Prognostic Value of Quantitative Flow Ratio Combined with SYNTAX Scores I/II in Multivessel Coronary Artery Disease: A Small-Sample, Single-Center Study.

Background: A fractional flow reserve (FFR)-fixed-SYNTAX score could decrease the number of high-risk patients. This study explored the prognostic value of non-invasive quantitative flow ratio (QFR)-fixed-SYNTAX I/II scores in multivessel disease patients. Methods: This was a single-center, small-sample, observational study. Multivessel coronary disease patients were enrolled and finished a 1-year follow-up. SYNTAX scores I/II and functional SYNTAX scores I/II based on QFR (cut-off value of 0.85) were calculated for all patients. The composite occurrence of cardiac deaths, any myocardial infarction, or ischemia-driven revascularization were analyzed using a different score system. Results: A total of 160 patients were stratified into risk groups based on a different scoring system. FSS (functional SYNTAX score) and FSSII (functional SYNTAX score II) reduce the radio of high-risk major adverse cardiovascular events (MACEs), transforming the patients from high-risk to medium- and low-risk. Furthermore, FSSII (hazard ratio (HR): 1.069, 95% CI: 1.025-1.115, p = 0.002) showed a better relationship with MACEs than the other score systems. After recalculating SSII, the survival-free ratio stratified by FSSII decreased from 38.46% to 27.27% in the high-risk group and increased from 84.09% to 86.05% in the low-risk group. Conclusions: FSS or FSSII could decrease the number of high-risk patients compared to SYNTAX score (SS) and FSS. SYNTAX II score (SSII) and FSSII showed a better predictive ability than other scoring systems for under-risk stratification.

Angiography-derived physiological patterns of coronary artery disease: implications with post-stenting physiology and long-term clinical outcomes.

BACKGROUND: Physiological patterns of coronary artery disease (CAD) have emerged as potential determinants of functional results of percutaneous coronary interventions (PCI) and of vessel-oriented clinical outcomes (VOCE). OBJECTIVES: In this study, we evaluated the impact of angiography-derived physiological patterns of CAD on post-PCI functional results and long-term clinical outcomes. METHODS: Pre-PCI angiography-derived fractional flow reserve (FFR) virtual pullbacks were quantitatively interpreted and used to determine the physiological patterns of CAD. Suboptimal post-PCI physiology was defined as an angiography-derived FFR value ≤ 0.91. The primary endpoint was the occurrence of VOCE at the longest available follow-up. RESULTS: Six hundred fifteen lesions from 516 patients were stratified into predominantly focal (n = 322, 52.3%) and predominantly diffuse (n = 293, 47.7%). Diffuse pattern of CAD was associated with lower post-PCI angiography-derived FFR values (0.91 ± 0.05 vs. 0.94 ± 0.05; p = 0.001) and larger rate of suboptimal post-PCI physiology (43.0 vs. 22.7%; p = 0.001), as compared to focal CAD. At the median follow-up time of 37 months (33-58), post-PCI suboptimal physiology was related to a higher risk of VOCE (16.2% vs. 7.6%; HR: 2.311; 95% CI 1.410-3.794; p = 0.0009), while no significant difference was noted according to baseline physiological pattern. In diffuse disease, the use of intracoronary imaging was associated with a lower incidence of long-term VOCE (5.1% vs 14.8%; HR: 0.313, 95% CI 0.167-0.614, p = 0.030). CONCLUSIONS: Suboptimal post-PCI physiology is observed more often in diffusely diseased arteries and it is associated with higher risk of VOCE at follow-up. The use of intravascular imaging might improve clinical outcomes in the setting of diffuse CAD.

Smoking paradox in coronary function and structure of acute ST-segment elevation myocardial infarction patients treated with primary percutaneous coronary intervention.

