Optical Coherence Tomography-Based Functional Stenosis Assessment: FUSION-A Prospective Multicenter Trial.

BACKGROUND: Intravascular imaging and intracoronary physiology may both be used to guide and optimize percutaneous coronary intervention; however, they are rarely used together. The virtual flow reserve (VFR) is an optical coherence tomography (OCT)-based model of fractional flow reserve (FFR) facilitating the assessment of the physiological significance of coronary lesions. We aimed to validate the VFR assessment of intermediate coronary artery stenoses. METHODS: FUSION (Validation of OCT-Based Functional Diagnosis of Coronary Stenosis) was a multicenter, prospective, observational study comparing OCT-derived VFR to invasive FFR. VFR was mathematically derived from a lumped parameter flow model based on 3-dimensional lumen morphology. Patients undergoing coronary angiography with intermediate angiographic stenosis (40%-90%) requiring physiological assessment were enrolled. Investigational sites were blinded to the VFR analysis, and all OCT and FFR data were reviewed by an independent core laboratory. The coprimary end points were the sensitivity and specificity of VFR against FFR as the reference standard, each of which was tested against prespecified performance goals. RESULTS: After core laboratory review, 266 vessels in 224 patients from 25 US centers were included in the analysis. The mean angiographic diameter stenosis was 65.5%±14.9%, and the mean FFR was 0.83±0.11. Overall accuracy, sensitivity, and specificity of VFR versus FFR using a binary cutoff point of 0.80 were 82.0%, 80.4%, and 82.9%, respectively. The 97.5% lower confidence bound met the prespecified performance goal for sensitivity (71.6% versus 70%; P=0.01) and specificity (76.6% versus 75%; P=0.01). The area under the curve was 0.88 (95% CI, 0.84-0.92; P<0.0001). CONCLUSIONS: OCT-derived VFR demonstrates high sensitivity and specificity for predicting invasive FFR. Integrating high-resolution intravascular imaging with imaging-derived physiology may provide synergistic benefits as an adjunct to percutaneous coronary intervention. REGISTRATION: URL: https://clinicaltrials.gov; Unique identifier: NCT04356027.

Practical Application of Coronary Physiologic Assessment: Asia-Pacific Expert Consensus Document: Part 1.

Coronary physiologic assessment is performed to measure coronary pressure, flow, and resistance or their surrogates to enable the selection of appropriate management strategy and its optimization for patients with coronary artery disease. The value of physiologic assessment is supported by a large body of evidence that has led to major recommendations in clinical practice guidelines. This expert consensus document aims to convey practical and balanced recommendations and future perspectives for coronary physiologic assessment for physicians and patients in the Asia-Pacific region based on updated information in the field that including both wire- and image-based physiologic assessment. This is Part 1 of the whole consensus document, which describes the general concept of coronary physiology, as well as practical information on the clinical application of physiologic indices and novel image-based physiologic assessment.

Practical Application of Coronary Physiologic Assessment: Asia-Pacific Expert Consensus Document: Part 2.

Coronary physiologic assessment is performed to measure coronary pressure, flow, and resistance or their surrogates to enable the selection of appropriate management strategy and its optimization for patients with coronary artery disease. The value of physiologic assessment is supported by a large body of clinical data that has led to major recommendations in all practice guidelines. This expert consensus document aims to convey practical and balanced recommendations and future perspectives for coronary physiologic assessment for physicians and patients in the Asia-Pacific region, based on updated information in the field that includes both wire- and image-based physiologic assessment. This is Part 2 of the whole consensus document, which provides theoretical and practical information on physiologic indexes for specific clinical conditions and patient statuses.

Anonymous Comparison of Various Angiography-Derived Fractional Flow Reserve Software With Pressure-Derived Physiological Assessment.

