Intermediate Coronary Stenosis Research Articles

Safety and efficacy of antiplatelet therapy in patients with intermediate coronary artery stenosis and deferred revascularization.

This study investigated the safety and efficacy of antiplatelet therapy in patients with intermediate coronary artery stenosis who underwent deferred revascularization due to their fractional flow reserve (FFR). A nationwide cohort study was conducted using the Korean National Health Insurance Service database. A total of 4657 patients with intermediate coronary artery stenosis who underwent deferred revascularization due to their FFR were identified from 2013 to 2020. FFR was indicated in patients with no prior evidence of myocardial ischemia and intermediate coronary artery stenosis (50%-70%) as determined by quantitative coronary angiography. Patients were classified according to whether antiplatelet therapy was initiated after the index procedure. The primary efficacy outcome was major adverse cardiac and cerebrovascular events (MACCE), a composite of all-cause death, myocardial infarction, unplanned revascularization, and stroke, during a 5-year follow-up period. The primary safety outcome was any gastrointestinal bleeding. After propensity score matching, there were 1634 patients in the antiplatelet therapy group and 1634 in the nonantiplatelet therapy group. The risk of MACCE was similar between the 2 groups (24.8% vs 24.7%; adjusted HR, 0.97; 95%CI, 0.84-1.13; P = 0.745). The risk of gastrointestinal bleeding was higher in the antiplatelet therapy group than in the nonantiplatelet therapy group (2.2% vs 1.2%; aHR, 2.07; 95%CI, 1.08-4.00). These results were similar in subgroup analyses. In patients with intermediate coronary artery stenosis who underwent deferred revascularization due to their FFR, antiplatelet therapy may increase the risk of gastrointestinal bleeding without reducing the risk of future ischemic events.

Quantitative flow ratio versus fractional flow reserve for coronary revascularisation guidance (FAVOR III Europe): a multicentre, randomised, non-inferiority trial

Fractional flow reserve (FFR) or non-hyperaemic pressure ratios are recommended to assess functional relevance of intermediate coronary stenosis. Both diagnostic methods require the placement of a pressure wire in the coronary artery during invasive coronary angiography. Quantitative flow ratio (QFR) is an angiography-based computational method for the estimation of FFR that does not require the use of pressure wires. We aimed to investigate whether a QFR-based diagnostic strategy yields a non-inferior 12-month clinical outcome compared with an FFR-based strategy. FAVOR III Europe was a multicentre, randomised, open-label, non-inferiority trial comparing a QFR-based with an FFR-based diagnostic strategy for patients with intermediate coronary stenosis. Enrolment was performed in 34 centres across 11 European countries. Patients aged 18 years or older with either chronic coronary syndrome or stabilised acute coronary syndrome, and with at least one intermediate non-culprit stenosis (40-90% diameter stenosis by visual estimate; referred to here as a study lesion), were randomly assigned (1:1) to the QFR-guided or the FFR-guided group. Randomisation was done using a concealed web-based system and was stratified by diabetes and presence of a left anterior descending coronary artery study lesion. The primary endpoint was a composite of death, myocardial infarction, and unplanned revascularisation at 12 months. The predefined non-inferiority margin was 3·4% and the primary analysis was performed in the intention-to-treat population. The trial was registered with ClinicalTrials.gov (NCT03729739) and long-term follow-up is ongoing. Between Nov 6, 2018, and July 21, 2023, 2000 patients were enrolled and randomly assigned to the QFR-guided strategy (1008 patients) or the FFR-guided strategy (992 patients). The median age was 67·3 years (IQR 59·9-74·7); 1538 (76·9%) patients were male and 462 (23·1%) were female. Median follow-up time was 365 days (IQR 365-365). At 12 months, a primary endpoint event had occurred in 67 (6·7%) patients in the QFR group, and in 41 (4·2%) patients in the FFR group (hazard ratio 1·63 [95% CI 1·11-2·41]). The event proportion difference was 2·5% (90% two-sided CI 0·9-4·2). The upper limit of the 90% CI exceeded the prespecified non-inferiority margin of 3·4%. Therefore, QFR did not meet non-inferiority to FFR. A total of 18 (1·8%) patients in each group experienced an adverse procedural event, the most frequent being procedure-related myocardial infarction, which occurred in ten (1·0%) patients in the QFR group and seven (0·7%) in the FFR group. One patient in the QFR group died in relation to the index procedure. The results of the FAVOR III Europe trial do not support the use of QFR if FFR is available to guide revascularisation decisions in patients with intermediate coronary stenosis. This finding could have implications for current clinical guidelines recommending QFR for this purpose. Medis Medical Imaging Systems and Aarhus University.

