Diagnostic Value of Relative Flow Reserve in Patients With Prior Coronary Artery Disease: A Post Hoc Analysis of the PACIFIC-2 Trial.

Background: The relative flow reserve (RFR) derived from quantitative myocardial perfusion imaging is the ratio of absolute myocardial perfusion in a stenotic to normally perfused area and is considered the noninvasive equivalent of fractional flow reserve (FFR). In patients with prior coronary artery disease (CAD), detecting hemodynamically significant CAD using hyperemic myocardial blood flow (hMBF) is complicated by diffuse CAD and microvascular disease. In these patients, RFR may improve the diagnostic performance of myocardial perfusion imaging.

Derivation and validation of an artificial intelligence-based plaque burden safety cut-off for long-term acute coronary syndrome from coronary computed tomography angiography.

Aims: Artificial intelligence (AI) has enabled accurate and fast plaque quantification from coronary computed tomography angiography (CCTA). However, AI detects any coronary plaque in up to 97% of patients. To avoid overdiagnosis, a plaque burden safety cut-off for future coronary events is needed.

The Impact of Hydrostatic Pressure on Fractional Flow Reserve in Saphenous Vein Grafts.

Background: The relationship between height differences related to graft anatomy and physiological pressure indices in coronary bypass grafts has not been studied. We sought to study the impact of hydrostatic pressure on fractional flow reserve (FFR) in saphenous vein grafts (SVGs).

Methods: Included were 66 symptomatic patients (76 SVGs) with prior coronary artery bypass grafting who underwent coronary computed tomography angiography (CCTA) preceding invasive coronary angiography with FFR interrogation of ≥ 1 SVGs.

CCTA-Derived coronary plaque burden offers enhanced prognostic value over CAC scoring in suspected CAD patients.

Aims: To assess the prognostic utility of coronary artery calcium (CAC) scoring and coronary computed tomography angiography (CCTA)-derived quantitative plaque metrics for predicting adverse cardiovascular outcomes.

Methods And Results: The study enrolled 2404 patients with suspected coronary artery disease (CAD) but without a prior history of CAD. All participants underwent CAC scoring and CCTA, with plaque metrics quantified using an artificial intelligence (AI)-based tool (Cleerly, Inc).

Homogeneity of the coronary microcirculation in angina with non-obstructive coronary artery disease.

Aims: The homogeneity of coronary microvascular dysfunction (CMD) across different myocardial territories in angina with non-obstructive coronary artery disease (ANOCA) patients is scarcely explored. This study investigates the variability in microvascular resistance reserve (MRR) across the 3 main perfusion territories of the coronary circulation to investigate the homogeneity or dishomogeneity of microcirculatory function.

Methods And Results: This post hoc analysis of the PACIFIC trials included symptomatic ANOCA patients with [15O]H2O positron emission tomography (PET) and three-vessel invasive fractional flow reserve (FFR).

Myocardial perfusion imaging in advanced coronary artery disease.

Myocardial perfusion imaging (MPI) is widely adapted as a noninvasive technique to assess the presence and extent of ischemia in patients with symptoms suggestive of obstructive coronary artery disease (CAD). However, as CAD advances, several factors can complicate the interpretation of MPI, subsequently impacting clinical decision-making. This review focuses on the utility of MPI by means of cardiac magnetic resonance (CMR) imaging, single-photon emission computed tomography (SPECT) and positron emission tomography (PET) in patients with advanced CAD-the latter characterized by documented CAD (i.

Comparison of Fractional Flow Reserve and Myocardial Perfusion Imaging in Saphenous Vein Grafts.

Background: Revascularization decision-making for saphenous vein grafts (SVGs) relies on angiographic lesion severity estimation, as studies on fractional flow reserve (FFR) for detecting ischemia in SVGs are scarce.

Aims: To compare FFR and quantitative coronary angiography (QCA) of SVGs against myocardial perfusion imaging (MPI) and to establish an optimal FFR threshold for SVGs.

Methods: This cross-sectional registry study included symptomatic patients with prior coronary artery bypass grafting who underwent single-photon emission computed tomography, positron emission tomography, or stress perfusion cardiac magnetic resonance imaging and had FFR measurements of ≥ 1 SVGs.

Impact of myocardial scar burden on microvascular resistance reserve in patients with coronary artery disease.

Purpose: The impact of myocardial scar on coronary microcirculation is not well understood. This study aims to evaluate the association between microvascular resistance reserve (MRR) and scar tissue.

Methods: In this post-hoc analysis of the PACIFIC 2 trial, symptomatic patients with prior myocardial infarction (MI) and/or percutaneous coronary intervention (PCI) underwent [O]HO positron emission tomography (PET), cardiac magnetic resonance (CMR) imaging, and fractional flow reserve (FFR).