BACKGROUND: Software to compute angiography-derived fractional flow reserve (angio-FFR) have been validated against pressure wire-derived fractional flow reserve (PW-FFR) with an area under the receiver-operating characteristic curve (AUC) of 0.93 to 0.97. OBJECTIVES: The aim of this study was to investigate diagnostic accuracies of 5 angio-FFR software/methods by an independent core lab in a prospective cohort of 390 vessels with carefully documented sites of PW-FFR and pressure wire-derived instantaneous wave-free ratio. METHODS: One "matcher investigator" colocalized on angiography the sites of pressure wire measurement with angio-FFR measurements and provided the same 2 optimal angiographic views and frame selection to independent analysts who were blinded to invasive physiological results and results from other software. The results were anonymized and randomly presented. The AUC of each angio-FFR was compared with 2-dimensional quantitative coronary angiography (QCA) percent diameter stenosis (%DS) using a 2-tailed paired comparison of AUC. RESULTS: All 5 software/methods yielded a high proportion of analyzable vessels (A: 100%, B: 100%, C: 92.1%, D: 99.5%, and E: 92.1%). The AUCs for predicting fractional flow reserve ≤0.8 for software A, B, C, D, E, and 2-dimensional QCA %DS were 0.75, 0.74, 0.74, 0.73, 0.73, and 0.65, respectively. The AUC for each angio-FFR was significantly greater than that for 2-dimensional QCA %DS. CONCLUSIONS: This head-to-head comparison by an independent core lab demonstrated that the diagnostic accuracy of various angio-FFR software for predicting PW-FFR ≤0.80 was useful, with a higher discrimination compared with 2-dimensional QCA %DS; however, it did not reach the diagnostic accuracy previously reported in validation studies of various vendors. Therefore, the intrinsic clinical value of "angiography-derived fractional flow reserve" requires confirmation in large clinical trials.

Clinical use of physiological lesion assessment using pressure guidewires: an expert consensus document of the Japanese association of cardiovascular intervention and therapeutics-update 2022.

Fractional flow reserve and instantaneous wave-free ratio are widely accepted and recommended in Western and Japanese guidelines for appropriate percutaneous coronary intervention. There are, however, many differences in clinical situations between Japan and Western countries. Therefore, the Task Force on coronary physiology of the Japanese Association of Cardiovascular Intervention and Therapeutics (CVIT) has proposed an expert consensus document to summarize current evidence and suggest the practical use of physiological lesion assessment in Japan.

Expert consensus statement for quantitative measurement and morphological assessment of optical coherence tomography: update 2022.

In this updated expert consensus document, the methods for the quantitative measurement and morphological assessment of optical coherence tomography (OCT)/optical frequency domain imaging images (OFDI) are briefly summarized. The focus is on the clinical application and the clinical evidence of OCT/OFDI to guide percutaneous coronary interventions.

A prospective multicenter validation study for a novel angiography-derived physiological assessment software: Rationale and design of the radiographic imaging validation and evaluation for Angio-iFR (ReVEAL iFR) study.

Angiography-derived physiological assessment of coronary lesions has emerged as an alternative to wire-based assessment aiming at less-invasiveness and shorter procedural time as well as cost effectiveness in physiology-guided decision making. However, current available image-derived physiology software have limitations including the requirement of multiple projections and are time consuming. METHODS/DESIGN: The ReVEAL iFR (Radiographic imaging Validation and EvALuation for Angio-iFR) trial is a multicenter, multicontinental, validation study which aims to validate the diagnostic accuracy of the Angio-iFR medical software device (Philips, San Diego, US) in patients undergoing angiography for Chronic Coronary Syndrome (CCS). The Angio-iFR will enable operators to predict both the iFR and FFR value within a few seconds from a single projection of cine angiography by using a lumped parameter fluid dynamics model. Approximately 440 patients with at least one de-novo 40% to 90% stenosis by visual angiographic assessment will be enrolled in the study. The primary endpoint is the sensitivity and specificity of the iFR and FFR for a given lesion compared to the corresponding invasive measures. The enrollment started in August 2019, and was completed in March 2021. SUMMARY: The Angio-iFR system has the potential of simplifying physiological evaluation of coronary stenosis compared with available systems, providing estimates of both FFR and iFR. The ReVEAL iFR study will investigate the predictive performance of the novel Angio-iFR software in CCS patients. Ultimately, based on its unique characteristics, the Angio-iFR system may contribute to improve adoption of functional coronary assessment and the workflow in the catheter laboratory.

