Coronary artery disease
Coronary artery disease (CAD) is the leading cause of mortality globally.
CAD is asymptomatic in most of the population. When severe enough it can cause angina or an acute coronary syndrome including myocardial infarction. CAD may also present with heart failure or sudden cardiac death.
CAD is primarily due to atherosclerosis, an inflammatory process that leads to atheroma development and remodelling/stenosis of the coronary arteries. A stenosis of >50% of diameter or >75% cross-section diameter reduction can lead to angina. Thrombus formation after plaque disruption can lead to acute coronary syndrome 1,2.
- non-modifiable: family history, age, male sex 1
- modifiable: hypercholesterolemia, left ventricular hypertrophy, obesity, hypertension, diabetes, sedentary lifestyle, smoking, alcohol 1
There are a variety of techniques to image coronary artery disease including both anatomical and functional modalities. Coronary angiography has been the mainstay for many years, but in certain patient groups is being replaced by non-invasive imaging such as coronary CT angiography (cCTA).
There are several appropriate clinical indications for the performance of coronary CTA 8:
- acute chest pain in patients with a low-to-intermediate pretest probability of CAD
- evaluation of coronary artery anatomy and bypass grafts
- assessment of congenital heart disease
- coronary artery calcium scoring
- patients with technically limited images from echocardiography or MRI
Haemodynamically significant stenoses are those >70% for all coronary arteries, except the left main coronary artery where >50% stenosis is considered significant 7.
The recently proposed SCCT grading scale for stenosis severity assesses degree of luminal diameter stenosis 6:
- 0% = no visible stenosis
- 1-24% = minimal stenosis
- 25-49% = mild stenosis
- 50-69% = moderate stenosis
- 70-99% = severe stenosis
- 100% = occlusion