New biomarker predicts severity of cardiac remodeling after myocardial infarction

Representative case with acute anterior wall myocardial infarction: myocardial perfusion images with 99mTc-tetrofosmin at rest (first row), 68Ga-FAPI-46 PET (second row), late gadolinium enhancement (LGE) from cardiac magnetic resonance (third row) and schematic drawings of the left ventricle (fourth row). The area of ​​fibroblast activation exceeds the infarct area and the LGE signal, the most common mode of myocardial FAP distribution. Bottom left: Mean areas of perfusion defect, FAPI signal and LGE from 35 patients examined. Bottom right: Global myocardial FAP volume early after acute myocardial infarction is inversely correlated with left ventricular ejection fraction (LV-EF) at follow-up in the chronic stage (n=14 patients). Photo credits: Johanna Diekmann, James Thackeray, Thorsten Derlin, Christoph Czerner, Tobias Ross and Frank Bengel, Clinic for Nuclear Medicine, Hannover Medical School, Hannover, Lower Saxony, Germany; and Tobias Koenig, Jonas Neuser, Andreas Schaefer, Jochen Tillmans and Johann Bauersachs, Department of Cardiology and Angiology, Hannover Medical School, Hannover, Lower Saxony, Germany.

A new PET imaging tool can predict poor functional outcomes after a heart attack 68Ga-FAPI-46. According to research presented at the 2022 Society of Nuclear Medicine and Molecular Imaging Annual Meeting, when correlated with cardiac MRI 68Ga-FAPI-46 PET is a new specific indicator of active fibrosis and can identify a patient’s chances of recovery. The detailed presentation of 68Ga-FAPI-46 PET signal after acute anterior myocardial infarction was voted Image of the Year 2022 by SNMMI.

Each year, SNMMI selects an image that best illustrates the most promising advances in nuclear medicine and molecular imaging. The cutting-edge technologies captured in these images demonstrate the ability to improve patient care by detecting disease, aiding diagnosis, improving clinical confidence and providing tools to select appropriate treatments. This year, the SNMMI Henry N. Wagner, Jr. Image of the Year was selected from more than 1,000 abstracts submitted to the convention and voted for by reviewers and society leadership.

Acute myocardial infarction, commonly known as heart attack, is one of the leading causes of death worldwide. After a heart attack, the heart goes through a series of changes at the molecular and cellular levels. Fibroblast activation protein (FAP) is overexpressed in these changes and can provide useful information about a patient’s prognosis.

“Molecular PET imaging of fibroblast activation protein was recently evaluated in patients after acute myocardial infarction,” said Johanna Diekmann, MD, clinical scientist in the Department of Nuclear Medicine at Hannover Medical School in Hannover, Germany. “In our study, we attempted to gain further insights by correlating FAP-directed PET imaging with tissue characteristics from cardiac MRI and functional outcome.”

Thirty-five patients underwent 68Ga-FAPI-46 PET/CT, perfusion SPECT and cardiac MRI within 11 days of a heart attack. Cardiac FAP volume was determined by PET imaging and infarct size defined by SPECT imaging. Cardiac MRI showed functional parameters, area of ​​injury and tissue mapping. These data points were then collated to examine possible correlations.

In all patients, FAP upregulation was significantly greater than both infarct size and injury area as defined by SPECT and cardiac MRI, respectively. A higher degree of myocardial FAP upregulation was predictive of subsequent left ventricular dysfunction. The authors therefore concluded that fibroblast activation in non-infarcted areas of the heart may contribute to adverse outcomes.

“Myocardial infarction is an important factor in the development of heart failure, but the early molecular processes involved in the transition from initial injury to heart failure are poorly addressed,” Diekmann said. “New antifibrotic therapies (such as CAR-T cell therapies) could significantly transform the future therapy of heart failure. The use of FAPI-PET to select patients eligible for therapy would provide a new important application for PET in fibrosis and heart disease.” open.”

“FAPI is a very exciting radiotracer that holds great potential for the future of nuclear medicine and molecular imaging,” noted Heather Jacene, MD, Chair of SNMMI’s Scientific Program. “As the picture of the year shows, 68Ga-FAPI-46 PET/CT clearly indicates a profibrotic activity after acute myocardial infarction. The predictive value of FAPI-PET for the extent of subsequent decline in global cardiac function, if further validated, may in the future be used to select the most appropriate patients for antifibrotic therapies currently under development. This could ultimately have a powerful impact on cardiovascular medicine.”


New radiotracer offers opportunities for earlier intervention after heart attack


More information:
Conference: am.snmmi.org/iMIS/SNMMI-AM

Provided by the Society for Nuclear Medicine and Molecular Imaging

Citation: New Biomarker Predicts Severity of Heart Remodeling After Myocardial Infarction (2022 June 15) Retrieved June 22, 2022 from https://medicalxpress.com/news/2022-06-biomarker-severity-cardiac-remodeling-heart.html

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