Background and aims: Different methodologies to report whole-heart atherosclerotic plaque on coronary computed tomography angiography (CCTA) have been utilized. We examined which of the three... Show moreBackground and aims: Different methodologies to report whole-heart atherosclerotic plaque on coronary computed tomography angiography (CCTA) have been utilized. We examined which of the three commonly used plaque burden definitions was least affected by differences in body surface area (BSA) and sex.Methods: The PARADIGM study includes symptomatic patients with suspected coronary atherosclerosis who underwent serial CCTA > 2 years apart. Coronary lumen, vessel, and plaque were quantified from the coronary tree on a 0.5 mm cross-sectional basis by a core-lab, and summed to per-patient. Three quantitative methods of plaque burden were employed: (1) total plaque volume (PV) in mm(3), (2) percent atheroma volume (PAV) in % [which equaled: PV/vessel volume * 100%], and (3) normalized total atheroma volume (TAV(norm)) in mm(3) [which equaled: PV/vessel length * mean population vessel length]. Only data from the baseline CCTA were used. PV, PAV, and TAV(norm), were compared between patients in the top quartile of BSA vs the remaining, and between sexes. Associations between vessel volume, BSA, and the three plaque burden methodologies were assessed.Results: The study population comprised 1479 patients (age 60.7 +/- 9.3 years, 58.4% male) who underwent CCTA. A total of 17,649 coronary artery segments were evaluated with a median of 12 (IQR 11-13) segments per-patient (from a 16-segment coronary tree). Patients with a large BSA (top quartile), compared with the remaining patients, had a larger PV and TAV(norm), but similar PAV. The relation between larger BSA and larger absolute plaque volume (PV and TAV(norm)) was mediated by the coronary vessel volume. Independent from the atherosclerotic cardiovascular disease risk (ASCVD) score, vessel volume correlated with PV (P < 0.001), and (P = 0.003), but not with PAV (P = 0.201). The three plaque burden methods were equally affected by sex.Conclusions: PAV was less affected by patients body surface area then PV and TAV(norm) and may be the preferred method to report coronary atherosclerotic burden. Show less
Despite the available treatment options and sophisticated imaging technologies for monitoring lesion development, the morbidity and mortality from acute cardiovascular events remain unacceptably... Show moreDespite the available treatment options and sophisticated imaging technologies for monitoring lesion development, the morbidity and mortality from acute cardiovascular events remain unacceptably high.While cholesterol-lowering, anti-inflammatory and anti-platelet therapies benefits can increase survival as a primary or secondary prevention, they are not sufficient for plaque rupture prevention. Moreover, the most advance imaging technologies to detect high-risk atherosclerotic patients fail to visualize and explore cellular events in small preclinical models. Therefore, there is a clear need for the development of new therapies and the application of high-resolution imaging modalities.In the current thesis, we evaluated new possibilities to inhibit and image intraplaque angiogenesis. Show less
Cardiovascular risk assessment in patients with diabetes mellitus (DM) remains challenging. Risk scores to predict cardiovascular risk are widely used, but are developed in the general population... Show moreCardiovascular risk assessment in patients with diabetes mellitus (DM) remains challenging. Risk scores to predict cardiovascular risk are widely used, but are developed in the general population and tend to underestimate the cardiovascular risk of DM patients. Risk scores developed in diabetic populations to estimate cardiovascular risk have demonstrated good calibration and discriminations indices. However, external validation is still needed. A recent meta-analysis showed that the predictive ability of these scores developed in diabetic populations is not superior to those scores developed in general population. Accordingly, the additional use of other biomarkers or imaging tools seems a good alternative to better risk stratify diabetic patients. This thesis evaluates the application and performance of non-invasive cardiac imaging tests for cardiovascular risk assessment and management of DM patients. Identification of new markers of CAD derived from non-invasive cardiac imaging might result in a broader applicability of cardiovascular risk assessment. Non-invasive cardiac imaging tests might evaluate target organ damage as well as the presence, severity and extent of subclinical atherosclerosis preceding overt clinical CAD. Thus, high-risk patients for CAD can be identified and further decision making of each DM patient can be tailored in order to improve the clinical outcomes at long-term follow-up Show less
