Assessment Of Intermediate Coronary Stenosis Research Articles

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.

Advanced CT measures of coronary artery disease with intermediate stenosis in patients with severe aortic valve stenosis

BackgroundCoronary artery disease (CAD) and severe aortic valve stenosis (AS) frequently coexist. While pre-transcatheter aortic valve replacement (TAVR) computed tomography angiography (CTA) allows to rule out obstructive CAD, interpreting hemodynamic significance of intermediate stenoses is challenging. This study investigates the incremental value of CT-derived fractional flow reserve (CT-FFR), quantitative coronary plaque characteristics (e.g., stenosis degree, plaque volume, and composition), and peri-coronary adipose tissue (PCAT) density to detect hemodynamically significant lesions among those with AS and CAD.Materials and methodsWe included patients with severe AS and intermediate coronary lesions (20–80% diameter stenosis) who underwent pre-TAVR CTA and invasive coronary angiogram (ICA) with resting full-cycle ratio (RFR) assessment between 08/16 and 04/22. CTA image analysis included assessment of CT-FFR, quantitative coronary plaque analysis, and PCAT density. Coronary lesions with RFR ≤ 0.89 indicated hemodynamic significance as reference standard.ResultsOverall, 87 patients (age 77.9 ± 7.4 years, 38% female) with 95 intermediate coronary artery lesions were included. CT-FFR showed good discriminatory capacity (area under receiver operator curve (AUC) = 0.89, 95% confidence interval (CI) 0.81–0.96, p < 0.001) to identify hemodynamically significant lesions, superior to anatomical assessment, plaque morphology, and PCAT density. Plaque composition and PCAT density did not differ between lesions with and without hemodynamic significance. Univariable and multivariable analyses revealed CT-FFR as the only predictor for functionally significant lesions (odds ratio 1.28 (95% CI 1.17–1.43), p < 0.001). Overall, CT-FFR ≤ 0.80 showed diagnostic accuracy, sensitivity, and specificity of 88.4% (95%CI 80.2–94.1), 78.5% (95%CI 63.2–89.7), and 96.2% (95%CI 87.0–99.5), respectively.ConclusionCT-FFR was superior to CT anatomical, plaque morphology, and PCAT assessment to detect functionally significant stenoses in patients with severe AS.Clinical relevance statementCT-derived fractional flow reserve in patients with severe aortic valve stenosis may be a useful tool for non-invasive hemodynamic assessment of intermediate coronary lesions, while CT anatomical, plaque morphology, and peri-coronary adipose tissue assessment have no incremental or additional benefit. These findings might help to reduce pre-transcatheter aortic valve replacement invasive coronary angiogram.Key Points• Interpreting the hemodynamic significance of intermediate coronary stenoses is challenging in pre-transcatheter aortic valve replacement CT.• CT-derived fractional flow reserve (CT-FFR) has a good discriminatory capacity in the identification of hemodynamically significant coronary lesions.• CT-derived anatomical, plaque morphology, and peri-coronary adipose tissue assessment did not improve the diagnostic capability of CT-FFR in the hemodynamic assessment of intermediate coronary stenoses.

Exploring the Predictors of the Discrepancy Between Quantitative Flow Ratio and Fractional Flow Reserve Measurements.

Quantitative flow ratio is a novel technology for the functional assessment of intermediate coronary stenoses. The authors sought to explore the influence of diabetes mellitus on the application of quantitative flow ratio and predictors of discrepancies between quantitative flow ratio and fractional flow reserve. Quantitative flow ratio was calculated in 224 patients (317 vessels) who underwent fractional flow reserve measurement by professional technicians blinded to fractional flow reserve value. Patients were divided into the diabetes mellitus group and the non-diabetes mellitus group. The diagnostic performance of quantitative flow ratio was assessed using fractional flow reserve as a reference. Good correlation and agreement between quantitative flow ratio and fractional flow reserve can be found in the diabetes mellitus group (r = 0.834, P <.001; mean difference: 0.007 ± 0.108). Prior myocardial infarction showed a statistically significant association with increased classification discrepancy between quantitative flow ratio and fractional flow reserve (odds ratio 3.16 (95% confidence interval: 1.29-7.75), P =.01). The area under the receiver-operating characteristic curve of quantitative flow ratio showed no significant difference in diabetes mellitus and non-diabetes mellitus groups, hemoglobin A1c ≥ 7% and hemoglobin A1c < 7% groups, diabetic duration ≥ 10 years and diabetic duration < 10 years groups (area under receiver-operating characteristic curve: 0.90 (95% confidence interval: 0.84-0.94) vs. 0.92 (95% confidence interval: 0.87-0.96), P =.54; 0.89 (95% confidence interval: 0.81-0.95) vs. 0.92 (95% confidence interval: 0.81-0.97), P =.65; 0.88 (95% confidence interval: 0.79-0.94) vs. 0.89 (95% confidence interval: 0.79-0.96), P =.83; respectively). Clinical application of quantitative flow ratio is not limited to diabetic patients. The relationship between prior myocardial infarction and quantitative flow ratio needs to be further developed.