Predictive value of plaque characteristics assessed by coronary computed tomography angiography and optical coherence tomography for identification of lesions causing ischemia

Abstract Background In patients with intermediate coronary stenosis, the functional assessment with fractional flow reserve (FFR) and the anatomical assessment with optical coherence tomography (OCT) have been widely used in clinical practice. Additionally, coronary computed tomography angiography (CTA) is commonly used non-invasive imaging technique for evaluating suspected coronary artery disease before being referred for angiography. Objectives This study sought to investigate the association between FFR and plaque characteristics assessed by coronary CTA and OCT in intermediate coronary stenosis. Methods Based on the prospective multicentre registry, a total of 159 patients including 339 coronary lesions with intermediate stenosis were included. All patients underwent coronary CTA before being referred for coronary angiography and both FFR measurement and OCT examination were performed during angiography. The stenotic lesion with FFR ≤0.80 was considered diagnostic of lesion causing ischemia. The predictive value of plaque characteristics assessed by coronary CTA and OCT for identifying lesions causing ischemia was analyzed. Results Stenosis severity and plaque characteristics on coronary CTA and OCT were different between the lesions causing ischemia versus not causing ischemia. On multivariate analysis, low attenuation plaque on coronary CTA (odds ratio [OR]= 2.78; P=0.038) and thrombus (OR=5.13; 0.042), plaque rupture (OR=3.25; P=0.017), and intimal vasculature on OCT (OR=2.57; P=0.012) were independent predictors for the lesions causing ischemia. Increasing number of these plaque characteristics offered incremental improvement in predicting the lesions causing ischemia. Conclusions Comprehensive anatomical evaluation of coronary stenosis may be able to provide additional supportive information for predicting the lesions causing ischemia.

Diastolic hyperemia-free ratio for the assessment of intermediate coronary artery stenosis in patients with hemodialysis

Abstract Background Diastolic hyperemia-free Ratio (DFR) is new resting index and uses a pragmatic definition by including areas below the average aortic pressure with negative slope. Hemodialysis (HD) exhibits left ventricular hypertrophy and impaired microcirculation. The relationship between DFR and fractional flow reserve (FFR) in the patients with HD has not been yet investigated. Purpose We aimed to compare the rate of physiological discordance between HD patients and non-HD patients, and to elucidate the best DFR cut-off value predicting less than 0.80 of FFR in HD patients. Methods We enrolled 761 consecutive patients (1033 vessels) who underwent both DFR and FFR in the intermediate coronary artery stenosis between July 2020 and December 2023 in our hospital. The cutoff values of DFR 0.89 or less and FFR 0.80 or less were used for the study. We compared the DFR values with FFR values between HD group and Non-HD group. Results HD group consisted of 110 patients and Non-HD group consisted of 651 patients. A good correlation between DFR and FFR was observed in HD group (R=0.780 ; p < 0.0001) and Non-HD group (R=0.770 ; p < 0.0001). The rate of physiological discordance between HD group and non-HD group was each 31.3% and 20.5% (p < 0.01). Receiver operating characteristic curve showed that a suitable cut off value of DFR for equivalent FFR value of 0.80 was 0.84 in HD group and 0.89 in Non-HD group, respectively (Figure). Conclusion In the patients with HD, DFR may overestimate intermediate coronary artery stenosis and the suitable cut off value was 0.84.2024 ESC HD DFR Figure

Antiplatelet agents in patients with intermediate coronary artery stenosis and deferred revascularization

Abstract Background There is no specific recommendation regarding optimal antiplatelet therapy after deferral of revascularization in patients with established coronary artery disease. Objectives The current study investigated safety and efficacy of antiplatelet therapy in patients with intermediate coronary artery stenosis in whom revascularization was deferred based on fractional flow reserve (FFR). Methods In the Korean National Health Insurance Service database 2013-2020, we identified 4,657 patients who had intermediate coronary artery disease on angiography for which revascularization was deferred based on FFR. During this period, reimbursement criteria of FFR were patients with no previous evidence of myocardial ischemia and intermediate coronary artery stenosis (50-70%) by quantitative coronary angiography. Patients were then classified into two groups according to initiation of antiplatelet therapy after the index procedure. Primary efficacy outcome was major adverse cardiac and cerebrovascular events (MACCE), a composite of all-cause death, myocardial infarction, unplanned revascularization, and stroke, during 5 years of follow-up. Primary safety outcome was any gastrointestinal bleeding. Results After propensity score matching in a 1:1 ratio, there were 1,634 patients in antiplatelet therapy group and 1,634 in no therapy group (total N=3,268). The risk of MACCE was similar between the two groups (24.8% vs. 24.7%; adjusted hazard ratio [aHR], 0.97; 95% confidence interval [CI], 0.84-1.13; P=0.745). However, the risk of any gastrointestinal bleeding was higher in antiplatelet therapy group than no therapy group (2.2% vs. 1.2%; aHR, 2.07, 95% CI, 1.08-4.00). These results were consistently found in subgroup analyses. Conclusions In patients with intermediate coronary artery stenosis with deferred revascularization based on FFR, antiplatelet therapy was not associated with reduced risk of ischemic events but increased risk of gastrointestinal bleeding.

