Instantaneous wave free ratio

BACKGROUND/PURPOSE: To evaluate the impact of coronary artery disease (CAD), percutaneous coronary intervention (PCI), and coronary lesion complexity on outcomes of transcatheter aortic valve replacement (TAVR) for aortic stenosis. METHODS/MATERIALS: This retrospective study included 1042 patients divided into two groups by the presence or absence of CAD (SYNTAX score 0, no history of revascularization). Propensity score matching was used to compare the two groups...

Despite guideline-based recommendation of the interchangeable use of instantaneous wave-free ratio (iFR) and fractional flow reserve (FFR) to guide revascularization decision-making, iFR/FFR could demonstrate different physiological or clinical outcomes in some specific patient or lesion subsets. Therefore, we sought to investigate the impact of difference between iFR and FFR-guided revascularization decision-making on clinical outcomes in patients with left main disease (LMD). In this international multicenter registry of LMD with physiological interrogation, we identified 275 patients in whom physiological assessment was performed with both iFR/FFR...

The treatment of coronary artery disease (CAD) in patients with severe aortic valve stenosis (AVS) eligible for transcatheter aortic valve implantation (TAVI) is not supported by clinical evidence, and the role of physiology over anatomy as well as the timing of coronary intervention are not defined. FAITAVI (ClinicalTrials.gov: NCT03360591) is a nationwide prospective, open-label, multicentre, randomised controlled study comparing the angiography-guided versus the physiology-guided coronary revascularisation strategy in patients with combined significant CAD and severe AVS undergoing TAVI...

BACKGROUND: The optimal functional evaluation of coronary artery stenosis in patients with severe aortic stenosis (AS) has not been established. The objective of the study was to evaluate the instantaneous wave-free ratio (iFR) and fractional flow reserve (FFR) in patients with and without severe AS. METHODS: We retrospectively investigated 395 lesions in 293 patients with severe AS and 2257 lesions in 1882 patients without severe AS between 2010 and 2022 from a subgroup of the Interventional Cardiology Research In-Cooperation Society FFR Registry...

OBJECTIVES: The instantaneous wave-free ratio (iwFR) has limited availability. A new resting index called the constant-resistance ratio (cRR), which dynamically identifies cardiac intervals with constant and minimum resistance, has been developed; however, its diagnostic performance is unknown. The aim of this study was to validate the cRR by retrospectively calculating the cRR values from raw pressure waveforms of 2 publicly available datasets and compare them with those of the iwFR...

Background: Noninvasive imaging methods, either anatomical or functional tests, serve as essential instruments for the appropriate management of patients with established or suspected coronary artery disease (CAD). We sought to evaluate the safety and efficacy of a coronary computed tomography angiography (CCTA) plus stress cardiac magnetic resonance imaging (S-CMR) strategy in patients with chronic coronary syndrome (CCS). Methods: Patients with suspected CCS showing intermediate coronary plaques (stenosis 30-70%) at CCTA underwent S-CMR...

OBJECTIVE: Fractional flow reserve (FFR) and instantaneous wave-free ratio (iFR) are invasive methods to assess the functional significance of intermediate severity coronary lesions. Both indexes have been extensively validated in clinical trials in guiding revascularisation in patients with stable ischaemic heart disease undergoing percutaneous coronary intervention (PCI) with improved clinical outcomes. However, the role of these tools in coronary artery bypass grafting (CABG) is less clear...

BACKGROUND: The application of fractional flow reserve (FFR) and instantaneous wave-free ratio (iFR) in multivessel coronary artery disease (CAD) patients has not been definitively explored. We herein assessed how treatment strategies were decided based on FFR/iFR values in vessels selected clinically. Specifically, we sought to determine whether treatment selection was based on whether the vessel tested was the clinical target stenosis. METHODS: 270 consecutive patients with angiographically determined multivessel disease who underwent FFR/iFR testing were included...

Homeostatic, circadian and ultradian mechanisms play crucial roles in the regulation of sleep. Evidence suggests that ratios of low-to-high frequency power in the electroencephalogram (EEG) spectrum indicate the instantaneous level of sleep pressure, influenced by factors such as individual sleep-wake history, current sleep stage, age-related differences and brain topography characteristics. These effects are well captured and reflected in the spectral exponent, a composite measure of the constant low-to-high frequency ratio in the periodogram, which is scale-free and exhibits lower interindividual variability compared to slow wave activity, potentially serving as a suitable standardization and reference measure...

