Cardiac nuclear imaging workforce: Trends from Medicare Part B (2013-2022).

Background: Cardiac positron emission tomography (PET) and single-photon emission computed tomography (SPECT) are widely used for the assessment of coronary artery disease. While SPECT remains more available, workforce shortages and training demands contribute to geographic disparities in PET availability, impacting patient access to advanced imaging. Therefore, we assessed trends in the U.

Prognostic Value of PET-Derived Myocardial Flow Reserve in Patients With Very High Coronary Artery Calcium Score.

Background: Coronary artery calcium (CAC) is a strong predictor of cardiovascular outcomes, with patients having high CAC experiencing event rates similar to those in secondary prevention populations. Emerging evidence suggests that patients with extremely high CAC (≥1000) represent a distinct high-risk group. Therefore, this study aims to evaluate the prognostic value of myocardial flow reserve (MFR) in patients with very high CAC.

Cardiac CT and PET for Surveillance of Heart Transplant Recipients: Systematic Review and Bayesian Meta-Analysis.

Background: For noninvasive surveillance of cardiac allograft vasculopathy (CAV), cardiac computed tomography (cardiac computed tomography [CT]) and positron emission tomography (PET) received a Class IIa recommendation by the 2023 ISHLT (International Society for Heart and Lung Transplantation) guidelines. However, implementation has lagged behind because of concerns about their ability to rule out disease and stratify risk.

Objectives: The purpose of this study was to define the diagnostic and prognostic ability of PET and cardiac CT in cardiac transplant recipients.

Artificial intelligence-enabled electrocardiography and echocardiography to track preclinical progression of transthyretin amyloid cardiomyopathy.

Background And Aims: The diagnosis of transthyretin amyloid cardiomyopathy (ATTR-CM) requires advanced imaging, precluding large-scale preclinical testing. Artificial intelligence (AI)-enabled transthoracic echocardiography (TTE) and electrocardiography (ECG) may provide a scalable strategy for preclinical monitoring.

Methods: This was a retrospective analysis of individuals referred for nuclear cardiac amyloid testing at the Yale-New Haven Health System (YNHHS, internal cohort) and Houston Methodist Hospitals (HMH, external cohort).

AI-Derived Splenic Response in Cardiac PET Predicts Mortality: A Multi-Site Study.

Background: Inadequate pharmacologic stress may limit the diagnostic and prognostic accuracy of myocardial perfusion imaging (MPI). The splenic ratio (SR), a measure of stress adequacy, has emerged as a potential imaging biomarker.

Objectives: To evaluate the prognostic value of artificial intelligence (AI)-derived SR in a large multicenter Rb-PET cohort undergoing regadenoson stress testing.

Geographical distribution and accessibility to cardiac CT readers in the United States: A snapshot from the 2022 medicare analysis.

Background: Cardiac computed tomography (CCT) is an increasingly important modality for the diagnosis and management of cardiovascular diseases. However, disparities in the availability of trained CCT readers across the United States limit equal access.

Objective: This study examined the geographical distribution and characteristics of CCT readers who billed Medicare for CCT in 2022.

Utility of 18F-Flurpiridaz PET Relative Flow Reserve in Differentiating Obstructive from Nonobstructive Coronary Artery Disease.

Background: Absolute quantification of myocardial blood flow (MBF) on PET perfusion imaging improves the identification of coronary artery disease (CAD). However, distinguishing MBF impairment due to obstructive CAD from nonobstructive CAD remains challenging. We aimed to evaluate the incremental diagnostic value of PET-derived relative flow reserve (RFR) in the diagnosis of obstructive CAD.

Pericoronary Adipose Tissue Attenuation in Patients with Future Acute Coronary Syndromes: The ICONIC Study.

Purpose Pericoronary adipose tissue attenuation (PCATa) measured at coronary CT angiography (CCTA) is an imaging biomarker of coronary inflammation associated with long-term adverse cardiac events. The authors hypothesized that PCATa may independently identify patients at risk for acute coronary syndromes (ACS). Materials and Methods The authors performed a retrospective substudy of the Incident Coronary Syndromes Identified by Computed Tomography (ICONIC) study, a propensity-matched case-control study of patients with CCTA followed by ACS.

Comparison of PET-CT and CZT-SPECT on myocardial blood flow and flow reserve measurement: A systematic review and meta-analysis.