Relationship between diastolic hyperemia-free ratio and fractional flow reserve in patients with aortic valve stenosis

Abstract Background Diastolic hyperemia-free Ratio (DFR) is new resting index and uses a pragmatic definition by including areas below the average aortic pressure with negative slope. Aortic valve stenosis (AS) exhibits left ventricular hypertrophy and impaired microcirculation. The relationship between DFR and fractional flow reserve (FFR) in the patients with AS has not been yet investigated. Purpose We aimed to compare DFR and FFR in each of AS group and Non-AS group and to elucidate a suitable DFR cut-off value predicting less than 0.80 of FFR. Methods We enrolled 761 consecutive patients (1033 vessels) who underwent both DFR and FFR in the intermediate coronary artery stenosis between July 2020 and December 2023 in our hospital. We compared the DFR values with FFR values between AS group and Non-AS group. AS was defined as an aortic valve area of 1.5 cm2 or less, a mean aortic valve gradient of 20 mm Hg or more, or a peak aortic-jet velocity of 3.0 m/s or more. Results AS group consisted of 55 patients and Non-AS group consisted of 706 patients. A good correlation between DFR and FFR was observed in AS group (R=0.713; p < 0.0001) and Non-AS group (R=0.758; p < 0.0001). The patient backgrounds were similar between AS and Non-AS groups (Table). Regarding physiological findings, DFR in AS group was significantly lower than in Non-AS group (0.83 ± 0.12 vs. 0.88 ± 0.11, p < 0.0001), but FFR was similar (0.80 ± 0.07 vs. 0.81 ± 0.10, p = 0.12). Receiver operating characteristic curve showed that a suitable cut off value of DFR for equivalent FFR value of 0.80 was 0.85 in AS group and 0.89 in Non-AS group, respectively (Figure). Conclusion In the patients with AS, DFR may overestimate intermediate coronary artery stenosis and the suitable cut off value was 0.85.2024 ESC AS DFR Table2024 ESC AS DFR Figure

Prognostic implications of microvascular resistance reserve in symptomatic patients with intermediate coronary stenosis

Abstract Background Microvascular resistance reserve (MRR) is a novel index reflecting coronary microcirculatory function, irrespective of epicardial coronary artery stenosis. There is limited evidence regarding whether MRR can be an independent prognostic tool in patients with stable ischemic heart disease (IHD). Objective To evaluate clinical outcomes according to MRR in patients with stable IHD accompanied with or without significant epicardial coronary artery stenosis. Methods The current study included 547 consecutive patients undergoing systematic echocardiographic and invasive physiologic assessment for suspected stable IHD. Significant epicardial coronary artery stenosis was defined as fractional flow reserve (FFR)≤0.80. Coronary microvascular dysfunction (CMD) was defined as MRR≤3.0. Primary outcome was major adverse cardiovascular event (MACE), a composite of cardiovascular death, myocardial infarction, repeat revascularization, and admission for heart failure. Results Among the total patients, 172 patients (31.4%) had FFR≤0.80 and 200 patients (36.6%) had CMD defined by MRR≤3.0. MRR showed no significant correlation with FFR (R=-0.031, P=0.469), however, it was significantly correlated with index of microcirculatory resistance (R=-0.353, P<0.001), NT-proBNP (R=-0.296, P<0.001), left ventricular filling pressure (E/e’) (R=-0.224, P<0.001), and diastolic dysfunction grade (P<0.001). During median follow-up of 3.3 years (interquartile range from 2.0 to 4.5 years), MRR was significantly associated with MACE risk (HR 1.23 per-1 decrease, 95% CI 1.12-1.36, P<0.001). CMD defined by MRR≤3.0 was associated with an increased MACE risk in both FFR>0.80 (41.0% vs. 26.0%; HRadj 1.59, 95% CI 1.07-2.35, P=0.021) and FFR≤0.80 (34.7% vs. 14.8%; HRadj 2.32, 95% CI 1.12-4.82, P=0.024) groups. Conclusion Decreased MRR was associated with the presence of cardiac diastolic dysfunction as well as with increased left ventricular filling pressure. The presence of CMD defined by MRR was independently associated with the risk of a composite of cardiovascular death, myocardial infarction, repeat revascularization, and admission for heart failure in patients with stable IHD, irrespective of significant epicardial coronary artery stenosis.

