Dataset on blood flow and instantaneous wave-free ratio in normal and stenosed coronary arteries.
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ABSTRACT:
SUBMITTER: Liu H
PROVIDER: S-EPMC7408341 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:Background Quantitative flow ratio ( QFR ) has a high diagnostic accuracy in assessing functional stenoses relevance, as judged by fractional flow reserve ( FFR ). However, its diagnostic performance has not been thoroughly evaluated using instantaneous wave-free ratio ( iFR ) or coronary flow reserve as the reference standard. This study sought to evaluate the diagnostic performance of QFR using other reference standards beyond FFR . Methods and Results We analyzed 182 patients (253 vessels) with stable ischemic heart disease and 82 patients (105 nonculprit vessels) with acute myocardial infarction in whom coronary stenoses were assessed with FFR , iFR, and coronary flow reserve. Contrast QFR analysis of interrogated vessels was performed in blinded fashion by a core laboratory, and its diagnostic performance was evaluated with respect to the other invasive physiological indices. Mean percentage diameter stenosis, FFR , iFR , coronary flow reserve, and QFR were 53.1±19.0%, 0.80±0.13, 0.88±0.12, 3.14±1.30, and 0.81±0.14, respectively. QFR showed higher correlation ( r=0.863 with FFR versus 0.740 with iFR , P<0.001), diagnostic accuracy (90.8% versus 81.3%, P<0.001), and discriminant function (area under the curve=0.953 versus 0.880, P<0.001) when FFR was used as a reference standard than when iFR was used as the reference standard. However, when coronary flow reserve was used as an independent reference standard, FFR , iFR , and QFR showed modest discriminant function (area under the curve=0.682, 0.765, and 0.677, respectively) and there were no significant differences in diagnostic accuracy among FFR , iFR , and QFR (65.4%, 70.6%, and 64.9%; all P values in pairwise comparisons >0.05, overall comparison P=0.061). Conclusions QFR has a high correlation and agreement with respect to both FFR and iFR , although it is better when FFR is used as the comparator. As a pressure-derived index not depending on wire or adenosine, QFR might be a promising tool for improving the adoption rate of physiology-based revascularization in clinical practice.
| S-EPMC6507214 | biostudies-literature
Project description:OBJECTIVES:The study sought to determine the coronary flow characteristics of angiographically intermediate stenoses classified as discordant by fractional flow reserve (FFR) and instantaneous wave-free ratio (iFR). BACKGROUND:Discordance between FFR and iFR occurs in up to 20% of cases. No comparisons have been reported between the coronary flow characteristics of FFR/iFR discordant and angiographically unobstructed vessels. METHODS:Baseline and hyperemic coronary flow velocity and coronary flow reserve (CFR) were compared across 5 vessel groups: FFR+/iFR+ (108 vessels, n = 91), FFR-/iFR+ (28 vessels, n = 24), FFR+/iFR- (22 vessels, n = 22), FFR-/iFR- (208 vessels, n = 154), and an unobstructed vessel group (201 vessels, n = 153), in a post hoc analysis of the largest combined pressure and Doppler flow velocity registry (IDEAL [Iberian-Dutch-English] collaborators study). RESULTS:FFR disagreed with iFR in 14% (50 of 366). Baseline flow velocity was similar across all 5 vessel groups, including the unobstructed vessel group (p = 0.34 for variance). In FFR+/iFR- discordants, hyperemic flow velocity and CFR were similar to both FFR-/iFR- and unobstructed groups; 37.6 (interquartile range [IQR]: 26.1 to 50.4) cm/s vs. 40.0 [IQR: 29.7 to 52.3] cm/s and 42.2 [IQR: 33.8 to 53.2] cm/s and CFR 2.36 [IQR: 1.93 to 2.81] vs. 2.41 [IQR: 1.84 to 2.94] and 2.50 [IQR: 2.11 to 3.17], respectively (p > 0.05 for all). In FFR-/iFR+ discordants, hyperemic flow velocity, and CFR were similar to the FFR+/iFR+ group; 28.2 (IQR: 20.5 to 39.7) cm/s versus 23.5 (IQR: 16.4 to 34.9) cm/s and CFR 1.44 (IQR: 1.29 to 1.85) versus 1.39 (IQR: 1.06 to 1.88), respectively (p > 0.05 for all). CONCLUSIONS:FFR/iFR disagreement was explained by differences in hyperemic coronary flow velocity. Furthermore, coronary stenoses classified as FFR+/iFR- demonstrated similar coronary flow characteristics to angiographically unobstructed vessels.
