The Updated Registry of Fast Myocardial Perfusion Imaging with Next-Generation SPECT (REFINE SPECT 2.0).

The Registry of Fast Myocardial Perfusion Imaging with Next-Generation SPECT (REFINE SPECT) has been expanded to include more patients and CT attenuation correction imaging. We present the design and initial results from the updated registry. The updated REFINE SPECT is a multicenter, international registry with clinical data and image files.

Functional Status and Quality of Life in Light-Chain Amyloidosis: Advanced Imaging, Longitudinal Changes, and Outcomes.

Background: In light-chain (AL) amyloidosis, whether functional status and heart failure-related quality of life (HF-QOL) correlate with cardiomyopathy severity, improve with therapy, and are associated with major adverse cardiac events (MACE) beyond validated scores is not well-known.

Objectives: The authors aimed to: 1) correlate functional status and HF-QOL with cardiomyopathy severity; 2) analyze their longitudinal changes; and 3) assess their independent associations with MACE.

Methods: This study included 106 participants with AL amyloidosis, with 81% having AL cardiomyopathy.

Relationship of Subendocardial Perfusion to Myocardial Injury, Cardiac Structure, and Clinical Outcomes Among Patients With Hypertension.

Background: Coronary microvascular dysfunction has been implicated in the development of hypertensive heart disease and heart failure, with subendocardial ischemia identified as a driver of sustained myocardial injury and fibrosis. We aimed to evaluate the relationships of subendocardial perfusion with cardiac injury, structure, and a composite of major adverse cardiac and cerebrovascular events consisting of death, heart failure hospitalization, myocardial infarction, and stroke.

Methods: Layer-specific blood flow and myocardial flow reserve (MFR; stress/rest myocardial blood flow) were assessed by N-ammonia perfusion positron emission tomography in consecutive patients with hypertension without flow-limiting coronary artery disease (summed stress score <3) imaged at Brigham and Women's Hospital (Boston, MA) from 2015 to 2021.

Recent Advances in Positron Emission Tomography Radiotracers to Image Cardiac Amyloidosis.

Cardiac amyloidosis includes a group of protein-misfolding diseases characterized by fibril accumulation within the extracellular space of the myocardium and cardiac dysfunction. Cardiac amyloidosis has high mortality. Emerging radionuclide techniques have helped us to better understand disease pathogenesis, prognostication, and treatment response in cardiac amyloidosis.

Quantitative Tc-pyrophosphate myocardial uptake: Changes on transthyretin stabilization therapy.

Background: Quantitative technetium-99m-pyrophosphate cardiac single-photon emission computed tomography (Tc-PYP SPECT/CT) is an emerging method for estimating myocardial burden of transthyretin cardiac amyloidosis (ATTR-CA), but its efficacy in monitoring longitudinal changes remains uncertain. We aimed to investigate longitudinal changes in cardiac ATTR amyloid burden following transthyretin stabilization therapy using visual and quantitative Tc-PYP SPECT/CT and to relate these with changes in cardiac biomarkers and function.

Methods: This prospective longitudinal cohort study investigated changes in Tc-PYP SPECT/CT in 23 participants with ATTR-CA on transthyretin stabilization therapy (median: 2.

Myocardial Characteristics, Cardiac Structure, and Cardiac Function in Systemic Light-Chain Amyloidosis.

Background: In systemic light-chain (AL) amyloidosis, cardiac involvement portends poor outcomes.

Objectives: The authors' objectives were to detect early myocardial alterations, to analyze longitudinal changes with therapy, and to predict major adverse cardiac events (MACE) in participants with AL amyloidosis using cardiac magnetic resonance imaging (MRI).

Methods: Recently diagnosed participants were prospectively enrolled.

Prognostic Value of Left Ventricular F-Florbetapir Uptake in Systemic Light-Chain Amyloidosis.

Background: Positron emission tomography/computed tomography (PET/CT) with F-florbetapir, a novel amyloid-targeting radiotracer, can quantify left ventricular (LV) amyloid burden in systemic light-chain (AL) amyloidosis. However, its prognostic value is not known.

Objectives: The authors' aim was to evaluate the prognostic value of LV amyloid burden quantified by F-florbetapir PET/CT, and to identify mechanistic pathways mediating its association with outcomes.

Comparative effectiveness of positron emission tomography and single-photon emission computed tomography myocardial perfusion imaging for predicting risk in patients with cardiometabolic disease.

Background: The epidemiology of coronary artery disease (CAD) has shifted, with increasing prevalence of cardiometabolic disease and decreasing findings of obstructive CAD on myocardial perfusion imaging (MPI). Coronary microvascular dysfunction (CMD), defined as impaired myocardial flow reserve (MFR) by positron emission tomography (PET), has emerged as a key mediator of risk. We aimed to assess whether PET MFR provides additive value for risk stratification of cardiometabolic disease patients compared with single-photon emission computed tomography (SPECT) MPI.

Radionuclide Imaging of Cardiac Amyloidosis: An Update and Future Aspects.

Cardiac amyloidosis (CA) is caused by the misfolding, accumulation and aggregation of proteins into large fibrils in the extracellular compartment of the myocardium, leading to restrictive cardiomyopathy, heart failure and death. The major forms are transthyretin (ATTR) CA and light-chain (AL) CA, based on the respective precursor protein. Each of them requires early diagnosis for a timely treatment initiation that will improve patient outcomes.

Mechanisms of left ventricular systolic dysfunction in light chain amyloidosis: a multiparametric cardiac MRI study.

Background: Cardiac systolic dysfunction is a poor prognostic marker in light-chain (AL) cardiomyopathy, a primary interstitial disorder; however, its pathogenesis is poorly understood.

Purpose: This study aims to analyze the effects of extracellular volume (ECV) expansion, a surrogate marker of amyloid burden on myocardial blood flow (MBF), myocardial work efficiency (MWE), and left ventricular (LV) systolic dysfunction in AL amyloidosis.

Methods: Subjects with biopsy-proven AL amyloidosis were prospectively enrolled (April 2016-June 2021; Clinicaltrials.

Prognostic value of myocardial flow reserve vs corrected myocardial flow reserve in patients without obstructive coronary artery disease.

Background: Myocardial flow reserve (MFR) by positron emission tomography (PET) is a validated measure of cardiovascular risk. Elevated resting rate pressure product (RPP = heart rate x systolic blood pressure) can cause high resting myocardial blood flow (MBF), resulting in reduced MFR despite normal/near-normal peak stress MBF. When resting MBF is high, it is not known if RPP-corrected MFR (MFR) helps reclassify CV risk.

F-FDG PET/CT and radiolabeled leukocyte SPECT/CT imaging for the evaluation of cardiovascular infection in the multimodality context: ASNC Imaging Indications (ASNC I) Series Expert Consensus Recommendations from ASNC, AATS, ACC, AHA, ASE, EANM, HRS, IDSA, SCCT, SNMMI, and STS.

This document on cardiovascular infection, including infective endocarditis, is the first in the American Society of Nuclear Cardiology Imaging Indications (ASNC I) series to assess the role of radionuclide imaging in the multimodality context for the evaluation of complex systemic diseases with multi-societal involvement including pertinent disciplines. A rigorous modified Delphi approach was used to determine consensus clinical indications, diagnostic criteria, and an algorithmic approach to diagnosis of cardiovascular infection including infective endocarditis. Cardiovascular infection incidence is increasing and is associated with high morbidity and mortality.