An Investigation of Coronary CT Angiography Variables in Relation to the Development of Atherosclerosis

In the last five years, cardiac disease has been reported as the second leading cause of death in Taiwan. In 2011, there were 16,571 deaths due to cardiac disease, which constituted 10.9% of all deaths in Taiwan. Coronary artery disease (CAD) is also a major socioeconomic issue due to its high health care expenditure. During the past decade, coronary CT angiography (CCTA) has been increasingly used as an effective less invasive modality for diagnosis of CAD due to its improved spatial and temporal resolution. In addition to accurately assess the degree of coronary stenosis, CCTA enables visualization of atherosclerotic plaques. This is represented in its ability to identify the location and distribution of plaques in the coronary arteries, characterize the type of plaques as well as assess the plaque composition. Since the angulation of the bifurcation of left coronary artery might have an effect on haemodynamic shear stress and consequently on plaque size and development, measurement of the bifurcation angles will provide an insight into demonstrating the relationship between plaques and coronary angles. It is proposed in previous studies that a wider bifurcation angle might be related to higher turbulence and low shear stress, whereas a narrow angle might be more prone to present laminar flow. However, to the best of our knowledge, there is no systematic analysis of the correlation between left coronary angulation and subsequent coronary dimensional changes and development of CAD. The proposed study plans to correlate plaque formation with the left bifurcation angle with aim of identifying the risk factor for atherosclerosis leading to CAD. It is expected that research findings of this study will contribute significantly to accurate assessment of plaque morphology, coronary wall change, risk stratification and patient management. In our affiliated hospital, a 64-slice CT machine was installed in May 2006, and a 640-slice CT scanner was installed in August 2009. Around 2,435 cases of CCTA were performed in the last six and half years. This retrospective study will collect 1,000 cases of patients who had CCTA. These 1,000 cases will be divided into three groups. Group I comprises subjects with normal coronary arteries; group II comprises subjects with abnormal left coronary arteries but without CAD, while group III are composed of subjects who had CAD of left coronary arteries. The conventional risk factors of CAD of all 1,000 subjects will be recorded. The findings of CCTA, including calcium scoring and degree of stenosis of four coronary arteries, left coronary angulation, the arterial diameter, location, distribution, pattern and components of atherosclerotic plaques of the left main coronary artery, left anterior descending artery and left circumflex artery will be analyzed and recorded. Finally, the correlation among the left coronary angulation, plaques characteristics and CAD will be investigated and analyzed.

Project ID:PC10207-0434
External Project ID:NSC102-2314-B182-056