Cardiac amyloidosis has gained a massive amount of attention the past couple years due to the development and U.S. Food and Drug Administration (FDA) clearance of the first drug treatments. Prior to therapies being available, imaging for cardiac amyloidosis was a largely ignored.
The demand for cardiac amyloid imaging has risen to a point where the American Society of Nuclear Cardiology (ASNC) is developing an information statement to support quality improvement. Fadi Hage, MD, director of nuclear cardiology at the University of Alabama at Birmingham and chief of cardiology at the Birmingham VA medical center, is the chair of the document’s writing committee.
ASNC’s forthcoming quality metrics document will define four axes for standardization of imaging when cardiac amyloidosis is suspected. Cardiovascular Business spoke with Jamieson Bourque, MD, lead author of the document’s Appropriate Indications axis and medical director of the nuclear cardiology and stress laboratory as well as the medical director of the echocardiography lab at the University of Virginia. He expects ASNC’s quality metrics document will publish by mid-2024. It will build on previously published cardiac amyloid practices points and expert opinions.[1-5]
Cardiac amyloidosis, characterized by the abnormal accumulation of amyloid proteins in the heart tissue, has seen significant advancements in imaging as well in recent years. Driven by the emergence of drugs designed to treat the condition, the need for accurate and comprehensive imaging techniques has become paramount.
"It's been a whole new area of imaging for us, an exciting new indication for radionuclide imaging and allows us to noninvasively diagnosed patients with transthyretin amyloid cardiomyopathy (ATTR-CM) cardiac amyloidosis so those patients can be started on new therapies that have been identified that are improving quality of life, reducing hospitalizations and improving survival. There's some early medications available and there are new ones coming down the pipeline. So it is a very exciting time for us for a disease process that has been under-recognized and underdiagnosed," Bourque explained.
Need to clearly identify subtypes of amyloidosis for targeted therapy
With multiple subtypes of cardiac amyloidosis, it becomes crucial to identify the specific subtype for targeted therapy. Bourque said that among the various subtypes, ATTR and amyloid light chain (AL) are the most common.
In cardiac nuclear imaging, he said, while SPECT imaging is effective for diagnosing ATTR, it cannot be used to diagnose AL cardiac amyloidosis. F-18 PET tracers are able to assess both AL and ATTR cardiac amyloidosis, but they do not yet have approval for that indication.
"There is increasing research use of these agents and eventually, I strongly suspect, there will be clinical applications," Bourque said.
Impact of cardiac amyloid quality metrics on clinical practice
The potential impact of ASNC’s quality metrics document lies in guiding clinicians on when nuclear cardiology is most beneficial and on best practices. Bourque emphasizes the importance of providing clarity on situations where imaging techniques prove helpful.
"It is going to be important to help clinicians understand times or specific situations where this sort of imaging would be helpful and times when it wouldn't be helpful," Bourque explained.
Read more on the rising area of amyloid imaging from the echocardiography side at ASE 2023 in Amyloidosis now a hot topic in cardiac imaging due to new drug treatment.
Dave Fornell has covered healthcare for more than 17 years, with a focus in cardiology and radiology. Fornell is a 5-time winner of a Jesse H. Neal Award, the most prestigious editorial honors in the field of specialized journalism. The wins included best technical content, best use of social media and best COVID-19 coverage. Fornell was also a three-time Neal finalist for best range of work by a single author. He produces more than 100 editorial videos each year, most of them interviews with key opinion leaders in medicine. He also writes technical articles, covers key trends, conducts video hospital site visits, and is very involved with social media. E-mail: dfornell@innovatehealthcare.com