Serial intravascular ultrasound assessment of coronary atherosclerosis progression and remodeling

Cardiovascular disease is a major cause of morbidity and mortality in countries with western lifestyle. Reliable quantitative assessment of the extent of coronary atherosclerosis during the natural history of coronary artery disease and following therapeutic interventions is important to evaluate disease progression and antiatherosclerotic therapies. Coronary angiography visualizes the luminal silhouette but not the vessel wall where the atherosclerotic disease process is actually located. Intravascular ultrasound (IVUS), however, provides transmural tomographic images of the coronary artery and direct measurements of lumen, plaque, and vessel dimensions. Serial IVUS measurements allow to quantify the extent of coronary plaque progression or regression and changes in total vessel dimensions (remodeling process) as introduced in Chapter 1. The Chapters 2-4 of this thesis focus on the relation between serum parameters and progression-regression of coronary atherosclerosis in the left main stem as assessed with serial IVUS. In addition, Chapter 5 explores the relation between the risk of cardiovascular events and IVUS assessed plaque progression-regression. The Chapters 6-8 investigate the remodeling behaviour of coronary lesions in a serial IVUS design by providing (1) evidence of serial remodeling (Chapter 6), (2) the validation of the non-serial assessment of coronary remodeling (Chapter 7), and (3) the validation of Glagov's histopathological remodeling hypothesis. Chapter 9 assesses measurement differences between different IVUS devices in vitro and validated dedicated calibration formulas for correction. Chapter 10 focuses on volumetric radiofrequency-based IVUS analysis of atherosclerotic plaque composition and evaluates the reproducibility of this technique for the use in studies with a serial design. Finally, Chapter 11 reviews the current knowledge of coronary atherosclerosis that was been gained from observational and randomized pharmacological intervention trials with serial IVUS.