Assessment of myocardial damage after acute myocardial infarction by diastolic deceleration time of coronary flow velocity using echocardiography and contrast-enhanced magnetic resonance imaging.

BACKGROUND: There are limited data available regarding the use of diastolic deceleration time (DDT) of three major arteries measured by transthoracic echocardiography (TTE) for assessing coronary microvascular damage after acute myocardial infarction (AMI). Therefore, we aimed to compare the DDT of three major arteries using TTE with the transmural extent of infarction (TEI) and infarct size, which were classified using contrast-enhanced magnetic resonance imaging (CE-MRI), in patients with AMI. METHODS: The DDT of the culprit coronary artery was measured in 74 patients using TTE and CE-MRI 1 week after the onset of AMI. The TEI was graded based on the transmural extent of the hyper-enhanced tissue (grades 1-4). RESULTS: The assessable rate for the DDT was 95%; individual rates were 100% for the left anterior descending coronary artery, 90% for the left circumflex artery, and 93% for the right coronary artery. The DDT decreased gradually as the TEI grade progressed (P = .021). Infarct size was significantly correlated with the DDT (r = -0.51, P < .0001). Univariate analysis revealed that the left ventricular (LV) end-systolic volume, LV ejection fraction, and DDT were significantly associated with TEI grade 4. After adjustment via multiple logistic regression analysis, the DDT was independently remained. With a cutoff value of 950ms, as determined by the ROC curve, DDT could detect TEI grade 4 with 81.1% sensitivity and 80.1% specificity. CONCLUSION: The DDT of three major coronary arteries measured by TTE 1 week after the onset of AMI can assess the extent of myocardial damage, which is determined by CE-MRI.

Correction to: Clinical use of physiological lesion assessment using pressure guidewires: an expert consensus document of the Japanese Association of Cardiovascular Intervention and Therapeutics.

In the original publication of the article, author group affiliation was published incorrectly. The correct affiliation for author group is given in this correction.

Different vascular healing process between bioabsorbable polymer-coated everolimus-eluting stents versus bioresorbable vascular scaffolds via optical coherence tomography and coronary angioscopy (the ENHANCE study: ENdothelial Healing Assessment with Novel Coronary tEchnology).

Recent clinical trials have raised concerns about the safety and efficacy of ABSORB™ bioresorbable vascular scaffolds (BVS). The difference in the vascular healing process between SYNERGY™ bioabsorbable polymer-coated everolimus-eluting stents (BP-EES) and BVS remains unclear. The aim of the ENHANCE study was to compare vascular healing on BP-EES versus BVS by optical coherence tomography (OCT) and coronary angioscopy (CAS) at 4- and 12-month follow-ups. This is a prospective, non-randomized, single center clinical trial. Thirteen eligible patients with multivessel disease were enrolled. BP-EES and BVS were simultaneously implanted in the same patients, but in different coronary vessels. Imaging follow-up with both OCT and CAS was completed in 11 patients at 12 months. Neointimal coverage rates were similar between the two groups based on OCT measurements. The neointimal thickness of BP-EES was significantly thicker at the 12th month than at the 4th month, whereas the neointimal thickness of BVS did not change between the measurements taken at the 4th and 12th month. Existence of intra-stent thrombus was significantly higher in the BVS group, compared to the BP-EES group. On the other hand, CAS revealed that red-thrombi and yellow-plaque were more frequently observed in BVS at 4 months and up to 12-month follow-ups than in BP-EES. These findings suggested that the evidence of instability remained up to 12 months in the vascular healing with BVS, compared to that with BP-EES. Vascular healing of the stented wall was recognized at the very early phase after BP-EES implantation. However, vascular healing with BVS was still incomplete after 12 months.

