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

据世界卫生组织称，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。糖尿病患者发生主要心脏不良事件（MACE）的风险增加了数倍。早期风险分层对于采取预防措施是必要的。本研究的目的是验证心血管磁共振（CMR）对无症状糖尿病和非糖尿病患者MACE的预后价值。虽然已经进行了相关研究，但它们都受到选择偏差的影响，导致队列主要包含有症状的受试者。从医学角度来看，无症状人群有望从亚临床阶段的早期检测和治疗中获益最多。因此，这项工作的主要动机是通过更好地理解和解释病理CMR结果，为患者护理带来潜在的好处。为了实现这一目标，我们将分析已经获得的纵向和横断面cmr研究数据，该研究包括300名无症状、糖尿病（n=51）和健康（n=249）志愿者，他们的心血管危险因素的患病率相同。所有受试者（64±7岁，女性33%）均行CMR成像，包括电影序列、心肌应激和休息第一次灌注和T1加权反转恢复梯度回波序列。在我们项目的第一部分，我们将分析CMR数据，以定量评估左心室功能和容积、壁运动异常和晚期钆增强。对应激性心肌缺血进行目测和半定量分析。根据美国心脏协会的17节段模型，研究结果的患病率将被记录下来，并在糖尿病患者和非糖尿病患者之间进行比较。为了确定CMR结果的预后意义，MACE的发生一直并仍在监测中。为了检验cmr结果作为预后工具的附加价值，将对两组患者分别与病史、体格检查、血液检查和电子束计算机断层扫描钙评分得出的临床确定的危险因素进行比较。因此，我们将进行回归分析，以确定与这些既定危险因素的关联。在日常临床常规中，CMR已成为评估心血管病理的重要工具。本队列研究将证实以往关于症状性糖尿病的研究结果，即CMR结果与预后的高相关性，是否可以应用于无症状性糖尿病。如果我们成功地证实CMR结果作为无症状糖尿病和非糖尿病患者MACE预测工具的附加价值，CMR作为风险分层工具的意义将进一步加强。

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.