Physiology made simple

Coronary angiography is an imaging defined as the radiographic visualization of the coronary vessels after injection of radiopaque contrast media. It’s usually done using special catheters during cardiac catheterization, which can also involve imaging other blood vessels like the aorta and left ventricle. The resulting X-ray images, known as angiograms, play a crucial role in assessing the degree of luminal obstruction of the coronary arteries. While coronary angiography is versatile and can be applied to different areas of the body, it’s particularly vital when it comes to evaluating the arteries of the heart.

A coronary angiogram specifically focuses on the arteries in the heart. This procedure provides a detailed X-ray view of these arteries, offering valuable insights into the presence and severity of heart disease. It serves as a fundamental tool for determining the overall functionality of the heart.

The Role of Coronary Angiography in Treatment Decisions

Once a coronary angiogram is performed, the gathered information becomes instrumental in guiding treatment decisions. Coronary angiography is a pivotal diagnostic tool in interventional cardiology, allowing to assess the degree of arterial narrowing and determine the need for further interventions. Armed with this information, interventional cardiologists can collaborate with patients to determine the most appropriate treatment plan, which may include stent placement, bypass surgery, or medication. Understanding the significance of coronary angiography empowers healthcare professionals to make informed decisions that improve patient outcomes in the field of interventional cardiology.

Reference

https://www.ahajournals.org/doi/pdf/10.1161/01.cir.99.17.2345

Fractional flow reserve (FFR) is a measure used during coronary angiography to assess the risk of coronary stenosis causing myocardial ischemia. It quantifies reduced blood flow due to coronary disease and guides treatment decisions. Clinical trials support using percutaneous coronary intervention (PCI) for ischemic lesions (FFR ≤0.80) over medical therapy. For nonischaemic FFR lesions (FFR >0.80), PCI isn’t recommended.

FFR calculates maximal blood flow with a stenosis compared to normal flow. It’s easily derived from pressure ratios during vasodilation, unaffected by systemic changes, and considers collateral blood supply. Normal FFR is 1.0, and FFR below 0.75 indicates significant stenoses associated with myocardial ischemia.

References

Pijls N. et al., Measurement of Fractional Flow Reserve to Assess the Functional Severity of Coronary-Artery Stenoses. N Engl J Med 1996; 334:1703-1708. DOI: 10.1056/NEJM199606273342604

https://jamanetwork.com/journals/jama/fullarticle/2773127

https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2796612

Fractional flow reserve (FFR) is an invasive method for evaluating the functional significance of coronary stenosis using a pressure wire. Quantitative flow ratio (QFR) is a comparable angiography-based approximation of FFR. Unlike FFR, QFR does not require the use of a pressure wire nor the administration of a hyperaemic agent like adenosine. This emerging technology seems to be precise and could serve as a valuable substitute for FFR.

References

Toong C. et al., Diagnostic performance of QFR vs FFR. International Journal of Cardiology (2021). DOI:https://doi.org/10.1016/j.ijcard.2021.10.129

Westra J. et al., Evaluation of Coronary Artery Stenosis by Quantitative Flow Ratio During Invasive Coronary Angiography. Circulation Cardiovascular Imaging (2018). doi.org/10.1161/CIRCIMAGING.117.007107

Quantitative flow ratio (QFR^®) is an innovative technique that allows for the calculation of FFR (Fractional Flow Reserve) using three-dimensional quantitative coronary angiography (3D QCA) constructed from two angiograms. Unlike traditional methods, QFR does not rely on hyperaemic agents like adenosine, and there’s no necessity for a pressure wire. QFR has a user-friendly interface and offers a straightforward, valuable, and non-invasive approach to assess the functional importance of coronary artery stenosis.

Reference