Expert consensus statement for quantitative measurement and morphological assessment of optical coherence tomography.

In this document, the methods for the quantitative measurement and morphological assessment of optical coherence tomography (OCT)/optical frequency domain imaging images (OFDI) are briefly summarized. The focus is on the clinical application of OCT/OFDI to guide percutaneous coronary interventions.

QFR Versus FFR Derived From Computed Tomography for Functional Assessment of Coronary Artery Stenosis.

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 (FFRCT) using fractional flow reserve (FFR) as the reference standard. BACKGROUND: QFR and FFRCT are recently developed, less invasive techniques for functional assessment of coronary artery disease. METHODS: QFR, FFRCT, and FFR were measured in 152 patients (233 vessels) with stable coronary artery disease. RESULTS: QFR was highly correlated with FFR (r = 0.78; p < 0.001), whereas FFRCT was moderately correlated with FFR (r = 0.63; p < 0.001). Both QFR and FFRCT showed moderately good agreement with FFR, presenting small values of mean difference but large values of root mean squared deviation (FFR-QFR, 0.02 ± 0.09; FFR-FFRCT, 0.03 ± 0.11). The sensitivity, specificity, positive predictive value, and negative predictive value of QFR ≤0.80 for predicting FFR ≤0.80 were 90%, 82%, 81%, and 90%, respectively. Those of FFRCT ≤0.80 for predicting FFR ≤0.80 were 82%, 70%, 70%, and 82%, respectively. The diagnostic accuracy of QFR ≤0.80 for predicting FFR ≤0.80 was 85% (95% confidence interval [CI]: 81% to 89%), whereas that of FFRCT ≤0.80 for predicting FFR ≤0.80 was 76% (95% CI: 70% to 80%). CONCLUSIONS: QFR and FFRCT showed significant correlation with FFR. Mismatches between QFR and FFR and between FFRCT and FFR were frequent.

Imaging assessment and accuracy in coronary artery autopsy: comparison of frequency-domain optical coherence tomography with intravascular ultrasound and histology.

Optical coherence tomography (OCT) is a coronary artery imaging technique with high resolution. Second-generation frequency-domain OCT (FD-OCT) technology allows safer and faster clinical application compared with first-generation time-domain OCT (TD-OCT). Only limited validation studies compare FD-OCT with other modes of analysis: histology, which is the current gold standard, and intravascular ultrasound (IVUS). This study therefore aims to demonstrate the accuracy of FD-OCT images compared with IVUS and histology. FD-OCT and IVUS images were acquired from 203 segments from 31 coronary arteries obtained at autopsy from 20 cadavers. Of these, 30 randomly-selected pairs were used to create three classifications of plaque type based on morphological features in FD-OCT and IVUS compared with corresponding histopathology. The remaining 173 pairs were used to demonstrate the diagnostic accuracy for classification of coronary plaques by FD-OCT. Plaque type distributions were 27% fibroatheroma, 22% fibrocalcific plaque and 51% fibrous plaque. The diagnostic accuracies of FD-OCT for fibroatheroma, fibrocalcific plaque and fibrous plaque were 90, 95 and 93%, respectively. Those of IVUS were 81, 89 and 84%, respectively. FD-OCT achieved high diagnostic accuracy for the classification of coronary plaques comparable to TD-OCT. Physicians should consider the differences in the ability to classify plaque morphology of OCT of imaging devices when applying their use.

Influence of Sex on Relationship Between Total Anatomical and Physiologic Disease Burdens and Their Prognostic Implications in Patients With Coronary Artery Disease.