Abstract 13438: Resource Utilization and Outcome Trends of Intravascular Physiologic Testing During Percutaneous Coronary Intervention - United States National Inpatient Database Analysis 2014 Through 2019

Introduction: Physiologic assessment of intermediate coronary stenosis has shown superiority in guiding decision making when compared to angiographic assessment alone. Many recent trials have shown improved outcomes using resting or hyperemic indices for severity assessment. In this study, we aimed to analyze the trends of intravascular physiologic testing during percutaneous coronary intervention (PCI), adjusted in-hospital mortality, adjusted in-hospital stay and adjusted hospital cost. Methods: Data were extracted from the National Inpatient Sample (NIS) 2014 through 2019 Database. The NIS was searched for PCI with and without intravascular physiologic testing in adult patients (age ≥18) using ICD 9 and 10 codes. Outcomes of interest were utilization rates of intravascular physiologic testing during PCI, trend of adjusted in-hospital mortality, adjusted mean LOS and adjusted mean hospital cost. Multivariate logistic and linear regression analysis was used accordingly to adjust for confounders. STATA software was used for analysis. Results: Of 2,871,865 PCIs in 2014 through 2019, 118,795 (4.1%) were coupled with intravascular physiologic testing. The use of intravascular physiologic testing during PCI steadily increased from 2.8% in 2014 to 5.0% in 2019 (trend p &lt;0.001). The adjusted in-hospital mortality for PCI with physiologic testing did not show any significant statistical linear trend through the years (0.8% in 2014 vs. 0.9% in 2019, trend p=0.123). The mean adjusted LOS remained the same (3 days, trend p=0.530), whereas, mean adjusted hospital cost showed a linear trend of higher hospital cost (24033$ in 2014 vs. 25434$ in 2019, trend p=0.014). Conclusions: There is a rise in use of coronary intravascular physiologic testing during PCI. No statistically significant linear trend was observed in terms of in-hospital mortality or LOS for PCI with intravascular physiologic testing, however, over the years the mean hospital cost is on the rise.

Clinical assessment of resting full-cycle ratio and fractional flow reserve for coronary artery disease in a real-world cohort.

There are few reports published on the comparison of the resting full-cycle ratio (RFR) and fractional flow reserve (FFR) on the assessment of the severity of coronary stenosis. We aimed to investigate the diagnostic accuracy of RFR for detection of functionally significant coronary lesions. This was an observational, retrospective, single-center study. We evaluated both RFR and FFR for 277 coronary lesions of 235 patients who underwent coronary angiography. Patients presenting with chronic coronary syndrome, unstable angina, or non-ST-elevation myocardial infarction were included. The mean FFR and RFR values were 0.84 ± 0.08 and 0.90 ± 0.08, respectively. RFR significantly correlated with FFR (r = 0.727, P < 0.001). The agreement rate between the FFR and RFR was 79.8% (221/277). The diagnostic performance of RFR vs. FFR was accuracy 79.8%, sensitivity 70.4%, specificity 83.7%, positive predictive value 64.0%, and negative predictive value 87.2%. The discriminative power of RFR to identify lesions with FFR ≤ 0.80 was acceptable when the RFR value was within the gray zone [0.86 ≤ RFR ≤ 0.93; AUC: 0.72 (95% CI:0.63-0.81)], while it was excellent when the RFR value was out of the gray zone [RFR > 0.93 or < 0.86; AUC: 0.94 (95% CI:0.88-0.99)]. RFR was significantly correlated with FFR in the assessment of intermediate coronary stenosis. An RFR-FFR hybrid approach increases the diagnostic accuracy of RFR in the detection of functionally significant lesions.

