Application of cardiac imaging modalities in the assessment of coronary artery disease

Abstract

In this thesis, Cardiac MRI and intravascular imaging have been used to address the challenges in coronary artery disease.

A novel high-resolution 3-dimensional magnetic resonance imaging method for quantifying infarct size and area at risk in a rodent model was developed and validated. Two contrast agents, microparticles of iron oxide and gadolinium were used to demarcate the area at risk and myocardial infarction.

In order to understand the clinical indications for use of Optical Coherence Tomography (OCT), a single centre experience where OCT was used to help guide management in routine percutaneous coronary intervention (PCI) is reported.

There is limited data on how well two-dimensional Quantitative Coronary Angiography (2D-QCA) and OCT agree with each other for measurement of coronary artery lumen dimensions. In this comparison study, there was a good correlation and agreement between 2D-QCA and OCT for measurement of proximal and distal reference diameters of a coronary vessel. However, the minimum luminal diameter was underestimated by 2D-QCA.

A higher in-hospital and 30 day mortality has been observed in patients who present with a myocardial infarction and have no standard modifiable cardiovascular risk factors (SMuRFs) as compared to patients with one or more SMuRFs. In this Intravascular ultrasound study, The SMuRFless patients had a lower plaque burden and calcification at baseline but the rate of progression of plaque was similar to patients with SMuRFs.

In this cardiac MRI study, there was no difference in 30-day mortality however SMuRFless patients had a larger infarct size and a smaller myocardial salvage index. This association was mediated by a larger proportion of left anterior descending artery (LAD) culprit lesions and poor TIMI flow pre-PCI. Interestingly, the proportion of patients with culprit LAD and TIMI 0-1 flow pre-PCI was significantly higher in SMuRFless patients.