VERMONT non-optimised: can baseline diagnostic catheter images be used to measure angiography based CAAS-vFFR?

Abstract Background We have previously reported strong diagnostic accuracy and validity of angiography-based vessel Fractional Flow Reserve (CAAS-vFFR) compared to conventional wire based Fractional Flow Reserve (FFR)(1). The CAAS-vFFR system requires at least two additional optimised angiographic cine images taken after intracoronary glyceryl trinitrate administration, separated by ≥ 30 degrees at a frame-rate of ≥ 15 frames/seconds with minimal overlap and foreshortening, no table movement and adequate contrast opacification. At present, there is a paucity of data regarding the validity of using baseline non-optimised diagnostic cine images in the assessment of CAAS-vFFR. Purpose To assess the concordance and validity of using baseline non-optimised diagnostic cine images in measuring angiography based CAAS-vFFR. Methods We conducted an investigator-initiated, single centre, blinded, prospective observational study performing wire based FFR and CAAS-vFFR conducted simultaneously in patients undergoing routine wire-based FFR for intermediate coronary stenoses. All eligible patients had baseline diagnostic and optimised guide-catheter based angiographic images acquired. Results 195 consecutive patients with 205 lesions were recruited over 19 months; 56 (27.3%) lesions were excluded due to inadequate baseline cine angiogram images (Picture 1). 102 (68.5%) had stable symptoms and 107 (71.8%) were male. The median age was 65.0 years (interquartile range 59.0 – 73.0) and mean body-mass-index was 29.2 kg/m2 (± 5.8). There were 117 (78.5%) lesions in the left anterior descending artery/diagonal branches, 20 (13.4%) in the right coronary artery and 12 (8.1%) in the left circumflex artery/marginal branches. There were 93 (62.4%) diffuse (≥ 20 cm), 23 (15.4%) bifurcation and 15 (10.1%) ostial lesions. The mean optimised vFFR and non-optimised vFFR were 0.80 (± 0.1) and 0.79 (± 0.1) respectively with a Pearson correlation of 0.87 (p<0.001). Overall, 52 lesions (34.9%) and 73 lesions (49.0%) had a wire-based FFR and non-optimised vFFR value of ≤ 80 respectively. The mean wire-based FFR and non-optimised vFFR were 0.82 (± 0.1) and 0.79 (± 0.1) respectively. Receiver operating characteristic (ROC) curve analysis revealed excellent diagnostic accuracy of non-optimised vFFR in predicting a wire based FFR of ≤ 80 (AUC 0.91; 95% CI; 0.87-0.96) (Picture 2). Baseline non-optimised diagnostic vFFR images produced a sensitivity of 94.2%, specificity of 75.3%, positive-predictive-value (PPV) of 67.1% and negative-predictive-value (NPV) of 96.1% compared with wire-based FFR. Conclusions CAAS-vFFR derived values from baseline non-optimised diagnostic cine images were strongly concordant with those derived from optimised images and displayed a high sensitivity and NPV compared to wire-based FFR. This reflects the potential for CAAS-vFFR to have broader clinical applications and be utilised as a retrospective screening tool for intermediate lesions.Excluded baseline angiogram lesionsROC Curve

Comparison of vessel-Fractional Flow Reserve (vFFR) and Quantitative Flow Ratio (QFR) using instantaneous wave-Free Ratio (iFR) or Resting Full-cycle Ratio (RFR) as reference