Comparison of efficacy and safety of intracoronary nicardipine and adenosine for fractional flow reserve assessment of coronary stenosis

BackgroundAdministration of intracoronary (IC) adenosine allows an easily feasible, inexpensive, and more rapid alternative method for fractional flow reserve (FFR). It is common practice in many centers worldwide. Nicardipine is a strong coronary vasodilator but its efficacy and safety for assessing FFR is not established. The purpose of present study was to compare the efficacy and safety of IC nicardipine and adenosine for assessing FFR. MethodsOne hundred and fifty-nine patients with a total of 193 vessels undergoing clinically indicated FFR assessment of intermediate coronary stenoses were included. For the initial assessment of FFR, hyperemia was induced by an IC adenosine. After a washout period of 3 min, FFR was reassessed using 200 μg of IC nicardipine. ResultsHyperemic efficacy among two different stimuli was compared. The mean FFR with IC adenosine was 0.83 ± 0.09 and that with an IC nicardipine was 0.84 ± 0.09. The median FFR with an IC adenosine was 0.83 (0.78–0.91) and that with an IC nicardipine was 0.85 (0.79–0.91) (p-value 0.246). Both FFR values showed an excellent correlation (R2 = 0.982, p < 0.001). Nicardipine produced fewer changes in heart rate, less chest pain and less flushing than adenosine. Transient atrioventricular block occurred in 29 patients with IC adenosine and none with IC nicardipine. ConclusionsIC bolus injection of nicardipine could be introduced as a safe and practical alternative method of inducing hyperemia during FFR measurements. Compared to IC adenosine, IC nicardipine has a similar hyperemic efficacy and excellent side-effect profile.

Diagnostic performance and limitation of quantitative flow ratio for functional assessment of intermediate coronary stenosis

BackgroundThis study aimed to simultaneously investigate diagnostic performance and limitation of quantitative flow reserve (QFR) for assessing functionally significant coronary stenosis, focusing on factors affecting diagnostic accuracy of QFR. MethodsThis study evaluated 1) QFR diagnostic accuracy compared with fractional flow reserve (FFR) in patients with stable coronary artery disease (Cohort-A, n = 95) and 2) QFR reproducibility for non-culprit lesions (NCLs) assessment between acute and staged (14±5 days later) procedures in patients with ST-segment elevation myocardial infarction (STEMI) (Cohort-B, n = 65). All coronary angiography image acquisition was performed before the introduction of QFR system into our institution. ResultsCohort-A showed good correlation (r = 0.80, p<0.0001) between QFR and FFR; diagnostic accuracy of QFR for FFR ≤0.80 was 85.2% (sensitivity 80.4%, specificity 91.0%, positive predictive value 91.1%, negative predictive value 80.0%). There were 14 lesions showing discordance between QFR and FFR, which was primarily attributable to inadequate lesion visualization due to vessel overlap/tortuosity and/or insufficient intra-coronary contrast-media injection. In Cohort-B, there was also excellent correlation between acute and staged QFR; classification agreement of acute and staged QFR was 92.3%. Five lesions showed discordance between acute and staged QFR, 4 were due to limited image acquisition and/or high coronary flow velocity at acute phase of STEMI and 1 was borderline ischemia. ConclusionsQFR-derived physiological assessment of intermediate coronary stenosis is feasible, even in the acute setting of STEMI. Adjusting some technical factors may further improve the diagnostic performance of QFR.

Borderline coronary lesion assessment with quantitative flow ratio and its relation to the instantaneous wave-free ratio

