Molecular Imaging in Ischemic Heart Disease

Abstract

Purpose of Review The purpose of this paper is to review current and new modalities to image key biological processes in ischemic heart disease and after myocardial infarction non-invasively. Recent Findings New imaging targets have been developed to detect and quantify myocardial damage after ischemia. Although positron emission tomography (PET) has been leading the development of new probes in the past, continuous improvements of magnetic resonance imaging (MRI) together with the development of new novel MRI contrast agents opens new research avenues including the combination of both PET and MRI to obtain anatomic, functional, and molecular information simultaneously, which is not possible from a single imaging session. Summary This review summarizes the state of art of non-invasive molecular imaging of the myocardium during ischemia and after myocardial infarction using PET and MRI. We also describe the different contrast agents that have been developed to image the different phases of cardiac healing and the biological processes associated with each of those phases. Importantly, here we focus on imaging of inflammation as it is the key biological process that orchestrates clearance of dead cells, tissue remodeling, cardiac repair, and future outcome. We also focus on clinical translation of some of the novel contrast agents that have been tested in patients and discuss the need for larger, multi-center patient studies to fully validate the applicability of new imaging probes.

Unraveling the Complexity: From Molecular Subtypes to Therapeutic Strategies in Heart Failure with Preserved Ejection Fraction and Atrial Fibrillation

“…What makes these imaging sidekicks truly special is their ability to play it cool without any invasive measures. Theyʹre like the heartʹs personal photographers, capturing snapshots of the damage, keeping an eye on tissue makeover, and documenting the heartʹs journey to recovery [106]. Imagine them as the paparazzi of the medical world, but with a heartwarming mission.PET imaging deserves its own spotlight as the storyteller extraordinaire.…”

Emerging role of melatonin in the alleviation of ischemic heart disease: A comprehensive review

“…In response to the coronary impediment, part of the cardiomyocytes die, generating a milieu that stimulates an invasion of inflammatory phagocytes like neutrophils shortly after the event, subsequently accompanied by an infiltration of reparative and inflammatory monocytes. 58,59 Inflammation is essential in cardiac healing because it eliminates dead cells and activates cells that are crucial for the healing process, including the generation of extracellular matrix proteins, which develop into a vital component of the scar tissue that replaces the dead cardiomyocytes. 60 Nevertheless, if the inflammatory response is not balanced, it can have a negative impact on heart repair, resulting in hypertrophy, ventricular dilation, or a decrease of the myocardium, among other outcomes, a phenomenon that is referred to as adverse ventricular remodeling.…”

“…Patients who have adverse ventricular remodeling are more likely to experience progressive heart failure and the accompanying poor prognosis. 58,61,62 Necrotic cell death also induces a pro-inflammatory response during acute myocardial ischemia via numerous processes, comprising complement cascade activation, ROS generation, and the release of damage-associated molecular patterns (DAMPs). DAMPs cause cardiomyocyte death by interacting to Toll-like receptors (TLRs), luring leukocytes to the infarct zone, and stimulating the release of several proinflammatory cytokines.…”

Interventional real-time molecular MRI allows diagnostic targeting of early myocardial injury in a pig model of ischemia and reperfusion

“…11,12 Previously, molecular MRI has successfully been used in several small animal models targeting diverse receptors of the in ammatory cascade of atherothrombotic disease including cell adhesion molecules. [13][14][15] With increasing appreciation of the role of in ammation in human cardiovascular disease 16 , methods would be highly desirable that combine the standard assessment of edema and brosis with molecular imaging of in ammatory targets in a hybrid imaging approach. So far, transition of this concept to a larger model or the patient has been restricted to nuclear imaging due to challenges with sensitivity.…”