Evaluation of the prognostic significance of myocardial perfusion defects, wall motion abnormalities and late gadolinium enhancement in MRI of asymptomatic diabetics and healthy subjects

根据世界卫生组织的数据，到2025年，全球糖尿病患病率将从1985年的3000万增加到至少3亿。糖尿病患者发生重大不良心脏事件(MACE)的风险增加了数倍。早期风险分层对于启动预防措施是必要的。该研究的目的是验证心血管磁共振(CMR)在无症状糖尿病患者和非糖尿病患者中有关MACE的预后价值。尽管已经进行了相关研究，但它们都受到了选择偏差的影响，导致队列中主要包含有症状的受试者。从医学角度来看，无症状人群有望从仍处于亚临床阶段的早期发现和治疗中获益最多。因此，这项工作的主要动机是更好地理解和解释病理性CMR发现可能带来的患者护理的潜在好处。为了实现这一点，我们将分析已经获得的纵向和横断面CMR研究的数据，其中300名无症状、糖尿病(n=51)和健康(n=249)的志愿者与相同的心血管危险因素的患病率匹配。所有受试者(±7岁，女性33%)均行CMR成像，包括电影序列、心肌负荷和静息首过灌注序列和T1加权倒置恢复梯度回波序列。在我们项目的第一部分，我们将分析CMR数据，以定量评估左心功能和容量、室壁运动异常和晚期Gd增强。应激诱导的心肌缺血将进行直观和半定量的分析。根据美国心脏协会的17节段模型，糖尿病患者和非糖尿病患者之间的患病率将被记录下来并进行比较。为了确定CMR结果的预后意义，已经并仍在监测MACE的发生。为了考察CMR结果作为预后工具的附加值，我们将分别对两组患者与病史、体格检查、血液检查和电子束计算机断层扫描-钙化评分等临床确定的危险因素进行比较。因此，我们将进行回归分析，以确定与这些既定风险因素的关联。在日常的临床工作中，CMR已经成为评估心血管疾病的重要工具。这项队列研究将证实先前关于有症状的糖尿病患者的研究结果是否可以应用于无症状的糖尿病患者，这些研究涉及CMR结果的高度预后相关性。如果我们成功地证实了CMR结果作为无症状糖尿病患者和非糖尿病患者MACE的预测工具的附加值，CMR作为风险分层工具的重要性将进一步加强。

According to the WHO the global prevalence of diabetes mellitus is set to increase from 30 million in 1985 to at least 300 million by 2025. Diabetics bear a multifold risk-increase for major adverse cardiac events (MACE). Early risk stratification is necessary to initiate preventive measures. The aim of the proposed research is to validate the prognostic value of cardiovascular magnetic resonance (CMR) concerning MACE in asymptomatic diabetics and non-diabetics. Although related studies have already been conducted, they were all compromised by a selection bias that resulted in cohorts containing mainly symptomatic subjects. From a medical perspective it is the asymptomatic population that promises to benefit the most from an earlier detection and treatment at a still subclinical stage. The main motivation for this work is therefore the potential benefit for patient care that could result from a better understanding and interpretation of pathological CMR findings.To achieve this, we are going to analyse already acquired data of a longitudinal and cross-sectional CMR-study with a population of 300 asymptomatic, diabetic (n=51) and healthy (n=249) volunteers matched to the same prevalence of cardiovascular risk factors. All subjects (64±7 years; 33% female) underwent CMR imaging including cine sequences, myocardial stress and rest first pass perfusion and T1 weighted inversion recovery gradient echo sequences. In the first part of our project we will analyse the CMR data in order to quantitatively assess left ventricular function and volumes, wall motion abnormalities and late gadolinium enhancement. Stress-induced myocardial ischemia will be analysed visually and semi-quantitatively. Based on the American Heart Association 17-segment model, the prevalence of findings will be documented and compared between diabetics and non-diabetics. To determine the prognostic significance of CMR findings, the occurrence of MACE has been and is still being monitored. In order to scrutinize the added value of CMR-findings as a prognostic tool, a comparison with clinically established risk factors derived from medical history, physical examination, blood tests, and electron beam computed tomography-calcium scoring will be conducted for both groups separately. Therefore, we will perform regression analyses to determine the association with these established risk factors. In daily clinical routine, CMR already is an established and vital tool for the assessment of cardiovascular pathologies. This cohort study will confirm whether the results of previous studies on symptomatic diabetics, concerning the high prognostic relevance of CMR findings, can be applied to asymptomatic diabetics. If we are successful in substantiating the added value of CMR findings as a predictive tool for MACE in asymptomatic diabetics and non-diabetics, the significance of CMR as a risk-stratification-tool would be further strengthened.