Publications by authors named "Hiroyuki Omori"

Background: The angiography-derived non-hyperemic pressure ratio (angioNHPR) is a novel index of NHPR based on artificial intelligence (AI) that does not require pressure wires. We investigated the diagnostic accuracy of angioNHPR for detecting hemodynamically relevant coronary artery disease.

Methods And Results: In this retrospective single-center study, angioNHPR was assessed using the invasive NHPR as the reference standard.

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Background: To prevent excessive compression of the cortical layer, which can lead to marginal bone loss, various companies have introduced specialized drills. However, these drills often lack the necessary precision, as the operator's hand may neither be stable enough to prevent ovalization and over-widening nor precise enough to maintain coaxial alignment. Therefore, the aim of this study was to develop a device capable of achieving calibrated cortical preparation in terms of both dimension and coaxiality.

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Article Synopsis
  • AI-QCT (Artificial Intelligence Quantitative CT) is effective for identifying coronary plaque morphology, specifically low-density noncalcified plaque (LD-NCP), utilizing NIRS-IVUS (near-infrared spectroscopy-intravascular ultrasound) as a benchmark.
  • The study assessed 133 plaques from 47 patients, revealing AI-QCT's high accuracy (94%) and a strong correlation with IVUS metrics such as vessel area and plaque burden.
  • Results suggest that AI-QCT is a reliable tool for detecting significant LD-NCP, with a notable optimal volume threshold identified for improved diagnostic performance.
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There have been no studies comparing clinical outcomes of physiology-guided revascularization in patients with unprotected left main coronary disease (ULMD) between percutaneous coronary intervention (PCI) vs. coronary artery bypass grafting (CABG). The aim of this study was to assess the long-term clinical outcomes between PCI and CABG of patients with physiologically significant ULMD.

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  • Angiographic fractional flow reserve (angioFFR) is an AI-driven tool used to assess coronary artery disease by analyzing angiograms and calculating fractional flow reserve.
  • In a study involving 200 patients with significant stenoses, angioFFR demonstrated an accuracy of 87.7%, with a sensitivity of 76.8% and specificity of 94.3%, when compared to invasive FFR measurements.
  • The results indicated that angioFFR correlates well with invasive FFR, showing similar gradients in pre-stenting segments, highlighting its potential utility in clinical settings.
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  • Coronary artery bifurcation lesions are challenging and often lead to complicated procedures and poorer outcomes compared to non-bifurcation lesions during cardiac catheterization.
  • *A thorough anatomical and physiological assessment of these lesions is crucial before, during, and after intervention to understand their impact on blood flow and to make informed treatment decisions.
  • *This consensus document from Korean, Japanese, and European experts outlines the importance of a physiological approach, offering guidance, potential challenges, and future strategies for treating coronary bifurcation lesions.*
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Background The FiGARO (FFR versus iFR in Assessment of Hemodynamic Lesion Significance, and an Explanation of Their Discrepancies) trial is a prospective registry searching for predictors of fractional flow reserve/instantaneous wave-free ratio (FFR/iFR) discrepancy. Methods and Results FFR/iFR were analyzed using a Verrata wire, and coronary flow reserve was analyzed using a Combomap machine (both Philips-Volcano). The risk polymorphisms for endothelial nitric oxide synthase and for heme oxygenase-1 were analyzed.

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Background: Myocardial perfusion imaging (MPI) and fractional flow reserve (FFR) are established approaches to the assessment of myocardial ischemia. Recently, various FFR cutoff values were proposed, but the diagnostic accuracy of MPI in identifying positive FFR using various cutoff values is not well established.

Methods and results: We retrospectively studied 273 patients who underwent stress MPI and FFR within a 3-month period.

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Cells have a regulatory mechanism known as heat shock (HS) response, which induces the expression of HS genes and proteins in response to heat and other cellular stresses. Exposure to moderate HS results in beneficial effects, such as thermotolerance and promotes survival, whereas excessive HS causes cell death. The effect of HS on cells depends on both exogenous factors, including the temperature and duration of heat application, and endogenous factors, such as the degree of cell differentiation.

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Aims: This study aimed to determine the effects of a proprotein convertase subtilisin-kexin type 9 inhibitor (PCSK9i) on coronary plaque volume and lipid components in patients with a history of coronary artery disease (CAD).

Methods And Results: This prospective, open-label, single-centre study analysed non-culprit coronary segments using near-infrared spectroscopy-intravascular ultrasound (NIRS-IVUS) at baseline and follow-up angiography. Following changes in the lipid-lowering treatment based on the most recent guideline, the enrolled subjects were divided into two groups: treatment with PCSK9i and statins (PCSK9i: 21 patients and 40 segments) and statins only (control: 32 patients and 50 segments).