BACKGROUND: The Smoking paradox has generated inconsistent findings concerning the clinical prognosis of acute ST-segment elevation myocardial infarction (STEMI) patients, while providing limited insights into coronary anatomy and function which are crucial prognostic factors. Therefore, this study aimed to further investigate the existence of smoking paradox in coronary anatomy and function. METHODS: This study divided STEMI patients into smokers and non-smokers. Quantitative coronary angiography, angiography­derived microcirculatory resistance (AMR) and quantitative flow ratio (QFR) were utilized to analyze coronary anatomy and function. These parameters were compared using multivariable analysis and propensity score matching. The clinical outcomes were evaluated using Kaplan-Meier curve and Cox regression. RESULTS: The study included 1258 patients, with 730 in non-smoker group and 528 in smoker group. Smokers were significantly younger, predominantly male, and had fewer comorbidities. Without adjusting for confounders, smokers exhibited larger lumen diameter [2.03(1.45-2.57) vs. 1.90(1.37-2.49), P = 0.033] and lower AMR [244(212-288) vs. 260(218-301), P = 0.006]. After matching and multivariate adjustment, smokers exhibited inversely smaller lumen diameter [1.97(1.38-2.50) vs. 2.15(1.63-2.60), P = 0.002] and higher incidence of coronary microvascular dysfunction [233(53.9%) vs. 190(43.6%), P = 0.002], but showed similar AMR and clinical outcomes compared to non-smokers. There was no difference in QFR between two groups. CONCLUSION: Smoking among STEMI patients undergoing pPCI was associated with smaller lumen diameter and higher occurrence of coronary microvascular dysfunction, although it had no further impact on clinical prognosis. The smoking paradox observed in coronary anatomy or function may be explained by younger age, gender, and lower prevalence of comorbidities.

Assessment of perioperative cardiac risk using preoperative quantitative flow ratio in patients with coronary artery disease undergoing noncardiac surgery: a retrospective cohort study.

Background: Quantitative flow ratio (QFR) is a novel diagnostic modality for the functional testing of coronary artery stenosis, but evidence concerning the postoperative prognostic implication of QFR in noncardiac surgery (NCS) of patients with coronary artery disease (CAD) is limited. The purpose of this study was to examine the role of QFR in perioperative risk prediction in patients with coronary heart disease. Methods: This retrospective cohort study was conducted in The First Affiliated Hospital of Wenzhou Medical University between 2013 and 2022, and consecutively included patients with CAD who had undergone NCS <1 year after coronary angiography. The primary endpoint was major adverse cardiovascular events (MACEs), which were defined as a composite of cardiovascular death, nonfatal myocardial infarction, nonfatal stroke, cardiopulmonary arrest, malignant ventricular arrhythmia (MVA), congestive heart failure, and revascularization. Univariate and multifactorial Cox regression was used to identify the independent risk factors for perioperative cardiovascular events and to construct new models. The area under the curve (AUC), net reclassification improvement (NRI), and integrated discrimination improvement (IDI) were used to compare the newly constructed model with existing traditional models. Results: Among the 929 participants enrolled (median age 68 years; 72.0% male), the primary endpoint was met in 67 (7.2%) patients within 30 days of follow-up. There was no significant difference in the incidence of the primary endpoint between patients with QFR <0.75 and those with "gray zone" lesions (0.75≤ QFR ≤0.8) (log-rank P=0.325). Patients with QFR <0.75 and those with "gray zone" lesions (0.75≤ QFR ≤0.8) had a higher incidence of primary endpoint events compared to patients with QFR >0.8. [QFR <0.75 vs. QFR >0.8: adjusted hazard ratio (HR) =20.70, P<0.001; 0.75≤ QFR ≤0.8 vs. QFR >0.8: HR =15.99, P<0.001]. The independent predictors of MACEs events within 30 days after NCS were albumin level [HR =0.92, 95% confidence interval (CI): 0.87-0.98; P=0.008], emergency surgery (HR =4.12, 95% CI: 1.66-10.23; P=0.002), and QFR ≤0.8 (HR =15.92, 95% CI: 5.96-42.51; P<0.001). In addition, adjusting the original Revised Cardiac Risk Index (RCRI) with QFR ≤0.8 as a risk factor significantly improved the risk stratification of postoperative adverse events, with the adjusted AUC rising from 0.574 to 0.740 (P<0.001). Conclusions: QFR ≤0.8 could independently predict perioperative cardiovascular adverse events in patients with CAD undergoing NCS and improve the predictive value of original predictive index. Gray-zone lesions (0.75≤ QFR ≤0.8) should be actively treated.

Murray law-based quantitative flow ratio for assessment of nonculprit lesions in patients with ST-segment elevation myocardial infarction.

