and patients are evaluated for re-transplantation sooner rather than later, depending on the rate of progression.
Currently, CAV is diagnosed by cardiac catheterization performed at routine intervals post transplant, with or without the use of IVUS. This is an invasive test with complications including bleeding, vascular damage, renal failure, stroke, heart attack or death. It has low sensitivity for identifying early CAV. Recent advances in cardiac magnetic resonance imaging (CMR) and cardiac CT imaging (CCT) present a unique opportunity to investigate these non-invasive modalities in CAV. To date, there are no studies in this field.
We propose to evaluate whether functional CCT and/or CMR perfusion abnormalities, calcium scoring by CCT, and late gadolinium enhancement by CMR, is feasible in heart transplant patients and whether these modalities can detect abnormalities that correlate to cardiac catheterization results and detect early CAV before it becomes angiographically apparent. This pilot study will be the first of its kind in the heart transplant population. We aim to demonstrate feasibility and safety of CCT/CMR in heart transplant patients and correlate specific CMR/CCT abnormalities to established angiographic apparent CAV. This will allow further prospective evaluation of this exciting non-invasive modality in CAV detection with larger research studies by our group.
研究设计
- 研究类型
- Observational
- 观察模型
- Cohort
- 时间视角
- Prospective
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
- •> 18 years of age
- •Greater than or equal to 12 months post transplant
- •Able to undergo cardiac CT and cardiac MRI
排除标准
- •Creatinine clearance less than or equal to 45ml/min per 1.73m2)
- •Severe aortic stenosis
- •Long-QT syndrome (corrected QT >440ms)
- •AV block grade II/III
- •Sick sinus syndrome
- •New York Heart Association heart failure class III/IV
- •Chronic obstructive pulmonary disease
- •Atrial fibrillation
- •Left ventricular ejection fraction <50%
- •Presence of a pacemaker or ICD
- •Presence of any metal in body
结局指标
主要结局
Number of patients with adverse events from cardiac CT and cardiac MRI scan in heart transplant patients
时间窗: Day 1
Testing the safety and feasibility of performing cardiac CT and MRI with perfusion protocols in heart transplant patients. Adverse events: serum creatinine increase \>25% from baseline within 1 week, drop in systolic blood pressure \>30mmHg, arrhythmias, chest pain, shortness of breath during drug infusion for perfusion protocols, inability to reduce heart rate \<80bpm for cardiac CT.
次要结局
- Describe CT and MRI imaging findings of established CAV(Day 1)
- Correlation between intimal thickening by IVUS imaging at cardiac catheterization and CCT and CMR perfusion abnormalities(Day 1)
- The association between CCT/CMR perfusion abnormalities one year post transplant and the development of angiographically apparent CAV, graft dysfunction, cardiac adverse events, and overall survival long term(10 years)