PurposeQuantitative flow ratio (QFR) is a recently developed image-based index for the assessment of borderline coronary artery disease. We sought to investigate a correlation between QFR and instantaneous wave-free ratio (iFR) for the assessment of intermediate coronary stenoses. Materials and methodsPatients with borderline coronary lesions (40–90% by visual assessment) undergoing iFR assessment were enrolled. QFR was derived from a modeled hyperemic flow velocity derived from angiography without adenosine-induced hyperemia. Pressure wire-derived iFR served as the reference. ResultsValues of QFR and iFR from 110 vessels with a mean percent diameter stenosis of 44.6 ​± ​12.0% were compared. Mean iFR was 0.90 ​± ​0.07 and 38 (34.5%) had iFR ≤0.89. Mean QFR was 0.81 ​± ​0.10 and 44 (40%) had QFR ≤0.80. A good agreement between QFR and iFR measurements was confirmed with a mean difference of 0.09 (95%CI -0.027 to 0.207) and intraclass correlation coefficient of 0.87 (95%CI 0.81–0.91). The overall diagnostic accuracy (AUC in ROC analysis) of QFR in detecting iFR ≤0.89 was 0.87 (95%CI 0.79–0.93; p ​< ​0.001). Regarding iFR ≤0.89, the optimal cutoff value of QFR was 0.79 with sensitivity, specificity, and accuracy of 76.3%, 83.3%, and 80.0%, respectively. A 100% sensitivity was observed for a QFR cutoff value of 0.88 and a 100% specificity for a QFR cutoff value of 0.69. ConclusionsOur study confirmed good QFR diagnostic performance and correlation with iFR for detecting the functional ischemia caused by intermediate lesions in coronary arteries. However, the pressure wire assessment with iFR might be warranted in 2/3 of patients after QFR assessment.

Valuation of Resting Full Cycle Ratio (RFR) in Comparison with Fractional Flow Reserve (FFR) in Assessment of Intermediate Coronary Stenosis, A Prospective Single Center Evaluation

valuation of Resting Full Cycle Ratio (RFR) in Comparison with Fractional Flow Reserve (FFR) in Assessment of Intermediate Coronary Stenosis, A Prospective Single Center Evaluation

P2720Diagnostic accuracy of Quantitative Flow Ratio (QFR) and Vessel Fractional Flow Reserve (vFFR) compared to Fractional Flow Reserve (FFR) based on 7.5 frames/second coronary angiography

Abstract Background Fractional flow reserve (FFR) is the gold standard for the physiological assessment of intermediate coronary artery lesions. Recently, several novel methods for computation of FFR based on 3-dimensional quantitative coronary angiography have been developed. These techniques allow analyses to be performed retrospectively and do not require induction of hyperaemia. The development and validation of these techniques are based on good quality coronary angiography with high frames per second (15 fps) acquisition. The diagnostic accuracy of Quantitative Flow Ratio (QFR) and Vessel Fractional Flow Reserve (vFFR) in real world “radiation-save mode” coronary angiography has not been studied. Purpose To validate the accuracy of QFR and vFFR compared to FFR based on a series of coronary angiography acquired at 7.5 fps. Methods We retrospectively analyzed 134 vessels (102 patients) with intermediate coronary artery stenosis (30–90%) in whom an FFR measurement had been performed. All the coronary angiography were acquired at 7.5 fps. 33 vessels (20 patients) were excluded from the study due to unsuitable coronary anatomy, invalid FFR measurements, poor image quality and lack of 2 projections ≥25° apart. A total of 101 vessels (82 patients) were included in the final analysis. Contrast-QFR (cQFR), fixed-QFR (fQFR) and vFFR analysis were performed in these vessels by two independent trained experts blinded to the FFR readings. FFR measurements at hyperaemic steady state was taken as the gold standard reference. Results Good intra- and inter-observer reliability was noted for fQFR, cQFR and vFFR analysis (intra-observer mean difference for fQFR: 0.016±0.060, p=0.066; cQFR: 0.009±0.053, p=0.230; vFFR: 0.008±0.040, p=0.175; inter-observer mean difference for fQFR: 0.001±0.036, p=0.847; cQFR: −0.001±0.049; p=0.910, vFFR: −0.005±0.037, p=0.393). fQFR and cQFR showed good correlation with FFR (r=0.694, p&lt;0.001 and r=0.674, p&lt;0.001, respectively) while vFFR showed moderate correlation with FFR (r=0.388, p&lt;0.001). Similarly, fQFR and cQFR showed good accuracy for the detection of functionally significant coronary stenosis (fQFR AUC 0.882 (95% CI 0.803–0.938) and cQFR AUC 0.886 (95% CI 0.807–0.940)) while vFFR showed moderate accuracy with AUC 0.719 (95% CI 0.621–0.804). For identifying functionally significant stenosis (FFR ≤0.80), the overall diagnostic accuracy were 81.2%, 85.2%, 75.3% for fQFR, cQFR and vFFR, repectively. The sensitivity and specificity were 72.7%, 89.9% (fQFR); 83.5%, 31.8% (cQFR) and 68.2%, 87.3% (vFFR). Conclusion Functional assessment of intermediate coronary stenosis based on 7.5 fps angiography-derived computational modelling is feasible. Our study shows that fQFR and cQFR have a better diagnostic accuracy for detecting functionally significant coronary stenosis compared to vFFR. At the lower radiation-save mode 7.5 fps angiography, cQFR does not appear to provide additional diagnostic accuracy compared to fQFR.