| S-EPMC5743106 | biostudies-literature
Project description:OBJECTIVES:To compare fractional flow reserve (FFR) and instantaneous wave-free ratio (iFR) measurements in an all-comer patient population with moderate coronary artery stenoses. BACKGROUND:Visual assessment of the severity of coronary artery stenoses is often discordant in moderate lesions. FFR allows reliable functional severity assessment in these cases but requires adenosine-induced hyperaemia with associated additional time, costs and side effects. The iFR is a hyperaemia-independent index. METHODS AND RESULTS:Between November 2015 and February 2017, 356 consecutive patients were included in whom 515 coronary stenoses were measured using both iFR and FFR. Mean iFR and FFR were 0.90?±?0.09 and 0.86?±?0.08, respectively. iFR correlated well with FFR [r?=?0.75; p?<?0.001]. Receiver operating characteristic analysis identified an area under the curve of 0.92. An iFR-only strategy with a treatment cut-off ?0.89 revealed a diagnostic classification agreement with the FFR-only strategy in 420 lesions (82%) with a sensitivity of 87%, a specificity of 80%, a positive predictive value of 56% and a negative predictive value of 96%. CONCLUSIONS:Real-time iFR measurements have good negative predictive value compared to FFR, but moderate diagnostic accuracy (82%). It exposes fewer patients to adenosine, reduces procedure time and costs. Further prospective trials are needed to evaluate specific clinical settings, cut-off values and endpoints.
| S-EPMC6046658 | biostudies-literature
Project description:Background:Fractional flow reserve (FFR), as a functional measurement of coronary stenosis, is recommended for guiding revascularization in intermediate coronary lesions. However, it still remains underutilized for potential reasons including time consumption, costs, or contraindications associated with adenosine administration. Here we performed this meta-analysis to assess the diagnostic performance of two adenosine-free indices, instantaneous wave free-ratio (iFR), and quantitative flow ratio (QFR) in evaluating coronary stenosis severity with FFR as the reference standard. Methods:PubMed, Embase, and Cochrane Central Register of Controlled Trials (CENTRAL) were searched to include relevant studies with the diagnostic accuracy of iFR or QFR referenced to FFR. A bivariate model was applied to pool diagnostic parameters. We used Cochran's Q test and I2 index to assess heterogeneity and identify the potential source of heterogeneity by meta-regression. Results:A total of 8213 lesions from 28 studies (19 for iFR and 9 for QFR) were included in this meta-analysis. The pooled sensitivity and specificity were 0.79 (95% CI, 0.75 to 0.83) and 0.85 (95% CI, 0.82 to 0.87) for iFR and 0.90 (95% CI, 0.84 to 0.93) and 0.88 (95% CI, 0.86 to 0.90) for QFR, respectively. Significantly higher sensitivity and specificity were observed in the bivariate analysis for QFR than for iFR (P < 0.001 for both). The area under summary receiver-operating curve of iFR and QFR was 0.89 (95% CI, 0.86 to 0.92) and 0.92 (95% CI, 0.89 to 0.94). Conclusion:Evidence suggests that both of the two indices have good performance in detecting functional ischemia of coronary arteries and QFR might be a promising method without requiring the pressure wire. Further application of QFR may potentially provide important information to clinicians in the assessment of coronary lesions.
| S-EPMC6500690 | biostudies-literature
Project description:BackgroundThe instantaneous wave-free ratio (iFR) is a novel method to assess the ischemic potential of coronary artery stenoses. Clinical trial data have shown that iFR has acceptable diagnostic agreement with fractional flow reserve (FFR), the reference standard for the functional assessment of coronary stenoses. This study compares iFR measurements with FFR measurements in a real world, single-center setting.Methods and resultsInstantaneous wave-free ratio and FFR were measured in 50 coronary artery lesions in 42 patients, with FFR ≤ 0.8 classified as functionally significant. An iFR-only technique, using a treatment cut-off value, iFR ≤ 0.89, provided a classification agreement of 84% with FFR ≤ 0.80. Use of a hybrid iFR-FFR technique, incorporating FFR measurement for lesions within the iFR gray zone of 0.86-0.93, would improve classification agreement with FFR to 94%, with diagnosis achieved without the need for hyperemia in 57% patients.ConclusionThis study in a real-world setting demonstrated good classification agreement between iFR and FFR. Use of a hybrid iFR-FFR technique would achieve high diagnostic accuracy while minimizing adenosine use, compared with routine FFR.