INTRODUCTION: Revascularization of nonculprit arteries in patients with ST-Segment Elevation Myocardial Infarction (STEMI) is now recommended based on several trials. However, the optimal therapeutic strategy of nonculprit lesions remains unknown. Murray law-based Quantitative Flow Ratio (µQFR) is a novel, non-invasive, vasodilator-free method for evaluating the functional severity of coronary artery stenosis, which has potential applications for nonculprit lesion assessment in STEMI patients. MATERIAL AND METHODS: Patients with STEMI who received staged PCI before hospital discharge were enrolled retrospectively. µQFR analyses of nonculprit vessels were performed based on both acute and staged angiography. RESULTS: Eighty-four patients with 110 nonculprit arteries were included. The mean acute µQFR was 0.76 ± 0.18, and the mean staged µQFR was 0.75 ± 0.19. The average period between acute and staged evaluation was 8 days. There was a good correlation (r = 0.719, P < 0.001) between acute µQFR and staged µQFR. The classification agreement was 89.09%. The area under the receiver operator characteristic (ROC) curve for detecting staged µQFR ≤ 0.80 was 0.931. CONCLUSIONS: It is feasible to calculate the µQFR during the acute phase of STEMI patients. Acute µQFR and staged µQFR have a good correlation and agreement. The µQFR could be a valuable method for assessing functional significance of nonculprit arteries in STEMI patients.

Role of S100ß in Unstable Angina Pectoris: Insights from Quantitative Flow Ratio.

BACKGROUND AND OBJECTIVE: Disturbed autonomic nervous system (ANS) may promote inflammatory, immune, and oxidative stress responses, which may increase the risk of acute coronary events. S100ß has been proposed as a biomarker of neuronal injury that would provide an insightful understanding of the crosstalk between the ANS, immune-inflammatory cells, and plaques that drive atherosclerosis. This study investigates the correlation between S100ß, and functional coronary stenosis as determined by quantitative flow ratio (QFR). METHODS: Patients with unstable angina pectoris (UAP) scheduled for coronary angiography and QFR were retrospectively enrolled. Serum S100ß levels were determined by enzyme-linked immunosorbent assay. The Gensini score was used to estimate the extent of atherosclerotic lesions and the cumulative sum of three-vessel QFR (3V-QFR) was calculated to estimate the total atherosclerotic burden. RESULTS: Two hundred thirty-three patients were included in this study. Receiver operator characteristic (ROC) curve indicated that S100ß>33.28 pg/mL predicted functional ischemia in patients with UAP. Multivariate logistic analyses showed that a higher level of S100ß was independently correlated with a functional ischemia-driven target vessel (QFR ≤0.8). This was also closely correlated with the severity of coronary lesions, as measured by the Gensini score (OR = 5.058, 95% CI: 2.912-8.793, p <0.001). According to 3V-QFR, S100ß is inversely associated with total atherosclerosis burden (B = -0.002, p <0.001). CONCLUSIONS: S100ß was elevated in the functional ischemia stages of UAP. It was independently associated with coronary lesion severity as assessed by Gensini score and total atherosclerosis burden as estimated by 3V-QFR in patients with UAP.

An Overview of Computational Coronary Physiology Technologies Based on Medical Imaging and Artificial Intelligence.

This article reviews four new technologies for assessment of coronary hemodynamics based on medical imaging and artificial intelligence, including quantitative flow ratio (QFR), optical flow ratio (OFR), computational fractional flow reserve (CT-FFR) and artificial intelligence (AI)-based instantaneous wave-free ratio (iFR). These technologies use medical imaging such as coronary angiography, computed tomography angiography (CTA), and optical coherence tomography (OCT), to reconstruct three-dimensional vascular models through artificial intelligence algorithms, simulate and calculate hemodynamic parameters in the coronary arteries, and achieve non-invasive and rapid assessment of the functional significance of coronary stenosis. This article details the working principles, advantages such as non-invasiveness, efficiency, accuracy, limitations such as image dependency, and assumption restrictions, of each technology. It also compares and analyzes the image dependency, calculation accuracy, calculation speed, and operation simplicity, of the four technologies. The results show that these technologies are highly consistent with the traditional invasive wire method, and shows distinct advantages in terms of accuracy, reliability, convenience and cost-effectiveness, but there are also factors that affect accuracy. The results of this review demonstrates that AI-based iFR technology is currently one of the most promising technologies. The main challenges and directions for future development are also discussed. These technologies bring new ideas for the non-invasive assessment of coronary artery disease, and are expected to promote the technological progress in this field.

A Visualized Nomogram for Predicting Prognosis in Elderly Patients after Percutaneous Coronary Intervention.