Comparison of resting and adenosine-free pressure indices with adenosine-induced hyperemic fractional flow reserve in intermediate coronary lesions

ObjectiveFractional flow reserve (FFR) using adenosine has been the gold standard in the functional assessment of intermediate coronary stenoses in the catheterization laboratory. We aim to study the correlation of adenosine-free indices such as whole cycle Pd/Pa [the ratio of mean distal coronary pressure (Pd) to the mean pressure observed in the aorta (Pa)], instantaneous wave-free ratio (iFR), and contrast-induced submaximal hyperemia (cFFR) with FFR. MethodsThis multicenter, prospective, observational study included patients with stable angina or acute coronary syndrome (>48 h since onset) with discrete intermediate coronary lesions (40–70% diameter stenosis). All patients underwent assessment of whole cycle Pd/Pa, iFR, cFFR, and FFR. We then evaluated the correlation of these indices with FFR and assessed the diagnostic efficiencies of them against FFR ≤0.80. ResultsOf the 103 patients from three different centers, 83 lesions were included for analysis. The correlation coefficient (r value) of whole cycle Pd/Pa, iFR, and cFFR in relation to FFR were +0.84, +0.77, and +0.70 (all p values < 0.001), respectively, and the c-statistic against FFR ≤0.80 were 0.92 (0.86–0.98), 0.89(0.81–0.97), and 0.91 (0.85–0.97) (all p values < 0.001), respectively. The best cut-off values identified by receiver–operator characteristic curve for whole cycle Pd/Pa, iFR, and cFFR were 0.94, 0.90, and 0.88, respectively, for an FFR ≤0.80. By the concept of “adenosine-free zone” (iFR = 0.86–0.93), 59% lesions in this study would not require adenosine. ConclusionAll the three adenosine-free indices had good correlation with FFR. There is no difference in the diagnostic accuracies among the indices in functional evaluation of discrete intermediate coronary stenoses. However, further validation is needed before adoption of adenosine-free pressure parameters into clinical practice.

Impact of increasing dose of intracoronary adenosine on peak hyperemia duration during fractional flow reserve assessment

BackgroundFractional Flow Reserve (FFR) is currently indicated as a first line strategy for the functional assessment of intermediate coronary stenoses. However, the protocol for inducing hyperemia still lacks standardization. Intracoronary adenosine boli, with a progressive increase to high-dosage, have been proposed as a sensitive and accurate strategy for the classification of coronary stenoses, although being potentially affected by the achievement of plateau of the effect and by a less prolonged and stable hyperemia as compared to intravenous administration. Therefore, the aim of the present study was to define the conditioning parameters and assess the impact of increasing-dose intracoronary adenosine on peak hyperemia duration in patients undergoing FFR for intermediate coronary stenoses. MethodsFFR was assessed in patients with intermediate (40 to 70%) lesions by pressure-recording guidewire (Prime Wire, Volcano), after induction of hyperemia with intracoronary boli of adenosine (from 60 to 1440 μg, with dose doubling at each step). Hyperemic duration was defined as the time for the variation form minimum FFR ± 0.02 and time to recovery till baseline values. ResultsWe included 87 patients, undergoing FFR evaluation of 101 lesions. Mean peak hyperemia duration and time to recovery significantly increased with adenosine doses escalation (p = 0.02 and p < 0.001). Peak hyperemia duration and time to recovery with 1440 μg adenosine were 14.5 ± 12.6 s and 45.2 ± 30.7 s, respectively. Hyperemia duration was not related to Quantitative Coronary Angiography (QCA) parameters or FFR values. In fact, a similar increase in the time of hyperemic peak was noted when comparing patients with positive or negative FFR (pbetween = 0.87) or patients with lesions < or ≥20 mm (pbetween = 0.92) and lesions involving left main coronary or proximal left anterior descending artery (LAD) (pbetween = 0.07). A linear relationship was observed between time to recovery and FFR variations, with a greater time to baseline required in patients with FFR ≤ 0.80 (p = 0.003) and in lesions ≥ 20 mm (p = 0.006), but not in LAD/LM lesions (p = 0.55). ConclusionsThe present study shows a progressive raise in the duration of peak hyperemia and time to recovery, after the administration of increasing doses of intracoronary adenosine for the assessment of FFR. Therefore, considering the potential advantages of a high-dose adenosine protocol, allowing a more prolonged hyperemia and a more precise and reliable measurement of FFR, further larger studies with such FFR strategy should certainly be advocated to confirm its safety and benefits, before its routinely use recommendation.

