Cardiology Roundup: Radiomics, Research and the FDA

2018-01-25
 


Visualization of heart with vesselsCardiac imaging continues to advance as new technologies and research influence medical practice. With such a fast rate of change, success in the profession means keeping up to date with all these trends.

In this roundup you will find news to help you stay informed on a number of topics influencing the profession. There’s a warning from the FDA on a class of MRI contrasting agents. Research confirming the safety of MRIs for patients with legacy cardiac devices. And, an opinion piece on how to drive innovative nuclear molecular research.

For those with an eye on big data and imaging, there’s a research paper demonstrating the potential for radiomics for diagnosis complex conditions.

For these stories and other highlights from the past month, read on.

1. FDA Issues New Class Warnings For GBCAs

The U.S. Food and Drug Administration (FDA) recently issued a drug safety communication requiring a new class warning and other safety measures for all gadolinium-based contrast agents (GBCAs) for magnetic resonance imaging (MRI).

The FDA recommends health care professionals consider the retention characteristics of each agent when choosing a GBCA for patients who may be at higher risk for gadolinium retention. Minimize repeated GBCA imaging studies when possible, particularly closely spaced MRI studies. However, do not avoid or defer necessary GBCA MRI scans, the warning says.

2. MRI safe in patients with legacy pacemakers, ICD

No long-term clinically significant adverse events were associated with MRI use in patients with legacy pacemakers or implantable cardioverter defibrillators, according to study results published in The New England Journal of Medicine.

Patients who have these legacy devices are often denied magnetic resonance imaging (MRI) because of safety concerns. Researchers studied 1,509 people with these devices. The patients underwent 2,103 MRI exams. The study confirms findings from the MagnaSafe registry.

3. The Challenges of Diagnosing Cardiac Sarcoidosis

This Journal of the American College of Cardiology: Cardiology Imaging article was one of the most downloaded in December. In it, researchers look at the difficult challenge of diagnosing cardiac sarcoidosis. Because there is no single reliable test for it, there are several ways to approach diagnosing it. These researchers conclude that imaging is the best method to tackle this challenge.

The researchers reported data from a two-center retrospective study that evaluated 321 consecutive patients with biopsy-proven cardiac sarcoidosis. Cardiac sarcoidosis was diagnosed in 30% of the patients on the basis of the Heart Rhythm Society (HRS) consensus criteria. The researchers compared the different criteria for the diagnosis and examined the various tests used to diagnose the condition, their sensitivity and other considerations.

The researchers concluded: “We should recognize that although we might not always know the exact histological diagnosis, imaging ultimately remains the best method for identifying the likelihood of cardiac sarcoidosis and can be used to identify patients who are at increased risk for adverse events.”

4. Radiomic Features Are Superior to Conventional Quantitative Computed Tomographic Metrics to Identify Coronary Plaques With Napkin-Ring Sign

Radiomics is a field of medical study that extracts large amount of quantitative features from medical images using data-characterization algorithms. The field has the potential to uncover disease characteristics that fail to be appreciated by the naked eye, and has been successfully used in cancer diagnosis and care.

In this paper, researchers demonstrated that radiomics can be used to identify qualitative plaque features such as the napkin-ring sign (NRS), an independent prognostic imaging marker of major adverse cardiac events.

Out of 2,674 patients referred to coronary computed tomographic angiography caused by stable chest pain, expert readers identified 30 patients with NRS plaques and matched these with 30 non-NRS plaques with similar characteristics.

5. New-generation device, better sizing eliminates TAVR survival disparity between the sexes

A larger valve option and more appropriate valve sizing using preprocedural imaging may eliminate the previously reported survival disparity between men and women undergoing transcatheter aortic valve replacement (TAVR), a new study in JACC: Cardiovascular Interventions suggests.

Men disproportionately benefited from these changes, researchers wrote, helping level the field with women, who had been previously found to experience less mortality in the wake of TAVR.

The study found no apparent sex-specific differences in survival or stroke in this trial of TAVR. This may reflect the changing demographic of patients enrolled, use of newer-generation valves with more sizes available, and more accurate valve sizing techniques.

6. Challenging Nuclear Cardiology Research: Stimulating Discovery, Validation, and Clinical Relevance

Nuclear molecular imaging allows clinicians to visualize cellular functions that influence progression of disease and therapeutic responsiveness. This makes research in this field vital, because it can deliver results that lead to life-changing drugs and gene therapies, according to the author of this editorial.

Three radiotracers, in particular, have the potential to lead to novel clinical innovations. However obstacles exist to conducting such innovative research. There are a limited number of training programs with the expertise and facilities to perform the type of imaging studies needed to train the next generation of investigators.

In addition, these early-career physicians need to be supported in their research pursuits by being given credit for grant writing, research, and teaching. Young physicians would also benefit by seeing their clinical relative-value-unit goals decrease, to allow them to the time to do research, the author concludes.

7. Coronary angiography beneficial for shockable, non-shockable cardiac rhythms

The American Heart Association and European Society of Cardiology recommend coronary angiography (CAG) routinely for patients who have had an out-of-hospital cardiac arrest (OHCA), regardless of their initial rhythm. However, this is not often done for patients who had a nonshockable rhythm, according to a study in PLOS One.

Clinical evidence underscores the need to perform this procedure on patients, whether they have a heart rhythm deemed shockable or not, the researchers said. Researchers found performing CAG led to better survival rates and good neurological outcomes for OHCA patients with initial nonshockable rhythms, as well as for those with shockable rhythms.

They investigated the clinical outcomes of 670 resuscitated adult OHCA patients. The primary outcome was 30-day survival with good neurological outcome.

Cardiac imaging plays an essential role in diagnosing and treating heart conditions, and there is always something new in development. To stay on top of what’s happening subscribe to the Medical Imaging Talk blog.

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