Background Total atherosclerosis disease burden is associated with clinical outcomes in patients with coronary artery disease. However, the influence of sex on the relationship between total anatomical and physiologic disease burdens and their prognostic implications have not been well defined. Methods and Results A total of 1136 patients who underwent fractional flow reserve (FFR) measurement in all 3 major coronary arteries were included in this study. Anatomical and physiologic total disease burden was assessed by SYNTAX (Synergy Between Percutaneous Coronary Intervention With Taxus and Cardiac Surgery) score, residual SYNTAX score, a total sum of FFR in 3 vessels (3-vessel FFR), and functional SYNTAX score. The primary end point was major adverse cardiac events, a composite of cardiac death, myocardial infarction, and ischemia-driven revascularization at 2 years. There were no differences in angiographic diameter stenosis, SYNTAX score, or residual SYNTAX score between women and men. However, both per-vessel FFR (0.89±0.10 versus 0.87±0.11, P<0.001) and 3-vessel FFR (2.72±0.13 versus 2.69±0.15, P<0.001) were higher in women. Multivariable Cox regression analyses showed that total anatomical and physiologic disease burdens were significantly associated with 2-year major adverse cardiac events, and there was no significant interaction between sex and total disease burden for clinical outcomes. Conclusions Despite similar angiographic disease severity, both per-vessel and per-patient physiologic disease severity was less in women than in men. There was no influence of sex on prognostic implications of total anatomical and physiologic disease burdens in patients with coronary artery disease. Clinical Trial Registration URL: https://www.clinicaltrials.gov . Unique identifier: NCT01621438.

Assessment of decreased left ventricular longitudinal deformation in asymptomatic patients with organic mitral regurgitation and preserved ejection fraction using tissue-tracking mitral annular displacement by speckle-tracking echocardiography.

BACKGROUND: Application of speckle-tracking echocardiography (STE) provides rapid assessment of tissue-tracking mitral annular displacement (TMAD). We investigated the value of TMAD for the assessment of decreased LV longitudinal deformation in asymptomatic patients with severe or moderate-to-severe mitral regurgitation (MR) and preserved LV ejection fraction (LVEF). METHODS: We retrospectively studied 50 patients with severe or moderate-to-severe organic MR and preserved LVEF (>60%) in whom global longitudinal strain (GLS) was successfully measured by STE. TMAD was quickly assessed in the apical four-chamber view using STE. We calculated the percentage of TMAD to LV length from the midpoint of mitral annulus to the apex at end-diastolic (%TMAD). The study population was divided into two groups: decreased GLS patients (>-20%; Group A) and preserved GLS patients (≤-20%; Group B). We examined whether %TMAD could be used as a diagnostic factor of decreased GLS. RESULTS: %TMAD was significantly lower in Group A than Group B (12.5 ± 0.5 vs 16.8 ± 2.2, P < 0.0001). By univariate logistic regression analysis, %TMAD was a diagnostic factor of decreased GLS. By multiple regression analysis, %TMAD remained an independent diagnostic factor of decreased GLS (Odds ratio [OR] = 4.21, 95% confidence interval [CI] = 1.34-28.94, P < 0.0001). A cutoff value of %TMAD <14.6 had a sensitivity of 94% and specificity of 94% for the presence of decreased GLS. CONCLUSIONS: Tissue-tracking mitral annular displacement is useful in the assessment of decreased LV longitudinal deformation in asymptomatic patients with severe or moderate-to-severe MR and preserved LVEF.

Treatment strategy modification and its implication on the medical cost of fractional flow reserve-guided percutaneous coronary intervention in Japan.

BACKGROUND: Fractional flow reserve (FFR)-guided percutaneous coronary intervention (PCI) could improve outcome compared with angiography-guided PCI. However, the economic impact of FFR-guided PCI remains largely unknown in the medical system in Japan. We evaluated the impact of treatment strategy modification by FFR measurement on the direct medical cost using a model analysis with a decision tree model in Japan. METHODS: For the clinical parameters set in the model, the findings from CVIT-DEFER registry were adopted. Cost parameters were considered on the assumption that coronary angiography, FFR measurement, and the treatment are performed at Diagnosis Procedure combination (DPC) hospitals, and the costs were calculated based on the medical fee reimbursement systems in Japan. RESULTS: The probability of deferral of PCI in patients who were allocated to PCI based on coronary angiography was set as 90.1% based on the CVIT-DEFER registry. In the model analysis, the cost of tests was increased by 185,660 JPY per patient by the addition of FFR measurement, but the cost of treatment with PCI was reduced by 561,425 JPY per patient, and the entire cost of treatment was reduced by 322,675 JPY, resulting in the expected reduction in the total expected medical cost by 137,015 JPY per patient. CONCLUSION: Under contemporary Japanese practice, FFR-guided PCI has potential to reduce the medical cost by effective reassessment of coronary stenosis and reducing inappropriate application of PCI.