Non-invasive imaging plays an increasingly important role in the diagnosis and risk stratification of coronary artery disease. Several techniques such as stress echocardiography and myocardial... Show moreNon-invasive imaging plays an increasingly important role in the diagnosis and risk stratification of coronary artery disease. Several techniques such as stress echocardiography and myocardial perfusion imaging have become available to assess cardiac function and myocardial perfusion. With the arrival of multi-slice computed tomography coronary angiography (CTA), non-invasive imaging of coronary anatomy has also become possible. CTA is a relatively new imaging technique; the objective of the thesis is therefore to explore the value of CTA for diagnosis and risk stratification of CAD in patients presenting with suspected and known CAD, in order to further define its role in clinical practice. The results of this thesis show that CTA provides important diagnostic information relative to existing non-invasive imaging strategies. In addition the detailed anatomic information obtained using CTA was shown to provide important prognostic information. CTA supplies complementary information to existing non-invasive imaging techniques, and has the potential to provide a more patient tailored approach to patient management. What remains to be determined is how CTA and non-invasive functional imaging should be integrated into clinical practice. Show less
Current non-invasive detection of coronary artery disease (CAD) is based on demonstration of ischemia using stress-rest imaging: this is an indirect way of identifying CAD by demonstration of the... Show moreCurrent non-invasive detection of coronary artery disease (CAD) is based on demonstration of ischemia using stress-rest imaging: this is an indirect way of identifying CAD by demonstration of the hemodynamic consequences rather than direct visualization of the obstructive lesions in the coronary arteries. Multi-slice computed tomography (MSCT) has recently emerged as an extremely rapidly developing non-invasive imaging modality, which allows anatomical imaging of the coronary arteries, or non-invasive coronary angiography. In addition, total plaque burden, plaque morphology and (to some extent) plaque constitution can be assessed by MSCT. The technique also provides information on resting left ventricular systolic function, and possibly resting perfusion. Ideally, stress function and perfusion should also be evaluated, since this would allow detection of ischemia and would complete the picture on CAD. However, this is not routinely performed, since sequential acquisitions are associated with high radiation doses and thus pose a limitation for cardiovascular applications of MSCT. It is anticipated that, with reduction in radiation, MSCT may become an important player in the diagnostic and prognostic workup of patients with known or suspected CAD. Show less
Various modalities are available in the diagnostic and prognostic evaluation of patients presenting with known or suspected coronary artery disease (CAD). A rapidly expanding technique is... Show moreVarious modalities are available in the diagnostic and prognostic evaluation of patients presenting with known or suspected coronary artery disease (CAD). A rapidly expanding technique is noninvasive coronary angiography with Multi-Slice Computed Tomography (MSCT), which allows accurate detection of significant stenoses. The main value of the technique lies in the noninvasive exclusion of CAD in patients with intermediate pre-test likelihood. Although imaging in populations such as patients with previous stent placement appears to be more challenging, promising results have been obtained in these populations as well. However, it remains important to realize that the presence of coronary atherosclerosis with luminal obstruction does not invariably imply the presence of ischemia. Accordingly, a noninvasive angiographic imaging technique as MSCT cannot be used to predict the hemodynamical importance of lesions. In patients with borderline stenosis, therefore, functional testing (which can be performed by nuclear imaging, stress echocardiography or MRI) will remain necessary to determine management. Nonetheless, detection of CAD at a far earlier stage than functional imaging is an important advantage of MSCT. Initial investigations suggest that MSCT may distinguish different plaque characteristics between various presentations. Potentially, this information could be useful for risk stratification. Finally, additional non-coronary information can be derived as well. LV function can be evaluated with high accuracy while also information on the cardiac venous system can be obtained. Show less
