Positron emission tomography for phenotyping inflammation of cardiovascular diseases

Inflammatory processes play a central role in the development and complications of cardiovascular diseases (CVDs), profoundly affecting the severity and prognosis of these events. However, the current tools used to measure inflammation have some limitations. Blood biomarkers cannot pinpoint the location of inflammation and are vulnerable to various factors. Histological assessments ex vivo cannot accurately reflect the full dynamic picture of pathophysiology. The rapid development of positron emission tomography (PET) imaging not only enhances our understanding of biological processes in vivo but also contributes significantly to clinical management as a non-invasive biomarker. This review summarizes the PET imaging of key immune cell responses in CVDs, including immune cell metabolism, ligand/receptor interactions, and enzyme secretion, and discusses emerging opportunities and challenges in PET imaging-based inflammatory phenotyping and future perspectives. Advantages of PET imaging of CVDs in clinical practice. PET radiotracers targeting specific cell types in cardiovascular inflammation serve as phenotypic biomarkers. PET imaging offers translational value (safe clinical translation in patients), diagnostic value (high target-to-background ratios), therapeutic value (selecting appropriate patients for immunotherapy and monitoring therapy response), and predictive value (good correlation between radiotracer uptake and disease progression). • CVDs cause serious global concern and present different clinical manifestations, disease prognosis and therapeutic strategies. • Inflammation is universally recognized as a fundamental and shared mechanism at all stages of CVDs. • PET imaging has been used to monitor pathological processes, provide prognosis prediction and therapeutic strategies for CVDs. • We summarize PET imaging of key immune responses (immunometabolism, ligand/receptor interactions and enzyme secretion) in CVDs. • Challenges and future perspectives of PET imaging for phenotyping inflammatory are discussed to expedite its development.