Value of tissue-tracking tricuspid annular plane by speckle-tracking echocardiography for the assessment of right ventricular systolic dysfunction.

BACKGROUND: Assessment of right ventricular (RV) function remains challenging because of its complex geometry. Application of speckle-tracking echocardiography (STE) to the tricuspid annulus provides rapid and automated assessment of the midpoint of the tricuspid annular plane displacement (TAD). The aim of this study was to investigate the value of tissue-tracking TAD for the assessment of RV systolic dysfunction. METHODS: We retrospectively studied 61 patients in whom RV ejection fraction (EF) measured by 3-dimensional echocardiography was performed. STE-derived displacement of the midpoint between the septal and lateral tricuspid annulus and its percentage of RV length at end-diastole (MTAD) were automatically assessed. We performed comparative analyses between the RVEF ≥45% group and the RVEF <45% group in each parameter for the assessment of RV systolic function. RESULTS: MTAD was successfully assessed in 56 (91.2%). According to receiver operating characteristics analysis, RVEF <45% was best detected by MTAD <14.7% with area under curve (AUC) 0.97, sensitivity 93%, specificity 95%, followed by RV free wall longitudinal strain (AUC 0.86), RV fractional area change (AUC 0.84), tricuspid annular plane systolic excursion (AUC 0.79), and systolic peak velocity of tricuspid annulus (AUC 0.70), although there was no significant difference between MTAD and RV free wall strain (P = 0.14). CONCLUSION: The present study showed that MTAD was simple index and useful for the assessment of RV systolic dysfunction.

Clinical use of physiological lesion assessment using pressure guidewires: an expert consensus document of the Japanese Association of Cardiovascular Intervention and Therapeutics.

In this document, the background, concept, and current evidence are briefly summarized. The focus is on the clinical application of physiological lesion assessment from a practical standpoint for facilities that do not have ample experience. Finally, the characteristics of new resting indexes are summarized.

Quantitative flow ratio and instantaneous wave-free ratio for the assessment of the functional severity of intermediate coronary artery stenosis.

OBJECTIVE: Quantitative flow ratio (QFR) is a novel physiological index of the severity of coronary stenosis. The aim of the present study was to investigate the relationship between QFR and the instantaneous wave-free ratio (iFR). PATIENTS AND METHODS: We analyzed contrast-flow QFR, iFR, and fractional flow reserve (FFR) in 100 coronary arteries with intermediate stenosis. RESULTS: There was a high correlation (r=0.71, P<0.001) and a good agreement (mean difference: -0.09±0.11) between QFR and iFR. Both QFR and iFR were correlated significantly with FFR (r=0.89, P<0.001 and r=0.76, P<0.001, respectively). The mean absolute difference between FFR and QFR was significantly smaller than that between FFR and iFR (-0.01±0.07 vs. -0.08±0.09, P<0.001). The diagnostic accuracy of QFR less than or equal to 0.80 for predicting FFR less than or equal to 0.80 was numerically higher than that of iFR less than or equal to 0.89 for predicting FFR less than or equal to 0.80 [QFR: 94% (95% confidence interval: 85-97%) vs. iFR: 74% (95% confidence interval: 65-81%)]. CONCLUSION: QFR was correlated highly with iFR as well as FFR. Like FFR and iFR, QFR might be reliable for assessing the physiological severity of coronary stenosis in the angiographic intermediate lesions.