Background: Revascularized patients still experience adverse cardiovascular events. This is particularly true for elderly patients over the age of 65, as they often have more co-morbid vascular conditions. It is important to develop a tool to assist clinicians in comprehensively assessing these patients' prognosis. The objective of this study is to create a comprehensive visual nomogram model combining clinical and physiological assessments to predict outcomes in elderly patients undergoing percutaneous coronary intervention (PCI). Methods: This study is a retrospective investigation of patients who underwent PCI between January 2016 and December 2017. A total of 691 patients with 1461 vessels were randomly divided into a training (n = 483) and a validation set (n = 208). A multivariate Cox regression model was employed using the training set to select variables for constructing a nomogram. The performance of the nomogram was assessed through the receiver operating characteristic curve (ROC) and calibration curves to evaluate its discrimination and predictive accuracy. To further assess the clinical usefulness, Kaplan-Meier curve analysis and landmark analysis were conducted. Results: Independent risk factors, including diabetes mellitus (DM), post-PCI quantitative flow ratio (QFR), previous myocardial infarction (MI), and previous PCI, were contained in the nomogram. The nomogram exhibited a good area under the curve (AUC) ranging from 0.742 to 0.789 in the training set, 0.783 to 0.837 in the validation set, and 0.764 to 0.786 in the entire population. Calibration curves demonstrated a well-fitted curve in all three sets. The Kaplan-Meier curves showed clear separation and the patients with higher scores in the nomogram model exhibited a higher incidence of target vessel revascularization (TVR) (7.99% vs. 1.24% for 2-year, p < 0.001 and 13.54% vs. 2.23% for 5-years, p < 0.001, respectively). Conclusions: This study has developed the visually intuitive nomogram to predict the 2-year and 5-year TVR rates for elderly patients who underwent PCI. This tool provides more accurate and comprehensive healthcare guidance for patients and their physicians.

Quantitative flow ratio or angiography for the assessment of non-culprit lesions in acute coronary syndromes, a randomized trial.

BACKGROUND: Patients undergoing percutaneous coronary intervention for acute coronary syndromes often have multivessel disease (MVD). Quantitative flow ratio (QFR) is an angiography-based technology that may help quantify the functional significance of non-culprit lesions, with the advantage that measurements are possible also once the patient is discharged from the catheterization laboratory. AIM: Our two-center, randomized superiority trial aimed to test whether QFR, as compared to angiography, modifies the rate of non-culprit lesion interventions (primary functional endpoint) and improves the outcomes of patients with acute coronary syndromes and MVD (primary clinical endpoint). METHODS: In total, 202 consecutive patients (64 [56-71] years of age, 160 men) with STEMI (n = 69 (34%)), NSTEMI (n = 94 (47%)), or unstable angina (n = 39 (19%)) and MVD who had undergone successful treatment of all culprit lesions were randomized 1:1 to angiography- vs. QFR-guided delayed revascularization of 246 non-culprit stenoses (1.2/patient). RESULTS: The proportion of patients assigned to percutaneous intervention was not different between groups (angiography group: 45 (45%) vs. QFR: 56 (55%), P = 0.125; relative risk = 0.80 (0.60-1.06)). At 12 months, a primary clinical endpoint event (composite of death, nonfatal myocardial infarction, revascularization, and significant angina) occurred in 24 patients (angiography-guided) and 23 patients (QFR-guided; P = 0.637, HR = 1.16 [0.63-2.15]). None of its components was different between groups. DISCUSSION: QFR guidance based on analysis of images from the primary intervention was not associated with a difference in the rate of non-culprit lesion staged revascularization nor in the 12-month incidence of clinical events in patients with acute coronary syndromes and multivessel disease. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov Registry (NCT04808310).

The association between cardiac T2*BOLD and quantitative flow ratio (QFR) in the diagnosis of stenotic coronary arteries in patients with multi-vessel coronary artery disease.