Abstract Background Angiography-based functional assessment remains the state of the art to assess the hemodynamic relevance of intermediate coronary stenoses. In addition to fractional flow reserve (FFR), adenosin free indices like instantaneous wave-free ratio (iFR) or resting full-cycle ratio (RFR) are widely used for the invasive evaluation. Although these methods are widely accepted, they are underused in clinical routine due to costs, their invasive nature, longer procedural times, and lack of availability. Vessel-fractional flow reserve (vFFR) and quantitative flow ratio (QFR) are new software-based methods for the evaluation of coronary-physiology. The aim of this study is to compare vFFR and QFR with the established invasive methods iFR or RFR. Methods We prospectively analyzed 95 Patients in our QFR-Registry vFFR- and QFR-computation was performed three-times by two certified, blinded, and independent experts using the QAngio XA 3D 3.2- and CAAS-software, respectively. Results: 101 main epicardial coronary arteries (52 LAD; 19 LCx; 30 RCA) were analyzed using vFFR, QFR and iFR or RFR. vFFR showed a good correlation with adenosine-free indices in all 3 measurements (AUC 0.883 with r=0.672, p<0.001; AUC 0.841 with r=0.618 p<0.001; AUC 0.840 with r=0.592, p<0.001 respectively). The diagnostic accuracy between the three vFFR-measurements and iFR/RFR was 83%; 81% and 79% respectively. QFR-computations showed a similar correlation with iFR/RFR (AUC 0.899 with r=0.720, p<0.001; AUC 0.919 with r=0.649, p<0.001; AUC 0.930 with r=0.703, p<0.001 respectively) with a diagnostic accuracy 88%, 89% and 88% respectively. The intra- and inter-observer reliability for vFFR (intra: mean difference 0.002±0.0568; inter: 0.024±0.054) and QFR (intra: mean difference 0.018±0.071; inter: 0.016±0.075) analyzed in a Bland-Altman Blot showed a good correlation between virtual assessments and invasive measurements with iFR/RFR. Conclusion The data show a good diagnostic agreement between vFFR and QFR and adenosine free invasive assessments. vFFR and QFR appear reasonable alternative approaches for the evaluation of intermediate stenoses. These data provide the rational to prospectively test for a clinical noninferiority of the non-invasive flow measurements.Diagnostic performance of vFFR/cQFR

Non-invasive physiological assessment of intermediate coronary stenoses from plain angiography through artificial intelligence: the STARFLOW system.

Despite evidence supporting use of fractional flow reserve (FFR) and instantaneous waves-free ratio (iFR) to improve outcome of patients undergoing coronary angiography (CA) and percutaneous coronary intervention, such techniques are still underused in clinical practice due to economic and logistic issues. We aimed to develop an artificial intelligence (AI)-based application to compute FFR and iFR from plain CA. Consecutive patients performing FFR or iFR or both were enrolled. A specific multi-task deep network exploiting 2 projections of the coronary of interest from standard CA was appraised. Accuracy of prediction of FFR/iFR of the AI model was the primary endpoint, along with sensitivity and specificity. Prediction was tested both for continuous values and for dichotomous classification (positive/negative) for FFR or iFR. Subgroup analyses were performed for FFR and iFR.A total of 389 patients from 5 centers were enrolled. Mean age was 67.9±9.6 and 39.2% of patients were admitted for acute coronary syndrome. Overall, the accuracy was 87.3% (81.2-93.4%), with a sensitivity of 82.4% (71.9-96.4%) and a specificity of 92.2% (90.4-93.9%). For FFR, accuracy was 84.8% (77.8-91.8%), with a sensitivity of 81.9% (69.4-94.4%) and a specificity of 87.7% (85.5-89.9%), while for iFR accuracy was 90.2% (86.0-94.6%), with a sensitivity of 87.2% (76.6-97.8%) and a specificity of 93.2% (91.7-94.7%, all confidence intervals 95%). The presented machine-learning based tool showed high accuracy in prediction of wire-based FFR and iFR.

TCT-220 Virtual Stenting With Quantitative Flow Ratio as Tool to Predict the Hemodynamic Effect of Treating Intermediate Coronary Artery Stenosis

TCT-220 Virtual Stenting With Quantitative Flow Ratio as Tool to Predict the Hemodynamic Effect of Treating Intermediate Coronary Artery Stenosis

Selective FFRCT testing in suspected stable angina in clinical practice - initial experiences