| S-EPMC5447668 | biostudies-literature
Project description:BackgroundThere has been a gradual upward creep of revascularization thresholds for both fractional flow reserve (FFR) and instantaneous wave-free ratio (iFR), before the clinical outcome trials for both indices. The increase in revascularization that has potentially resulted is at odds with increasing evidence questioning the benefits of revascularizing stable coronary disease. Using an independent invasive reference standard, this study primarily aimed to define optimal thresholds for FFR and iFR and also aimed to compare the performance of iFR, FFR, and resting distal coronary pressure (Pd)/central aortic pressure (Pa).Methods and resultsPd and Pa were measured in 75 patients undergoing coronary angiography±percutaneous coronary intervention with resting Pd/Pa, iFR, and FFR calculated. Doppler average peak flow velocity was simultaneously measured and hyperemic stenosis resistance calculated as hyperemic stenosis resistance=Pa-Pd/average peak flow velocity (using hyperemic stenosis resistance >0.80 mm Hg/cm per second as invasive reference standard). An FFR threshold of 0.75 had an optimum diagnostic accuracy (84%), whereas for iFR this was 0.86 (76%). At these thresholds, the discordance in classification between indices was 11%. The accuracy of contemporary thresholds (FFR, 0.80; iFR, 0.89) was significantly lower (78.7% and 65.3%, respectively) with a 25% rate of discordance. The optimal threshold for Pd/Pa was 0.88 (77.3% accuracy). When comparing indices at optimal thresholds, FFR showed the best diagnostic performance (area under the curve, 0.91 FFR versus 0.79 iFR and 0.77 Pd/Pa, P=0.002).ConclusionsContemporary thresholds provide suboptimal diagnostic accuracy compared with an FFR threshold of 0.75 and iFR threshold of 0.86 (cutoffs in derivation studies). Whether more rigorous thresholds would result in selecting populations gaining greater symptom and prognostic benefit needs assessing in future trials of physiology-guided revascularization.
| S-EPMC6314449 | biostudies-literature
Project description:The rate pressure product (RPP) is an index of myocardial metabolism that correlates closely with myocardial hemodynamics. The relationship between the RPP and the fractional flow reserve (FFR) and instantaneous wave-free ratio (iFR) is not known. In this study, we investigated the effects of the RPP on the FFR and iFR. We retrospectively enrolled 195 patients (259 lesions) who had undergone invasive coronary angiography and both the iFR and FFR examinations between 2012 and 2017. The RPP was defined as systolic blood pressure multiplied by the heart rate, measured prior to the iFR evaluation. The study population was divided into the low-RPP (n = 129, mean RPP: 6981 ± 1149) and high-RPP (n = 130, mean RPP: 10391 ± 1603) groups according to the median RPP. Correlations and biases between the iFR and FFR were compared. The diagnostic performance of the iFR in the groups was calculated, using FFR as the gold standard. The correlation between the iFR and FFR was higher in the high-RPP group than in the low-RPP group. The bias between the iFR and FFR in the high-RPP group was smaller than that in the low-RPP group. The best cutoff value of the iFR for predicting an FFR of 0.8 was 0.90 for all lesions, 0.93 for the low-RPP group, and 0.82 for the high-RPP group. The iFR and RPP showed a weak but a statistically significant negative correlation (R = 0.14; p = 0.029). This was not observed for the relationship between the FFR and RPP. In conclusion, the RPP affects the relationship between the FFR and iFR. With FFR as the gold standard, the iFR may underestimate and overestimate the functionality of ischemia in the low- and high-RPP groups, respectively.