BACKGROUND: T2*BOLD is based on myocardial deoxyhemoglobin content to reflect the state of myocardial oxygenation. Quantitative flow ratio is a tool for assessing coronary blood flow based on invasive coronary angiography. PURPOSE: This study aimed to evaluate the correlation between T2*BOLD and QFR in the diagnosis of stenotic coronary arteries in patients with multi-vessel coronary artery disease. METHODS: Fifty patients with MVCAD with at least 1 significant coronary artery stenosis (diameter stenosis > 50%) and 21 healthy control subjects underwent coronary angiography combined with QFR measurements and cardiovascular magnetic resonance (CMR). QFR ≤ 0.80 was considered to indicate the presence of hemodynamic obstruction. RESULTS: Totally 60 (54%) obstructive vessels had hemodynamic change. Between stenotic coronary arteries (QFR ≤ 0.8) and normal vessels, T2*BOLD showed AUCs of 0.97, 0.69, and 0.91 for left anterior descending (LAD), left circumflex (LCX) and right coronary (RCA) arteries and PI displayed AUCs of 0.89, 0.77 and 0.90 (all p > 0.05, except for LAD). The AUCs of T2*BOLD between stenotic coronary arteries (QFR > 0.8) and normal vessels were 0.86, 0.72, and 0.85 for LAD, LCX and RCA; while, PI showed AUCs of 0.93, 0.86, and 0.88, respectively (p > 0.05). Moreover, T2*BOLD displayed AUCs of 0.96, 0.74, and 0.91 for coronary arteries as before between coronary arteries with stenosis (QFR ≤ 0.8 and > 0.8), but the mean PI of LAD, LCX and RCA showed no significant differences between them. CONCLUSION: T2* BOLD and QFR have good correlation in diagnosing stenotic coronary arteries with hemodynamic changes in patients with stable multi-vessel CAD. T2* BOLD is superior to semi-quantitative perfusion imaging in analyzing myocardial ischemia without stress.

Preoperative Quantitative Flow Ratio, Intraoperative Transit Time Flow Measurement Parameters, and Their Predictive Value for Short-Term Graft Failure After Coronary Artery Bypass Grafting.

BACKGROUND: Studies on the relationship between the preoperative quantitative flow ratio (QFR) and parameters of intraoperative transit time flow measurement (TTFM) are extremely rare. In addition, the predictive value of QFR and TTFM parameters for early internal mammary artery (IMA) failure after coronary artery bypass grafting still needs to be validated.Methods and Results: We retrospectively collected data from 510 patients who underwent in situ IMA grafting to the left anterior descending (LAD) artery at Fuwai Hospital. Spearman correlation coefficients between preoperative QFR of the LAD artery and intraoperative TTFM parameters of the IMA were -0.13 (P=0.004) for mean graft flow (Qm) and 0.14 (P=0.002) for the pulsatility index (PI). QFR and TTFM exhibited similar and good predictive value for early IMA failure (5.7% at 1 year), and they were better than percentage diameter stenosis (area under the curve 0.749 for QFR, 0.733 for Qm, 0.688 for PI, and 0.524 for percentage diameter stenosis). The optimal cut-off value of QFR was 0.765. Both univariate and multivariable regression analyses revealed that QFR >0.765, Qm ≤15 mL/min, and PI >3.0 independently contributed to early IMA failure. CONCLUSIONS: There were statistically significant correlations between preoperative QFR of the LAD artery and intraoperative TTFM parameters (Qm, PI) of the IMA. Preoperative QFR and intraoperative Qm and PI exhibited excellent predictive value for early IMA failure.

Clinical Value of the Quantitative Flow Ratio to Predict Long-term Target Vessel Failure in Patients with In-stent Restenosis after Drug-coated Balloon Angioplasty.

OBJECTIVE: The study sought to investigate the clinical predictive value of quantitative flow ratio (QFR) for the long-term target vessel failure (TVF) outcome in patients with in-stent restenosis (ISR) by using drug-coated balloon (DCB) treatment after a long-term follow-up. METHODS: This was a retrospective study. A total of 186 patients who underwent DCB angioplasty for ISR in two hospitals from March 2014 to September 2019 were enrolled. The QFR of the entire target vessel was measured offline. The primary endpoint was TVF, including target vessel-cardiac death (TV-CD), target vessel-myocardial infarction (TV-MI), and clinically driven-target vessel revascularization (CD-TVR). RESULTS: The follow-up time was 3.09±1.53 years, and 50 patients had TVF. The QFR immediately after percutaneous coronary intervention (PCI) was significantly lower in the TVF group than in the no-TVF group. Multivariable Cox regression analysis indicated that the QFR immediately after PCI was an excellent predictor for TVF after the long-term follow-up [hazard ratio (HR): 5.15×10-5 (6.13×10-8-0.043); P<0.01]. Receiver-operating characteristic (ROC) curve analysis demonstrated that the optimal cut-off value of the QFR immediately after PCI for predicting the long-term TVF was 0.925 (area under the curve: 0.886, 95% confidence interval: 0.834-0.938; sensitivity: 83.40%, specificity: 88.00; P<0.01). In addition, QFR≤0.925 post-PCI was strongly correlated with the TVF, including TV-MI and CD-TVR (P<0.01). CONCLUSION: The QFR immediately after PCI showed a high predictive value of TVF after a long-term follow-up in ISR patients who underwent DCB angioplasty. A lower QFR immediately after PCI was associated with a worse TVF outcome.

