Iodinated Contrast Opacification Gradients in Normal Coronary Arteries Imaged With Prospectively ECG-Gated Single Heart Beat 320-Detector Row Computed Tomography

Background To define and evaluate coronary contrast opacification gradients using prospectively ECG-gated single heart beat 320-detector row coronary angiography (CTA). Methods and Results Thirty-six patients with normal coronary arteries determined by 320 × 0.5 mm detector row coronary CTA were retrospectively evaluated with customized image post-processing software to measure Hounsfield Units (HU) at 1 mm intervals orthogonal to the artery center line. Linear regression determined correlation between mean HU and distance from the coronary ostium (regression slope defined as the distance gradient Gd), lumen cross-sectional area (Ga), and lumen short axis diameter (Gs). For each gradient, differences between the three coronary arteries were analyzed with ANOVA. Linear regression determined correlations between measured gradients, heart rate, body-mass index (BMI), and cardiac phase. To determine feasibility in lesions, all three gradients were evaluated in 22 consecutive patients with left anterior descending artery lesions greater than or equal to 50% stenosis. For all 3 coronary arteries in all patients, the gradients Ga and Gs were significantly different from zero (p0.503). The distance gradient Gd demonstrated nonlinearities in a small number of vessels and was significantly smaller in the RCA when compared to the left coronary system (p<0.001). Gradient variations between cardiac phases, heart rates, BMI, and readers were low. Gradients in patients with lesions were significantly different (p<0.021) than in patients considered normal by CTA. Conclusions Measurement of contrast opacification gradients from temporally uniform coronary CTA demonstrates feasibility and reproducibility in patients with normal coronary arteries. For all patients the gradients defined with respect to the coronary lumen cross-sectional area and short axis diameters are highly linear, not significantly influenced by the coronary artery (LAD vs LCx vs RCA), and have only small variation with respect to patient parameters. Preliminary evaluation of gradients across coronary artery lesions is promising but requires additional study

The Vascular Biology of Atherosclerosis and Imaging Targets

The growing worldwide health challenge of atherosclerosis, together with advances in imaging technologies, have stimulated considerable interest in novel approaches to gauging this disease. The last several decades have witnessed a burgeoning in understanding of the molecular pathways involved in atherogenesis, lesion progression, and the mechanisms underlying the complications of human atherosclerotic plagues. The imaging of atherosclerosis is reaching beyond anatomy to encompass assessment of aspects of plague biology related to the pathogenesis and complication of the disease. The harnessing of these biologic insights promises to provide a plethora of new targets for molecular imaging of atherosclerosis. The goals for the years to come must include translation of the experimental work to visualization of these appealing biologic targets in humans.Version of Recor

Coronary vasomotor dysfunction is associated with worse outcomes in patients with inflammatory disease

Abstract Background Rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), and psoriasis (PsO) are common inflammatory conditions with excess cardiovascular (CV) risk compared to the general population. This excess CV risk is associated with traditional risk factors, glucocorticoid treatment, and systemic inflammation. Systemic inflammation perturbs endothelial function and has been linked to coronary vasomotor dysfunction. It is not clear if coronary vasomotor dysfunction would be associated with worse clinical outcomes in systemic autoimmune inflammatory conditions. Purpose We tested the hypothesis that impaired coronary flow reserve (CFR), which in the absence of flow-limiting obstructive coronary artery disease (CAD) reflects vasomotor dysfunction, among patients with SLE, RA, and PsO is associated with worse clinical outcomes. Methods We included patients with RA, SLE, and PsO who underwent clinically indicated rest/stress myocardial perfusion positron emission tomography (PET) at a large academic medical center from 2006 to 2019. Patients with an abnormal myocardial perfusion study (summed stress score &amp;gt;3) or left ventricular ejection fraction &amp;lt;40% were excluded. CFR was calculated as the ratio of myocardial blood flow (MBF, ml/min/g) at peak stress compared to the MBF at rest and adjusted for baseline heart rate and blood pressure. Results Among the 175 patients (median age 65.1 years, 80% female) in the cohort, 24% had SLE, 35% PsO, and 41% RA. There was no difference in mean CFR between patients with RA, SLE, or PsO. Over a median follow-up of 8.5 years after PET, there were 47 deaths. Patients in the lowest and middle tertile (CFR &amp;lt;2.18) had a higher all-cause mortality when compared with the highest (Figure 1), and this association remained significant after adjusting for age and a composite clinical score incorporating sex, symptoms, and CV risk factors (lowest vs. highest tertile: HR 2.8; 95% confidence interval 1.2–6.5; p=0.01). CV risk factors such as diabetes, hypertension, obesity, tobacco use, and a family history of CAD were not significantly different across CFR tertiles, suggesting that inflammatory-disease specific risk factors may contribute to coronary vasomotor dysfunction. Conclusions In patients with systemic inflammatory disease, coronary vasomotor dysfunction was associated with worse outcomes independent of traditional CV risk factors and may have utility as a marker of CV risk among patients with inflammatory disease. Figure 1 Funding Acknowledgement Type of funding source: Public grant(s) – National budget only. Main funding source(s): 1. 5T32HL094301-02 NIH T32 Training Grant, “Noninvasive Cardiovascular Imaging Research Training Program” </jats:sec