Experience With an On-Site Coronary Computed Tomography-Derived Fractional Flow Reserve Algorithm for the Assessment of Intermediate Coronary Stenoses

Fractional flow reserve (FFR) derived from coronary computed tomography angiography (CTA) is a new technique for the diagnosis of ischemic coronary artery stenoses. The aim of this prospective study was to evaluate the diagnostic performance of a novel on-site computed tomography-based fractional flow reserve algorithm (CT-FFR) compared with invasive FFR as the gold standard, and to determine whether its diagnostic performance is affected by interobserver variations in lumen segmentation. We enrolled 44 consecutive patients (64.6 ± 8.9 years, 34% female) with 60 coronary atherosclerotic lesions who underwent coronary CTA and invasive coronary angiography in 2 centers. An FFR value ≤0.8 was considered significant. Coronary CTA scans were evaluated by 2 expert readers, who manually adjusted the semiautomated coronary lumen segmentations for effective diameter stenosis (EDS) assessment and on-site CT-FFR simulation. The mean CT-FFR value was 0.77 ± 0.15, whereas the mean EDS was 43.6 ± 16.9%. The sensitivity, specificity, positive predictive value, and negative predictive value of CT-FFR versus EDS with a cutoff of 50% were the following: 91%, 72%, 63%, and 93% versus 52%, 87%, 69%, and 77%, respectively. The on-site CT-FFR demonstrated significantly better diagnostic performance compared with EDS (area under the curve 0.89 vs 0.74, respectively, p <0.001). The CT-FFR areas under the curve of the 2 readers did not show any significant difference (0.89 vs 0.88, p = 0.74). In conclusion, on-site CT-FFR simulation is feasible and has better diagnostic performance than anatomic stenosis assessment. Furthermore, the diagnostic performance of the on-site CT-FFR simulation algorithm does not depend on the readers' semiautomated lumen segmentation adjustments.

Diagnostic accuracy of a hybrid approach of instantaneous wave-free ratio and fractional flow reserve using high-dose intracoronary adenosine to characterize intermediate coronary lesions: Results of the PALS (Practical Assessment of Lesion Severity) prospective study.

We sought to investigate the diagnostic accuracy of instantaneous wave-free ratio (iFR) and high-dose intracoronary adenosine fractional flow reserve (IC-FFR) compared with classical intravenous adenosine fractional flow reserve (IV-FFR) to assess coronary stenosis severity. The usefulness of two hybrid strategies combining iFR and high-dose IC-FFR was also evaluated. Physiological assessment of intermediate coronary stenoses to guide revascularization is currently recommended. Consecutive real-world patients with angiographically intermediate coronary stenosis (40-80% diameter stenosis) were prospectively included in the PALS (Practical Assessment of Lesion Severity) study. In every target lesion iFR, high-dose IC-FFR and IV-FFR were systematically measured to assess the accuracy of an hybrid sequential approach combining iFR and IC-FFR. A total of 106 patients with 121 intermediate coronary lesions were analyzed. Both, iFR and IC-FFR showed a significant correlation with IV-FFR (iFR: r = 0.60, 95%CI 0.48-0.70; IC-FFR: r = 0.88; 95%CI: 0.83-0.92). High-dose IC-FFR provided lower FFR values than IV-FFR (0.81 ± 0.08 vs. 0.82 ± 0.09, P = 0.25). Using a receiver-operating-characteristic curve an optimal iFR threshold of 0.91 for the screening test was identified. A sequential test strategy (initial iFR followed by IC-FFR only in lesions with iFR <0.91) yielded an excellent diagnostic accuracy (96.7%, 95%CI 96.7-99.1%) with a sensitivity, specificity, positive and negative predicted values of 100%, 94.7%, 91.8%, and 100%, respectively. A hybrid approach using the previously described iFR gray zone (0.85-0.94) also provided an excellent diagnostic accuracy (95%, 95%CI: 89.5-98.1%). In patients with intermediate coronary lesions a hybrid strategy by using a sequential approach of iFR and high-dose IC-FFR, provided a very good diagnostic performance to identify physiologically significant stenoses. © 2017 Wiley Periodicals, Inc.