Fractional Flow Reserve Relates Stronger to Coronary Plaque Burden Than Nonhyperemic Pressure Indexes.

Background: The relationship between fractional flow reserve (FFR), resting full-cycle ratio (RFR), instantaneous wave-free ratio (iFR), resting distal pressure/aortic pressure (Pd/Pa), and plaque burden as well as phenotype requires further elucidation.

Methods And Results: In this single-center cohort study, patients with suspected coronary artery disease who underwent invasive coronary angiography, including routine hyperemic (FFR) and nonhyperemic invasive pressure (Pd/Pa and iFR or RFR) interrogation and computed coronary tomography angiography were prospectively enrolled. Computed coronary tomography angiography was used to assess percentage atheroma volume (PAV), positive remodeling, and low-attenuation plaque.

Evaluation and clinical applicability of angiography-derived assessment of coronary microcirculatory resistance: a [O]HO PET study.

The introduction of wire-free microcirculatory resistance index from functional angiography (angio-IMR) promises swift detection of coronary microvascular dysfunction, however it has not been properly validated. We sought to validate angio-IMR against invasive IMR and PET derived microvascular resistance (MVR). Moreover, we studied if angio-IMR could aid in the detection of ischemia with non-obstructive coronary arteries (INOCA).

Microvascular resistance reserve in relation to total and vessel-specific atherosclerotic burden.

Aims: The relationship between coronary artery atherosclerosis and microvascular resistance remains unclear. This study aims to clarify the relationship between total atherosclerotic and vessel-specific atherosclerotic burden and microvascular resistance reserve (MRR).

Methods And Results: In this post hoc analysis of the PACIFIC 1 trial, symptomatic patients without prior coronary artery disease (CAD) underwent [15O]H2O positron emission tomography, coronary computed tomography angiography (CCTA), and invasive fractional flow reserve (FFR).

Correlation and Agreement of Quantitative Flow Ratio With Fractional Flow Reserve in Saphenous Vein Grafts.

Background: The applicability of quantitative flow ratio (QFR), a nonhyperemic, invasive coronary angiography-derived computation of fractional flow reserve (FFR), has not been studied in coronary artery bypass grafts. We sought to explore the correlation and diagnostic agreement between QFR and FFR in saphenous vein grafts (SVGs).

Methods And Results: A total of 129 prospectively included patients (mean age 73±8 years, 84% male) with prior coronary artery bypass grafting underwent invasive coronary angiography and pressure-derived functional assessment in 150 nonoccluded SVGs.

The effect of hydrostatic pressure on invasive coronary pressure measurements: Comparison with [O]HO-positron emission tomography flow data.

Background: Fractional flow reserve (FFR) has emerged as the invasive gold standard for assessing vessel-specific ischemia. However, FFR measurements are influenced by the hydrostatic effect, which might adversely impact the assessment of ischemia.

Aims: This study aimed to investigate the impact of hydrostatic pressure on FFR measurements by correcting for the height and comparing FFR with [O]HO positron emission tomography (PET)-derived relative flow reserve (RFR).

Diagnostic accuracy of non-invasive cardiac imaging modalities in patients with a history of coronary artery disease: a meta-analysis.

Background: The diagnostic performance of non-invasive imaging techniques for detecting obstructive coronary artery disease (CAD) in patients with a history of myocardial infarction or percutaneous coronary intervention has not been comprehensively evaluated. This meta-analysis assesses the diagnostic value of coronary CT angiography (CCTA), CCTA combined with CT perfusion (CCTA+CTP), cardiac MRI (CMR) and single-photon emission CT (SPECT) compared with invasive reference standards.

Methods: We systematically searched PubMed, Embase, Web of Science and the Cochrane Library from 2005 to September 2022 for prospective, blinded studies including populations with ≥50% prior CAD.

Location-specific prognostic significance of plaque burden, stenosis, and plaque morphology in coronary artery disease.

Aims: To investigate the location-specific prognostic significance of plaque burden, diameter stenosis, and plaque morphology.

Methods And Results: Patients without a documented cardiac history that underwent coronary computed tomography angiography (CCTA) for suspected coronary artery disease were included. Percentage atheroma volume (PAV), maximum diameter stenosis, and plaque morphology were assessed and classified into proximal, mid, or distal segments of the coronary tree.

PET myocardial perfusion imaging: Trends, challenges, and opportunities.

Various non-invasive images are used in clinical practice for the diagnosis and prognostication of chronic coronary syndromes. Notably, quantitative myocardial perfusion imaging (MPI) through positron emission tomography (PET) has seen significant technical advancements and a substantial increase in its use over the past two decades. This progress has generated an unprecedented wealth of clinical information, which, when properly applied, can diagnose and fine-tune the management of patients with different types of ischemic syndromes.