None listed
Conditions
Brief summary
Cardiovascular disease remains a leading cause of death and disability in our community, with atherosclerosis being the major disease process underlying the majority of heart attacks. Atherosclerosis is a disease in which plaques made up of fat (cholesterol) builds up in the wall of an artery. As plaque builds up it can narrow the coronary artery and reduce blood flow to your heart muscle. There is also a risk that the plaque may rupture causing a sudden blockage of the artery. This can cause a heart attack, which results in permanent damage to heart muscle. However, there is little understanding of how plaques grow in the arteries and what makes certain plaques at high-risk of causing a heart attack. Recent experimental data has suggested that the force the blood exerts on the wall of the artery (shear stress) may be important in promoting plaque growth and even rupture. Measurement of shear stress in humans is challenging and is currently performed via a coronary angiogram combined with specialist invasive imaging. These images allow us to create a three-dimensional model of the arteries to the heart on a computer. Shear stress can then be calculated using highly specialist software that models blood flow in the arteries. At present, shear stress calculations can only be performed following an invasive medical procedure. This means we cannot calculate shear stress for the majority of patients with suspected coronary artery disease. CT coronary angiography (CTCA) is an established, safe, rapid and convenient non–invasive method to diagnose the presence of coronary artery disease. CTCA also provides useful information on the size and composition of coronary plaque. However, the ability of CTCA to calculate shear stress in coronary arteries is unknown. If this project is successful, then shear stress calculations could be performed based on CTCA images, which would allow clinicians to explore whether this force is responsible for plaque growth or rupture in humans.
Interventions
Patients with non-obstructive atherosclerotic plaque at coronary angiography will undergo both invasive (the gold-standard) and non-invasive assessment of endothelial shear stress (ESS). Non-invasive assessment of ESS will be performed using CT coronary angiography (CTCA) within one month of the invasive assessment. This will be performed on a 320-slice CT scanner following administration of medication (e.g. beta-blockers) to control heart rate, in accordance with published guidelines. Image acq
Patients with non-obstructive atherosclerotic plaque at coronary angiography will undergo both invasive (the gold-standard) and non-invasive assessment of endothelial shear stress (ESS). Non-invasive assessment of ESS will be performed using CT coronary angiography (CTCA) within one month of the invasive assessment. This will be performed on a 320-slice CT scanner following administration of medication (e.g. beta-blockers) to control heart rate, in accordance with published guidelines. Image acquisition will require injection of contrast agent and participants to lie flat for around 15mins. Following CTCA acquisition, 3D reconstruction of the coronary arteries will be performed with this model used as basis of computational fluid dynamic simulations. ESS will be calculated throughout the arterial tree and these values compared with that derived invasively. Providers and readers of the index tests will have full access to clinical information and previous test results. The results of the research CTCA will be available to the treating physician.
Sponsors
MonashHeart
Eligibility
Sex/Gender
All
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
1) Age greater or equal to 18 years of age. 2) Able to provide informed consent 3) Undergoing (or due to undergo) invasive coronary angiography for clinical reasons
Exclusion criteria
1) Chronic renal failure with eGFR < 30 ml/min 2) Previous coronary artery bypass surgery 3) Left ventricular ejective fraction < 50% or known regional wall motion abnormality on echocardiogram 4) Atrial fibrillation 6) Moderate or severe aortic stenosis or left ventricular outflow tract gradient 7) Decompensated heart failure 8) Severe asthma or resting bradycardia precluding use of adenosine 9) Unfavourable coronary anatomy that would prohibit safe intracoronary imaging 10) Women of childbearing age
Outcome results
None listed