| S-EPMC7396073 | biostudies-literature
Project description:BackgroundDeferral of coronary revascularization is safe whether guided by instantaneous wave-free ratio (iFR) or by fractional flow reserve (FFR). We aimed to assess long-term outcomes in patients deferred from revascularization based on iFR or FFR in a large real-world population.MethodsFrom 2013 through 2017, 201,933 coronary angiographies were registered in the Swedish Web-System for Enhancement and Development of Evidence-Based Care in Heart Disease Evaluated According to Recommended Therapies (SWEDEHEART). We included all patients (n = 11,324) with at least 1 coronary lesion deferred from PCI during an index procedure using iFR (>0.89; n = 1998) or FFR (>0.80; n = 9326). The primary outcome was major adverse cardiac events (MACE) defined as the composite of all-cause death, nonfatal myocardial infarction, or unplanned revascularization. A multivariable-adjusted Cox proportional hazards model was used, with analysis for interaction of prespecified subgroups.ResultsPatients presented with stable angina pectoris (iFR 46.9% vs FFR 48.6%), unstable angina or non-ST-elevation myocardial infarction (iFR 37.7% vs FFR 33.1%), ST-elevation myocardial infarction (iFR 1.9% vs FFR 1.6%), and other indications (iFR 12.5% vs FFR 15.7%). The median follow-up was 2 years for both iFR and FFR groups. At the conclusion of the study, the cumulative MACE risks were 26.7 for the iFR group and 25.9% for FFR group. In the adjusted analysis, no difference was found between the 2 groups (adjusted hazard ratio: iFR vs FFR, 0.947; 95% CI, 0.84-1.08; P = 39). Consistent with the overall findings, the prespecified subgroups showed no interaction with the FFR/iFR results.ConclusionsDeferral of revascularization showed similar long-term safety whether based on iFR or on FFR.
| S-EPMC11307766 | biostudies-literature
Project description:The assessment of the left main coronary artery (LMCA) by coronary angiography has several limitations. The fractional flow reserve (FFR) is useful for the functional evaluation of LMCA stenoses. The instantaneous wave-free ratio (iFR), a resting index, was developed to simplify functional coronary assessment. However, its performance for LMCA stenoses has yet to be explored. The iFR was measured at rest, and the FFR was measured under maximal hyperemia. We calculated that a sample size of 90 lesions would have provided 90% power at a 5% significance level to detect an Area Under the Curve (AUC) < 0.7 for the iFR to identify FFR-positive stenoses. A total of 91 measurements were performed on angiographically intermediate LMCA stenoses at three centers. The comparison between the iFR and the FFR showed a significant correlation (r = 0.67, p < 0.001). At receiver operating characteristic (ROC) analysis, the iFR revealed a good diagnostic performance when compared to the FFR (AUC = 0.84; p < 0.001). A classification agreement between the iFR and the FFR was recorded in 81% of cases. The left ventricular ejection fraction (LVEF) was an independent predictor of the discrepancy between the FFR and iFR values (p = 0.040). The present study is the first demonstrating that the assessment of LMCA stenoses with the instantaneous wave-free ratio is a reliable adenosine-free alternative to classic fractional flow reserve. If confirmed in larger populations, these findings could be of relevance for real world daily practice.
| S-EPMC6724021 | biostudies-literature
Project description:ObjectivesThe aim of this study was to investigate whether algorithmic interpretation (AI) of instantaneous wave-free ratio (iFR) pressure-wire pull back data would be noninferior to expert human interpretation.BackgroundInterpretation of iFR pressure-wire pull back data can be complex and is subjective.MethodsFifteen human experts interpreted 1,008 iFR pull back traces (691 unique, 317 duplicate). For each trace, experts determined the hemodynamic appropriateness for percutaneous coronary intervention (PCI) and, in such cases, the optimal physiological strategy for PCI. The heart team (HT) interpretation was determined by consensus of the individual expert opinions. The same 1,008 pull back traces were also interpreted algorithmically. The coprimary hypotheses of this study were that AI would be noninferior to the interpretation of the median expert human in determining: 1) the hemodynamic appropriateness for PCI; and 2) the physiological strategy for PCI.ResultsRegarding the hemodynamic appropriateness for PCI, the median expert human demonstrated 89.3% agreement with the HT in comparison with 89.4% for AI (p < 0.01 for noninferiority). Across the 372 cases judged as hemodynamically appropriate for PCI according to the HT, the median expert human demonstrated 88.8% agreement with the HT in comparison with 89.7% for AI (p < 0.0001 for noninferiority). On reproducibility testing, the HT opinion itself changed 1 in 10 times for both the appropriateness for PCI and the physiological PCI strategy. In contrast, AI showed no change.ConclusionsAI of iFR pressure-wire pull back data was noninferior to expert human interpretation in determining both the hemodynamic appropriateness for PCI and the optimal physiological strategy for PCI.
| S-EPMC6645043 | biostudies-literature