Assessment of Coronary Stenoses for Percutaneous Coronary Intervention: A Systematic Review and Network Meta-Analysis of Randomized Trials.

Evidence regarding the comparative efficacy of the different methods to determine the significance of coronary stenoses in the catheterization laboratory is lacking. We aimed to compare all available methods guiding the decision to perform percutaneous coronary intervention (PCI). We searched Medline, Embase, and CENTRAL until October 5, 2023. We included trials that randomized patients with greater than 30% stenoses who were considered for PCI and reported major adverse cardiovascular events (MACE). We performed a frequentist random-effects network meta-analysis and assessed the certainty of evidence using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach. We included 15 trials with 16,333 participants with a mean weighted follow-up of 34 months. The trials contained a median of 49.3% (interquartile range: 32.6%, 100%) acute coronary syndrome participants. Quantitative flow ratio (QFR) was associated with a decreased risk of MACE compared with coronary angiography (CA) (risk ratio [RR] 0.68, 95% confidence interval [CI] 0.56 to 0.82, high certainty), fractional flow reserve (FFR) (RR 0.73, 95% CI 0.58 to 0.92, moderate certainty), and instantaneous wave-free ratio (iFR) (RR 0.63, 95% CI 0.49 to 0.82, moderate certainty), and ranked first for MACE (88.1% probability of being the best). FFR (RR 0.93, 95% CI 0.82 to 1.06, moderate certainty) and iFR (RR 1.07, 95% CI 0.90 to 1.28, moderate certainty) likely did not decrease the risk of MACE compared with CA. Intravascular imaging may not be associated with a significant decrease in MACE compared with CA (RR 0.85, 95% CI 0.62 to 1.17, low certainty) when used to guide the decision to perform PCI. In conclusion, a decision to perform PCI based on QFR was associated with a decreased risk of MACE compared with CA, FFR, and iFR in a mixed stable coronary disease and acute coronary syndrome population. These hypothesis-generating findings should be validated in large, randomized, head-to-head trials.

A simple angio-based coronary flow assessment of culprit vessels in primary percutaneous coronary intervention is associated with long-term prognosis after ST-segment-elevation myocardial infarction.

BACKGROUND: Despite prompt reperfusion, the risk of adverse clinical outcomes following ST-segment-elevation myocardial infarction (STEMI) remains pronounced, owing partly to suboptimal reperfusion. However, coronary functional evaluation is seldom feasible during primary percutaneous coronary intervention (PPCI). We aimed to examine the clinical implication of a simple coronary assessment based on single-angiographic view (µQFR) during PPCI in discriminating impaired coronary flow and adverse outcomes for STEMI. METHODS: STEMI Patients undergoing successful PPCI were enrolled and followed up prospectively from 4 medical centers in China. Post-PPCI µQFR of culprit vessels were analyzed. The primary outcome was major adverse cardiovascular events (MACE), defined as a composite of cardiac death, non-fatal MI, ischemia-driven target-vessel revascularization and readmission for heart failure. RESULTS: A total of 570 patients with STEMI were enrolled, and post-PCI µQFR was analyzable in 557 (97.7%) patients, with a median of 0.94. Patients with low post-PCI µQFR showed higher incidence of adverse outcomes than those with high µQFR, showing a 2.5-fold increase in the risk for MACE (hazard ratio: 2.51, 95% confidence intervals: 1.33 to 4.72; P = 0.004). Moreover, post-PCI µQFR significantly increased discriminant ability for the occurrence of MACE when added to traditional GRACE risk score for STEMI (integrated discrimination improvement: 0.029; net reclassification index: 0.229; P < 0.05). CONCLUSIONS: A low µQFR of culprit vessel in PPCI is independently associated with worse clinical outcomes in patients with STEMI. The single-angiographic-view-based coronary evaluation is a feasible tool for discriminating poor prognosis and could serve as a valuable complement in risk stratification for STEMI.

Predictive value of the inconsistency between the residual and post-PCI QFR for prognosis in PCI patients.