Efficacy of pressure parameters obtained during contrast medium-induced submaximal hyperemia in the functional assessment of intermediate coronary stenosis in comparison with instantaneous wave-free ratio

BackgroundDespite evidence demonstrating the benefits of percutaneous coronary intervention guided by fractional flow reserve (FFR), FFR evaluation has not been widely adopted. We sought to compare the diagnostic performances of instantaneous wave-free ratio (iFR) to a novel contrast medium-induced index in FFR prediction, hypothesizing that the latter parameter would offer superior diagnostic agreement with FFR. Methods & resultsWe studied 132 intermediate stenoses in 97 patients prospectively. iFR was measured first, followed by intracoronary injection of 6mL contrast medium at 3mL/s to obtain end-diastolic instantaneous distal coronary pressure/aortic pressure ratio (Pd/Pa) 60ms before the electrocardiographic R-wave (C-ED-Pd/Pa). Subsequently, conventional hyperemic FFR was measured as a reference standard. Of the 132 lesions, 120 were available for final analysis. The FFR values of 95/120 lesions (79.2%) were between 0.60 and 0.90. C-ED-Pd/Pa values (median 0.79 [interquartile range 0.69–0.87]) were significantly lower than FFR values (0.81 [0.75–0.88], P<0.01), whereas iFR values (0.91 [0.86–0.94], P<0.01) were significantly higher. Correlation coefficients with FFR were 0.78 (standard error of the estimate [SEE] 0.067, P<0.0001) and 0.93 (SEE 0.052, P<0.0001) for iFR and C-ED-Pd/Pa, respectively (P<0.001). The areas under the receiver operating characteristic curves were 0.88 and 0.96 for iFR and C-ED-Pd/Pa, respectively (P<0.01). Diagnostic accuracy was 85.0% and 92.5% for iFR and C-ED-Pd/Pa, respectively (P=0.06). ConclusionsC-ED-Pd/Pa is a novel, practical, and accurate measure for the physiological assessment of intermediate coronary stenosis compared to iFR.

TCT-163 Physiologic Assessment of Intermediate Coronary Artery Stenosis by Intravascular Ultrasound Radiofrequency Signal Analysis of Blood Speckles: A Comparison with Fractional Flow Reserve and Instantaneous Wave-Free Ratio

Although fractional flow reserve (FFR) is the gold standard in functional assessment of intermediate coronary stenosis, it lacks anatomical information essential for risk stratification of plaque and guidance of PCI. In IVUS, integrated backscatter (IB) values of blood speckles, calculated as the

Diagnostic cutoff for pressure drop coefficient in relation to fractional flow reserve and coronary flow reserve: A patient-level analysis.

Functional assessment of intermediate coronary stenosis during cardiac catheterization is conducted using diagnostic parameters like fractional flow reserve (FFR), coronary flow reserve (CFR), hyperemic stenosis resistance index (HSR), and hyperemic microvascular resistance (HMR). CDP (ratio of pressure drop across a stenosis to distal dynamic pressure), a nondimensional index derived from fundamental fluid dynamic principles, based on a combination of intracoronary pressure, and flow measurements may improve the functional assessment of coronary lesion severity. Patient-level data pertaining to 350 intracoronary pressure and flow measurements across coronary stenoses was assessed to evaluate CFR, FFR, HSR, HMR, and CDP. CDP was calculated as (ΔP)/(0.5 × ρ × APV(2)). The density of blood (ρ) was assumed to be 1.05 g/cm(3). The correlation of current diagnostic parameters (CFR, FFR, HSR, and HMR) with CDP was evaluated. The receiver operating characteristic (ROC) curve was used to identify the optimal cut-off point of CDP, corresponding to the clinically used cut-off values (FFR = 0.80 and CFR = 2.0). CDP correlated significantly with FFR (r = 0.81, P < 0.05) and had significant diagnostic efficiency (ROC-area under curve of 86%), specificity (72%) and sensitivity (85%) at FFR < 0.8. The corresponding cut-off value for CDP to detect FFR < 0.8 was at CDP>25.4. CDP also correlated significantly (r = 0.98, P < 0.05) with epicardial-specific parameter, HSR. CDP, a functional parameter based on both intracoronary pressure and flow measurements, has close agreement (area under ROC curve = 86%) with FFR, the frequently used method of evaluating stenosis severity.