Background: Myocardial blood flow (MBF) and myocardial flow reserve (MFR) measurement is crucial for diagnosing and managing coronary artery disease and microvascular dysfunction. While positron emission tomography (PET) is the gold standard, cadmium zinc telluride (CZT) is more accessible. This systematic review and meta-analysis aim to compare the accuracy, and the systematic bias of MBF and MFR measurement using CZT compared with PET.

Temporal trends and geographic accessibility to cardiac magnetic resonance readers across the United States: an analysis of Medicare Part B data.

Background: Cardiovascular magnetic resonance (CMR) has a growing role in the diagnosis and management of cardiac disease. However, there is little recent data on the availability of CMR physicians (readers) in the United States (US).

Objective: To demonstrate the geographic proximity and accessibility of patients to CMR services and CMR physicians across the US.

The impact of attenuation correction and prone positioning on stress-only imaging in cardiac SPECT: An observational study.

Background: Current guidelines recommend stress-only single photon emission computed tomography myocardial perfusion imaging (SPECT MPI) in select patients to reduce time, cost, and radiation. However, stress-only imaging remains underutilized.

Objectives: We assessed techniques to increase the adoption of stress-only SPECT MPI, specifically evaluating whether prone positioning and CT-based attenuation correction (AC) reduce the need for additional rest imaging.

Cardiac positron emission tomography/Computed tomography (PET/CT) in current cardiology guidelines.

Cardiac positron emission tomography (PET) is increasingly utilized in clinical practice. This review examines the latest clinical practice guidelines from the American College of Cardiology/American Heart Association (ACC/AHA), the European Society of Cardiology (ESC), the International Society for Heart and Lung Transplantation (ISHLT), and multisocietal consensus statements as of December 2024, to assess the extent to which cardiac PET is incorporated into their recommendations.

The prognostic interplay between PET-derived resting myocardial blood flow and left ventricular ejection fraction.

Aims: Whether the prognostic value of resting myocardial blood flow (MBFrest) and myocardial flow reserve (MFR) is modified by a patient's ejection fraction (EF) has not been studied.

Methods And Results: Consecutive patients undergoing stress/rest MPI using Rb-82 PET between 2019 and 2024 were included. The primary outcome was a composite of death and heart failure (HF) hospitalizations.

The prognostic significance of rate pressure product corrected myocardial flow reserve.

Background: It is unknown whether myocardial flow reserve (MFR) corrected for rate pressure product (RPP) can risk stratify events when added to uncorrected MFR. In this study, we evaluated the relationship between concordant vs discordant corrected and uncorrected MFR and incident outcomes.

Methods: Consecutive patients referred for clinically indicated positron emission tomography were enrolled in a prospective registry.

Myocardial flow reserve and resting contractility modulate the impact of contractile reserve in patients undergoing rubidum-82 positron emission tomography.

Although ejection fraction reserve (EFR) harbors prognostic value in patients undergoing positron emission tomography (PET) myocardial perfusion imaging (MPI), whether resting EF and myocardial flow reserve (MFR) modulate its prognostic value has not been studied. Consecutive patients undergoing stress/rest MPI using Rb-82 PET between 2019 and 2024 were included. The primary outcome was a composite of death and heart failure (HF) hospitalizations.

Advanced cardiac imaging modalities in U.S. heart transplant centers: availability and distribution.

Purpose: This study evaluates the availability of advanced imaging modalities, including cardiac computed tomography (CCT), cardiac magnetic resonance (CMR), cardiac positron emission tomography (PET), and intravascular ultrasound (IVUS)/optical coherence tomography (OCT), at Medicare-approved heart transplant centers across the United States.

Methods: We retrieved the list of Medicare-approved heart transplant centers and data on physicians billing for cardiac imaging procedures from the CMS website. Addresses of billing physicians were matched with those of heart transplant centers to determine the availability of imaging modalities at each center.

The impact of obesity on myocardial flow reserve and its prognostic utility.

Background: Obesity is a major cardiovascular risk factor associated with coronary microvascular dysfunction, which can be noninvasively assessed using myocardial flow reserve (MFR) on positron emission tomography (PET). As impaired MFR identifies high-risk patients, we assessed whether body mass index (BMI) modifies the association between MFR and cardiovascular outcomes.

Methods: Consecutive patients with no known coronary artery disease who had a clinically indicated PET were enrolled and followed prospectively for incident outcomes (all-cause death, major adverse cardiovascular events (MACE), and heart failure admissions).