Coronary CT angiography (CTA) derived fractional flow reserve (FFRCT) is recommended for physiological assessment in intermediate coronary stenosis for guiding referral to invasive coronary angiography (ICA). In this study, we report real-world data on the feasibility of implementing a CTA/FFRCT test algorithm as a gatekeeper to ICA at referral hospitals. Retrospective all-comer study of patients with new onset stable symptoms and suspected coronary stenosis (30–89%) by CTA. Evaluation of CTA datasets, interpretation of FFRCT analysis, and decisions on downstream testing were performed by skilled CT-cardiologists. CTA was performed in 3974 patients, of whom 381 (10%) were referred directly to ICA, whereas 463 (12%) to non-invasive functional testing: FFRCT 375 (81%) and perfusion imaging 88 (19%). FFRCT analysis was rejected in 8 (2%) due to inadequate CTA image quality. Number of patients deferred from ICA after FFRCT was 267 (71%), while 100 (27%) were referred to ICA. Obstructive coronary artery disease (CAD) was confirmed in 62 (62%) patients and revascularization performed in 53 (53%). Revascularization rates, n (%), were higher in patients undergoing FFRCT-guided versus CTA-guided referral to ICA: 30–69% stenosis, 28 (44%) versus 8 (21%); 70–89% stenosis, 39 (69%) versus 25 (46%), respectively, both p < 0.05. Implementation of FFRCT at referral hospitals was feasible, reduced the number of invasive procedures, and increased the revascularization rate.

Validation of angiography-derived Murray law-based quantitative flow reserve (μQFR) against pressure-derived instantaneous wave-free ratio for assessing coronary lesions, a single-center study in Egypt

BackgroundInstantaneous wave-free ratio (iwFR) is a well-validated method for functional evaluation of intermediate coronary lesions. A recently developed Murray law-based QFR (µQFR) allows wire-free FFR estimation using a high-quality single angiographic projection. We aim to determine the diagnostic accuracy of µQFR as compared to wire-based iwFR for physiological assessment of coronary lesions in a sample of Egyptian patients.ResultsOver a one-year period, patients who previously underwent iwFR assessment of an intermediate coronary stenosis (40–90%) were retrospectively included. μQFR analysis was then performed offline using a dedicated artificial intelligence (AI)-aided computation software. All the measurements were performed blinded to iwFR results, and the agreement between iwFR and μQFR values was tested. Forty-nine patients (mean age 57.9 ± 9 years, 72.9% males) were included. Mean value of iwFR and μQFR was 0.90 ± 0.075 and 0.79 ± 0.129, respectively. There was a significant moderate positive linear correlation between μQFR and iwFR (r = 0.47, p = 0.001; 95% CI 0.22–0.68) with moderate-to-substantial agreement between the two methods (Kappa 0.6). In assessing the diagnostic accuracy of μQFR, the receiver operating characteristic (ROC) curve yielded an area under the curve (AUC) of 0.84 (95% CI 0.717–0.962) for predicting functionally significant lesions defined as iwFR < 0.89. The sensitivity and specificity of μQFR < 0.8 for detecting physiological significance of coronary lesions were 89% and 74% with positive and negative predictive values of 70 and 91%, respectively.ConclusionµQFR has good diagnostic accuracy for predicting functionally significant coronary lesions with moderate correlation and agreement with the gold standard iwFR. Angiography-derived µQFR could be a promising tool for improving the utilization of physiology-guided revascularization.

Fractional flow reserve or optical coherence tomography for angiographically intermediate coronary stenoses: 5-year outcomes in the FORZA trial.

Fractional flow reserve or optical coherence tomography for angiographically intermediate coronary stenoses: 5-year outcomes in the FORZA trial.

Combined assessment of fractional flow reserve, resting full-cycle ratio, and resting ratio of distal coronary to aortic pressure for clinical outcomes

BackgroundFractional flow reserve (FFR) and non-hyperemic indices are invasive standards for evaluating functional significance of coronary stenosis. However, data are limited about outcomes in vessels with concordant and discordant physiological results, particularly with a ratio of distal coronary to aortic pressure (Pd/Pa) at rest. MethodsThis was a single-center, retrospective, observational study. Coronary physiological indices including FFR, resting full-cycle ratio (RFR), and resting Pd/Pa were invasively evaluated in vessels with intermediate coronary artery stenosis. FFR ≤0.80, RFR ≤0.89, and resting Pd/Pa ≤0.92 were considered physiologically positive. Vessels were divided into three groups according to the results of FFR, RFR, and resting Pd/Pa: concordant positive (all positive for FFR, RFR, and resting Pd/Pa), concordant negative (all negative for FFR, RFR, and resting Pd/Pa), and discordant groups. The primary endpoint was target vessel failure (TVF) defined as a composite of cardiac death and target vessel myocardial infarction and unplanned revascularization. ResultsOf 987 vessels included, 311 (31.5 %), 263 (26.6 %), and 413 (41.9 %) were in the concordant positive, discordant, and concordant negative groups. During a median follow-up period of 417 (208–756) days, TVF occurred more frequently in the concordant positive group, followed by the discordant and concordant negative groups (7.7 % vs. 4.6 % vs. 2.4 %, p = 0.004). TVF increasingly accrued during long-term follow-up, while discordant results of RFR and resting Pd/Pa did not result in worse outcomes compared with negative RFR and resting Pd/Pa. ConclusionThe combined assessment of FFR with RFR and resting Pd/Pa stratified TVF risks in vessels with intermediate coronary stenosis.