OBJECTIVES: Coronary angiography (CAG)-derived physiology methods have been developed in an attempt to simplify and increase the usage of coronary physiology, based mostly on dynamic fluid computational algorithms. We aimed to develop a different approach based on artificial intelligence methods, which has seldom been explored. METHODS: Consecutive patients undergoing invasive instantaneous free-wave ratio (iFR) measurements were included. We developed artificial intelligence (AI) models capable of classifying target lesions as positive (iFR ≤ 0...

Fractional flow reserve (FFR) and instantaneous wave-free ratio (iFR) are invasive techniques used to evaluate the hemodynamic significance of coronary artery stenosis. These methods have been validated through perfusion imaging and clinical trials. New invasive pressure ratios that do not require hyperemia have recently emerged, and it is essential to confirm their diagnostic efficacy. The aim of this study was to validate the resting full-cycle ratio (RFR) and the diastolic pressure ratio (dPR), against [15 O]H2 O positron emission tomography (PET) imaging...

Background: The relationship between sex differences and long-term outcomes after fractional flow reserve (FFR)- and instantaneous wave-free ratio (iFR)-guided deferral of revascularization has yet to be elucidated. Methods and Results: From the J-CONFIRM registry (long-term outcomes of Japanese patients with deferral of coronary intervention based on FFR in a multicenter registry), this study included 432 lesions from 385 patients (men, 323 lesions in 286 patients; women, 109 lesions in 99 patients) with paired data of FFR and iFR...

OBJECTIVES: The objective of this study was to determine the diagnostic performance of 15 O-water positron emission tomography (PET) myocardial perfusion imaging to detect coronary artery disease (CAD) using the truth-standard of invasive coronary angiography (ICA) with fractional flow reserve (FFR) or instantaneous wave-Free Ratio (iFR) or coronary computed tomography angiogram (CCTA). BACKGROUND: 15 O-water has a very high first-pass extraction that allows accurate quantification of myocardial blood flow and detection of flow-limiting CAD...

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In patients evaluated for obstructive coronary artery disease (CAD), guidelines recommend using either fractional flow reserve (FFR) or instantaneous wave-free ratio (iFR) to guide coronary revascularization decision-making. The hemodynamic significance of lesions with discordant FFR and iFR measurements is debated. This study compared [15 O]H2 O PET-derived absolute myocardial perfusion between vessels with concordant and discordant FFR and iFR measurements. Methods: We included 197 patients suspected of obstructive CAD who had undergone [15 O]H2 O PET perfusion imaging and combined FFR/iFR interrogation in 468 vessels...

BACKGROUND: Anatomical vessel location affects post-percutaneous coronary intervention (PCI) physiology. AIMS: We aimed to compare the post-PCI instantaneous wave-free ratio (iFR) in left anterior descending (LAD) versus non-LAD vessels and to identify the factors associated with a suboptimal post-PCI iFR. METHODS: DEFINE PCI was a multicentre, prospective, observational study in which a blinded post-PCI iFR pullback was used to assess residual ischaemia following angiographically successful PCI...

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BACKGROUND: Percutaneous coronary intervention (PCI) is frequently performed to reduce the symptoms of stable angina. Whether PCI relieves angina more than a placebo procedure in patients who are not receiving antianginal medication remains unknown. METHODS: We conducted a double-blind, randomized, placebo-controlled trial of PCI in patients with stable angina. Patients stopped all antianginal medications and underwent a 2-week symptom assessment phase before randomization...

BACKGROUND: In patients undergoing percutaneous coronary intervention (PCI), it remains unclear whether intravascular imaging guidance or functional guidance is the best strategy to optimize outcomes and if the results are different in patients with vs without acute coronary syndromes (ACS). OBJECTIVES: The purpose of this study was to evaluate clinical outcomes with imaging-guided PCI or functionally guided PCI when compared with conventional angiography-guided PCI...

No abstract text is available yet for this article.