Efficacy of pressure parameters obtained during contrast medium-induced submaximal hyperemia in the functional assessment of intermediate coronary stenosis

BackgroundDespite evidence demonstrating the superiority of percutaneous coronary intervention guided by fractional flow reserve (FFR), FFR evaluation has not been widely adopted. We sought to determine the diagnostic performance of baseline conditions and contrast medium-induced pressure indices in predicting FFR. We hypothesized that the contrast medium-induced end-diastolic pressure parameter would offer superior diagnostic agreement with FFR, compared to other indices. Methods & resultsNinety-one intermediate stenoses in 75 patients were studied prospectively. The baseline distal coronary pressure to aortic pressure ratio (Pd/Pa) and end-diastolic instantaneous Pd/Pa 60ms before the electrocardiographic R-wave (ED-Pd/Pa) were measured; then, after intracoronary injection of 6mL contrast medium at 3mL/s, Pd/Pa (C-Pd/Pa) and end-diastolic Pd/Pa (C-ED-Pd/Pa) were obtained. Subsequently, conventional FFR was measured as a reference standard. Of the 91 lesions, 11 (12.1%) were excluded because of suboptimal data acquisition, leaving 80 for final analysis. C-ED-Pd/Pa values (median 0.80 [interquartile range 0.70–0.88]) were significantly lower than conventional FFR (0.83 [0.75–0.89], P<0.01), whereas Pd/Pa (0.93 [0.90–0.96], P<0.01), ED-Pd/Pa (0.91 [0.87–0.93], P<0.01), and C-Pd/Pa (0.85 [0.79–0.90], P<0.05) were significantly higher. Correlation coefficients (R) with conventional FFR were 0.74 (standard error of the estimate [SEE] 0.067, P<0.0001), 0.78 (SEE 0.062, P<0.0001), 0.85 (SEE 0.052, P<0.0001), and 0.93 (SEE 0.037, P<0.0001) for Pd/Pa, ED-Pd/Pa, C-Pd/Pa, and C-ED-Pd/Pa, respectively. Diagnostic accuracy was 81.2%, 83.8%, 87.5% and 93.8% for Pd/Pa, ED-Pd/Pa, C-Pd/Pa, and C-ED-Pd/Pa, respectively. ConclusionsAmong baseline indices and contrast-induced pressure parameters, C-ED-Pd/Pa is a novel, feasible, and high-performance measure for the physiological assessment of intermediate coronary stenosis.

Myocardial perfusion MRI compared to fractional flow reserve: a meta-analysis

Methods This meta-analysis was performed in adherence to the PRISMA statement. Two reviewers systematically searched PubMed, EMBASE and Web of Science, using predefined inclusion and exclusion criteria. Only studies using invasive coronary angiography combined with FFR for assessment of intermediate coronary stenoses were included. The QUADAS-2 criteria were applied for quality appraisal. A random-effects model was used for computing pooled sensitivity, specificity, likelihood ratios, and the diagnostic odds ratio. Analyses were performed on both vessel and patient levels.

Cost Benefit for Assessment of Intermediate Coronary Stenosis with Fractional Flow Reserve in Public and Private Sectors in Australia

Fractional Flow Reserve (FFR) is a proven technology for guiding percutaneous coronary intervention (PCI), but is not reimbursed despite the fact that it is frequently used to defer PCI. Costs incurred with use of FFR were compared in both the public and private sectors with the costs that would have been incurred if the technology was not available using consecutive cases over a two year period in a public teaching hospital and its co-located private hospital. FFR was performed on 143 lesions in 120 patients. FFR was < 0.80 in 37 lesions in 34 patients and 25 underwent PCI while 11 had CABG. It was estimated that without FFR 78 lesions in 70 patients would have had PCI with 17 patients having CABG with 35 additional functional tests. Despite a cost of $A1200 per wire, FFR actually saved money. Mean savings in the public sector were $1200 per patient while in the private sector the savings were $5000 per patient. FFR use saves money for the Federal Government in the public sector and for the Private Health Funds in the private sector. These financial benefits are seen in addition to the improved outcomes seen with this technology.