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Article Synopsis
  • - The study aimed to evaluate how accurately pre-percutaneous coronary intervention (PCI) predicted nonhyperemic pressure ratios (NHPRs) correspond to actual NHPRs measured after PCI, while also examining the effectiveness of using pre-PCI NHPR assessments for guiding treatment.
  • - Researchers conducted a multicenter trial comparing three NHPR measuring methods—instantaneous wave-free ratio (iFR), resting full-cycle ratio (RFR), and diastolic pressure ratio (dPR)—to see how well they predict functional outcomes post-PCI.
  • - Results showed strong correlations between predicted and actual NHPRs for all three methods, and the NHPR pullback strategy resulted in fewer and shorter treated lesions compared to traditional angiography-guid
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  • Recent recommendations suggest measuring fractional flow reserve (FFR) values 1-2 cm distal to stenosis in coronary CTA for better accuracy in diagnosing ischemia, as far distal measurements may lead to overestimation.
  • A study evaluated the diagnostic performance of FFR values taken at 1-2 cm distal to stenosis and further down the artery, comparing them against invasive FFR across 365 vessels in 253 patients.
  • Results showed that FFR values measured 1-2 cm distal to stenosis had a higher diagnostic accuracy (AUC of 0.85) compared to far distal segment measurements (AUC of 0.80), with improved sensitivity, specificity, and positive predictive value in various coronary artery
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Background: Identifying the individual hemodynamic significance of tandem coronary artery lesions can be complicated by the crosstalk phenomenon which occurs between serial stenoses under hyperemic conditions. Physiological assessments performed under resting conditions are considered to be, theoretically, less affected by the hemodynamic interaction between serial coronary stenoses. The purpose of this study was to assess whether pressure-wire (PW) pullback measurements at rest and during hyperemia provided different information as to which stenosis appeared to be most functionally significant.

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Background: The per-vessel level impact of physiological pattern of disease on the discordance between fractional flow reserve (FFR) and instantaneous wave-free ratio (iFR) has not been clarified.

Methods and results: Using the AJIP registry, vessels with FFR/iFR discordance (133/671 [19.8%]) were analyzed.

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The diastolic pressure ratio (dPR) and resting full-cycle ratio (RFR) are considered to be almost identical to the instantaneous wave-free ratio (iFR) in the retrospective analysis of pooled data. The aim of this study was to investigate the direct comparison of iFR and these new resting indexes in real world practice. Two pressure wires were inserted and placed in the distal part of the same coronary artery.

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Objectives: The aim of this study was to compare diagnostic performance between quantitative flow ratio (QFR) derived from coronary angiography and fractional flow reserve derived from computed tomography (FFR) using fractional flow reserve (FFR) as the reference standard.

Background: QFR and FFR are recently developed, less invasive techniques for functional assessment of coronary artery disease.

Methods: QFR, FFR, and FFR were measured in 152 patients (233 vessels) with stable coronary artery disease.

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The roles of epidermal growth factor (EGF) in the regulation of prolactin (PRL) gene expression in the normal pituitary gland remain poorly understood. In the present study, the effects of EGF and an inhibitor of the EGF receptor, erlotinib, on PRL gene expression were examined both in the pituitary tumour cell line GH3 and in a primary culture of the mouse pituitary gland under similar experimental conditions. The results showed that EGF stimulated PRL expression in GH3 cells, but not in normal cells.

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We tested whether the level of endothelial dysfunction assessed by digital tonometry, and expressed as reactive hyperemia index (RHI), is related to occurrences of a discrepancy between fractional flow reserve (FFR) and the instantaneous wave free ratio (iFR) (ClinicalTrials.gov identifier: NCT03033810). We examined patients with coronary stenosis in the range of 40-70%, assessed by both FFR and iFR (system Philips-Volcano) for stable angina.

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Objectives: The objective was to evaluate the safety, feasibility, and accuracy of the jailed-pressure wire technique using a durable optical fiber-based pressure wire with high-pressure dilatation using a non-compliant balloon after main vessel stenting.

Background: Fractional flow reserve (FFR) information can help interventionists determine whether they should treat a jailed-side branch (SB). However, re-crossing a pressure wire into a jailed-SB is sometimes technically difficult.

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Article Synopsis
  • This study compared the effectiveness of two myocardial perfusion imaging (MPI) protocols, Tc/Tc and SDI, in diagnosing coronary artery issues among 147 patients who also underwent coronary angiography.
  • The SDI protocol showed significantly better sensitivity (89%) and accuracy (85%) compared to the Tc/Tc protocol, which had a sensitivity of 56% and accuracy of 69%.
  • Overall, the findings suggest that the SDI protocol is more reliable for detecting coronary ischemia compared to the traditional Tc/Tc method.
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Background: Postocclusional hyperemia caused by balloon occlusion is a potential alternative method of inducing hyperemia for measuring post-percutaneous coronary intervention fractional flow reserve (FFR). The aim of this study was to investigate postocclusional hyperemia as a method of inducing hyperemia.

Methods And Results: FFR measured by postocclusional hyperemia (FFRoccl) caused by balloon occlusion after percutaneous coronary intervention was compared with FFR measured by drug-induced hyperemia (FFR measured by intravenous ATP; and FFR measured by intracoronary papaverine injection [FFRpap]) in 98 lesions from 98 patients.

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