The uric acid/HDL-C ratio may predict significant coronary stenosis in moderate left main coronary artery lesions: an intravascular ultrasonography study

BackgroundThere may be severe difficulties in determining the severity of LMCA (left main coronary artery) lesions. The use of intravascular ultrasound (IVUS) facilitates decisions about lesion severity in these patients. The aim of this study was to investigate the relationship between the UHR (uric acid to HDL-C ratio) and lesion severity in patients who underwent LMCA IVUS.MethodsThis study included 205 patients with ICS (intermediate coronary stenosis) in the LMCA who underwent IVUS. In the IVUS measurements of these patients, the plaque burden (PB) and the minimal lumen area (MLA) showing lesion severity were measured.ResultsThe patients were separated into two groups according to plaque burden (< 65% and ≥ 65%). The UHR was significantly greater in the high plaque burden group (479.5 vs. 428.6, P = 0.001). When the patients were separated into two groups according to the MLA (< 6mm2 and ≥ 6mm2), the UHR was determined to be significantly greater in the group with low MLA (476.8 vs. 414.9, P < 0.001). In the ROC analysis performed according to the MLA and plaque burden values, the UHR cutoff value of 450 was found to have similar sensitivity and the same specificity for both parameters.ConclusionsThe results of this study suggested that there is a relationship between UHR and MLA < 6mm2 and plaque burden ≥ 65%, which are independently evaluated as critical in IVUS, and this could predict anatomically significant lesions in patients with a moderate degree of LMCA stricture.

Rapid and Precise Computation of Fractional Flow Reserve from Routine Two-Dimensional Coronary Angiograms Based on Fluid Mechanics: The Pilot FFR2D Study.

Objective: To present a novel pipeline for rapid and precise computation of fractional flow reserve from an analysis of routine two-dimensional coronary angiograms based on fluid mechanics equations (FFR2D). Material and methods: This was a pilot analytical study that was designed to assess the diagnostic performance of FFR2D versus the gold standard of FFR (threshold ≤ 0.80) measured with a pressure wire for the physiological assessment of intermediate coronary artery stenoses. In a single academic center, consecutive patients referred for diagnostic coronary angiography and potential revascularization between 1 September 2020 and 1 September 2022 were screened for eligibility. Routine two-dimensional angiograms at optimal viewing angles with minimal overlap and/or foreshortening were segmented semi-automatically to derive the vascular geometry of intermediate coronary lesions, and nonlinear pressure-flow mathematical relationships were applied to compute FFR2D. Results: Some 88 consecutive patients with a single intermediate coronary artery lesion were analyzed (LAD n = 74, RCA n = 9 and LCX n = 5; percent diameter stenosis of 45.7 ± 11.0%). The computed FFR2D was on average 0.821 ± 0.048 and correlated well with invasive FFR (r = 0.68, p < 0.001). There was very good agreement between FFR2D and invasive-wire FFR with minimal measurement bias (mean difference: 0.000 ± 0.048). The overall accuracy of FFR2D for diagnosing a critical epicardial artery stenosis was 90.9% (80 cases classified correctly out of 88 in total). FFR2D identified 24 true positives, 56 true negatives, 4 false positives, and 4 false negatives and predicted FFR ≤ 0.80 with a sensitivity of 85.7%, specificity of 93.3%, positive likelihood ratio of 13.0, and negative likelihood ratio of 0.15. FFR2D had a significantly better discriminatory capacity (area under the ROC curve: 0.95 [95% CI: 0.91-0.99]) compared to 50%DS on 2D-QCA (area under the ROC curve: 0.70 [95% CI: 0.59-0.82]; p = 0.0001) in predicting wire FFR ≤ 0.80. The median time of image analysis was 2 min and the median time of computation of the FFR2D results was 0.1 s. Conclusion: FFR2D may rapidly derive a precise image-based metric of fractional flow reserve with high diagnostic accuracy based on a single two-dimensional coronary angiogram.

Cardiovascular Imaging for Coronary Artery Disease in Patients with Diabetes Mellitus.

