Diagnostic Imaging Tools IVUS and FFR Offer More Targeted Cardiology Treatments for Patients
Every 36 seconds, an American dies from heart disease.
It’s a startling statistic, but far from a surprising one considering heart-related illnesses have become the leading cause of death domestically. And the consequences extend beyond the human toll — heart disease costs the U.S. economy approximately $363 billion each year, including the cost of healthcare services and medicines.
The most prevalent type of heart disease in the U.S. is coronary artery disease (CAD), which affects an estimated 18.2 million adults ages 20 and older and is caused by cholesterol buildup and plaque in the coronary arteries that impede normal blood flow to the heart. CAD has modifiable risk factors, such as hypertension, hyperlipidemia, smoking, diabetes, excess weight, lack of physical activity and poor diet, as well as nonmodifiable risk factors including family history of premature heart disease, age and gender.
When modifying risk factors and introducing pharmacologic agents are not enough to resolve coronary disease, patients may need interventional cardiology treatments such as angioplasty with stent coronary revascularization and coronary artery bypass graft (CABG). Traditionally, stents are used on vessels with at least 70% obstruction, as they can rapidly reestablish coronary artery blood flow in patients with acute myocardial infarctions.
However, accurately estimating vessel lesions with angiography is often difficult because the lesions are not smooth or uniform. That’s where intravascular ultrasound (IVUS) and fractional flow reserve (FFR) come in. By adding IVUS and FFR as diagnostic imaging tools to complement angiography, physicians will have a far more complete picture of patients’ coronary conditions.
Intravascular ultrasound explained
Intravascular ultrasound, also known as endovascular ultrasound or intravascular echocardiography, employs a special catheter with a small ultrasonic transducer. The specialist threads the catheter through a patient’s artery or vein to the target location, and the transducer then generates sound waves to produce pictures of the inner blood vessels to help assess various conditions.
Interventional cardiologists use IVUS to assist in the diagnoses of both the arteries and the veins and determine plans of care. In veins, specialists most often use IVUS for acute and chronic blood clots, particularly if they suspect the clots were caused by narrowing of the veins. IVUS can help identify areas of narrowing or blockage deep in the body and helps measure veins for appropriate sizing of stents. It provides imaging of the coronary arteries in conjunction with, or to help plan for, catheter angiography or angioplasty and vascular stenting, and unlike angiography, IVUS can show the entire artery wall and reveal more information about plaque buildup (atherosclerosis).
Information from IVUS can assist in determining treatment decisions, including stent size and where it should be placed. Interventional cardiologists often use IVUS after angioplasty and vascular stenting to confirm that the stent is in the right place and that it has corrected the problem. In a recent study, IVUS use altered procedures 74% of the time. Changes included use of larger stents or balloons, additional post-dilation and additional stenting. IVUS also helped indicate higher pressures in patients, which resulted in lower rates of stent thrombosis, myocardial infarction and target lesion revascularization. Use of IVUS technology can lead to optimal stent placement and reduce adverse cardiac events.
Importance and benefits of FFR
Coronary pressure-derived FFR rapidly assesses the blood flow of individual coronary artery lesions and can be performed in the catheterization laboratory. Cardiologists can use FFR to effectively guide coronary revascularization procedures, leading to improved patient outcomes.
In addition to improving patient outcomes, FFR facilitates treatment decision making and helps avoid unnecessary medical procedures. It does this by providing a measurable ratio of the actual blood flow in a narrowed artery compared with the normal achievable blood flow — the measurement is more accurate in diagnosing ischemic lesions than angiography alone. Using this functional measurement, FFR quantifies the severity of specific stenoses, and FFR technology can help specialists identify ischemia-inducing stenosis with greater than 90% accuracy.
Experts attribute a 16% compound annual growth rate for FFR primarily to the:
- Aging U.S. population and the associated increase in cardiovascular diseases
- Cost benefits of FFR
- Presence of a favorable Medicare reimbursement scenario
As more patients experience heart conditions, early detection and intervention remain critical goals for healthcare providers. Leveraging new and evolving diagnostic tools and medical imaging techniques such as IVUS and FFR can help improve overall patient care.