In patients with diabetes mellitus, accelerated progression of atherosclerosis can lead to worse clinical outcomes. Determining the best diagnostic strategy to identify patients with increased cardiovascular risk is challenging. Current guidelines recommend using both functional imaging and CT angiography to detect myocardial ischemia and coronary artery disease based on pre-test probability. Functional imaging is suggested for patients with a higher clinical likelihood due to its higher rule-in diagnostic capacity. On the other hand, CT angiography is preferred for patients with lower pre-test probability because of its excellent negative predictive value. The optimal management strategy for asymptomatic diabetic patients remains unclear. In asymptomatic diabetic patients, previous randomized trials have not shown benefits from diagnostic testing over standard care. However, these trials were methodologically inconsistent and lacked clear stratification of cardiovascular risk. In terms of invasive evaluation, a combined invasive functional and anatomic imaging approach for angiographically intermediate coronary stenosis appears to be the best, most effective decision pathway for managing diabetic patients.

Renal Dysfunction Increases Risk of Adverse Cardiovascular Events in 5-Year Follow-Up Study of Intermediate Coronary Artery Lesions.

BACKGROUND Progression of chronic coronary syndrome (CCS) is influenced by chronic kidney disease (CKD). This 5-year follow-up study aimed to assess 100 patients with 118 intermediate coronary artery lesions evaluated by fractional flow reserve (FFR) and intravascular imaging stratified according to renal function. MATERIAL AND METHODS This prospective study enrolled patients with intermediate coronary stenosis identified by coronary angiogram. Patients with severe renal dysfunction (estimated glomerular filtration rate (eGFR) <45 ml/min/1.73 m²) were excluded from the study. The remaining were divided into 2 groups according to eGFR: 45-60 ml/min/1.73 m² for mild-to-moderate renal dysfunction and >60 ml/min/1.73 m² for no renal dysfunction. We analyzed intermediate-grade stenoses (40-80% as assessed in coronary angiography) with the use of optical coherence tomography (OCT), FFR, and intravascular ultrasound (IVUS). RESULTS Renal dysfunction patients were older (67.7±8.1 vs 63.6±9.7 years, P=0.044). Lesion characteristics, including plaque type and minimal lumen area in OCT, showed no significant differences between the renal dysfunction and no renal dysfunction groups. Thin-cap fibroatheroma, calcific plaques, lipidic plaques, and fibrous plaques had similar prevalence. FFR values and IVUS parameters did not significantly differ between the groups. Over a 5-year follow-up, individuals with mild-to-moderate renal dysfunction had an elevated risk of all-cause mortality and major adverse cardiovascular events in multivariate analyses adjusted for age and sex. CONCLUSIONS Mild-to-moderate renal dysfunction was not associated with significant differences in OCT- and IVUS-derived plaque morphology nor with functional indices characterizing intermediate-grade coronary stenoses. Renal dysfunction was related to a higher risk of all-cause mortality and major adverse cardiovascular events prevalence in 5-year follow-up.

Impact of calcification on Murray law-based quantitative flow ratio for physiological assessment of intermediate coronary stenoses.

To investigate the influence of coronary calcification on the diagnostic performance of Murray law-based quantitative flow ratio (μQFR) in identifying hemodynamically significant coronary lesions referenced to fractional flow reserve (FFR). A total of 571 intermediate lesions from 534 consecutive patients (66.1 ± 10.0 years, 67.2% males) who underwent coronary angiography and simultaneous FFR measurement were included. Calcific deposits were graded by angiography as none or mild (spots), moderate (involving ≤ 50% of the reference vessel diameter), and severe (> 50%). Performance of μQFR to detect functional ischemia (FFR ≤ 0.80) was evaluated, including diagnostic parameters and areas under the receiver-operating curves (AUCs). The discrimination of ischemia by μQFR was comparable between none/mild and moderate/severe calcification (AUC: 0.91 [95% confidence interval: 0.88-0.93] vs. 0.87 [95% confidence interval: 0.78-0.94]; p = 0.442). No statistically significant difference was observed for μQFR between the two categories in sensitivity (0.70 vs. 0.69, p = 0.861) and specificity (0.94 vs. 0.90, p = 0.192). Moreover, μQFR showed significantly higher AUCs than quantitative coronary angiographic diameter stenosis in both vessels with none/mild (0.91 vs. 0.78, p < 0.001) and moderate/severe calcification (0.87 vs. 0.69, p < 0.001). By multivariable analysis, there was no association between calcification and μQFR-FFR discordance (adjusted odds ratio: 1.529, 95% confidence interval: 0.788-2.968, p = 0.210) after adjustment for other confounding factors. μQFR demonstrated robust and superior diagnostic performance for lesion-specific ischemia compared with angiography alone regardless of coronary calcification.