Introduction: To investigate the prognostic value of the consistency between the residual quantitative flow ratio (QFR) and postpercutaneous coronary intervention (PCI) QFR in patients undergoing revascularization. Methods: This was a single-center, retrospective, observational study. All enrolled patients were divided into five groups according to the ΔQFR (defined as the value of the post-PCI QFR minus the residual QFR): (1) Overanticipated group; (2) Slightly overanticipated group; (3) Consistent group; (4) Slightly underanticipated group; and (5) Underanticipated group. The primary outcome was the 5-year target vessel failure (TVF). Results: A total of 1373 patients were included in the final analysis. The pre-PCI QFR and post-PCI QFR were significantly different among the five groups. TVF within 5 years occurred in 189 patients in all the groups. The incidence of TVF was significantly greater in the underanticipated group than in the consistent group (P = 0.008), whereas no significant differences were found when comparing the underanticipated group with the other three groups. Restricted cubic spline regression analysis showed that the risk of TVF was nonlinearly related to the ΔQFR. A multivariate Cox regression model revealed that a ΔQFR≤ -0.1 was an independent risk factor for TVF. Conclusions: The consistency between the residual QFR and post-PCI QFR may be associated with the long-term prognosis of patients. Patients whose post-PCI QFR is significantly lower than the residual QFR may be at greater risk of TVF. An aggressive PCI strategy for lesions is anticipated to have less functional benefit and may not result in a better clinical outcome.

QFR for the Revascularization of Nonculprit Vessels in MI Patients: Insights From the FIRE Trial.

BACKGROUND: The role of quantitative flow ratio (QFR) in the treatment of nonculprit vessels of patients with myocardial infarction (MI) is a topic of ongoing discussion. OBJECTIVES: This study aimed to investigate the predictive capability of QFR for adverse events and its noninferiority compared to wire-based functional assessment in nonculprit vessels of MI patients. METHODS: The FIRE (Functional Assessment in Elderly MI Patients With Multivessel Disease) trial randomized 1,445 older MI patients to culprit-only (n = 725) or physiology-guided complete revascularization (n = 720). In the culprit-only arm, angiographic projections of nonculprit vessels were prospectively collected, centrally reviewed for QFR computation, and associated with endpoints. In the complete revascularization arm, endpoints were compared between nonculprit vessels investigated with QFR or wire-based functional assessment. The primary endpoint was the vessel-oriented composite endpoint (VOCE) at 1 year. RESULTS: QFR was measured on 903 nonculprit vessels from 685 patients in the culprit-only arm. Overall, 366 (40.5%) nonculprit vessels showed a QFR value ≤0.80, with a significantly higher incidence of VOCEs (22.1% vs 7.1%; P < 0.001). QFR ≤0.80 emerged as an independent predictor of VOCEs (HR: 2.79; 95% CI: 1.64-4.75). In the complete arm, QFR was used in 320 (35.2%) nonculprit vessels to guide revascularization. When compared with propensity-matched nonculprit vessels in which treatment was guided by wire-based functional assessment, no significant difference was observed (HR: 0.57; 95% CI: 0.28-1.15) in VOCEs. CONCLUSIONS: This prespecified subanalysis of the FIRE trial provides evidence supporting the safety and efficacy of QFR-guided interventions for the treatment of nonculprit vessels in MI patients. (Functional Assessment in Elderly MI Patients With Multivessel Disease [FIRE]; NCT03772743).

Three-Year Clinical Impact of Murray Law-Based Quantitative Flow Ratio and OCT- or FFR-Guidance in Angiographically Intermediate Coronary Lesions.

BACKGROUND: The FORZA trial (FFR or OCT Guidance to Revascularize Intermediate Coronary Stenosis Using Angioplasty) prospectively compared the use of fractional flow reserve (FFR) or optical coherence tomography (OCT) for treatment decisions and percutaneous coronary intervention (PCI) optimization in patients with angiographically intermediate coronary lesions. Murray law-based quantitative-flow-ratio (µQFR) is a novel noninvasive method for the computation of FFR. In the present study, we evaluated the clinical impact of µQFR, FFR, or OCT guidance in FORZA trial lesions at 3-year follow-up. METHODS: µQFR was assessed at baseline and, in the case of a decision to intervene, after (FFR- or OCT-guided) PCI. The baseline µQFR was considered the final µQFR for deferred lesions, and post-PCI µQFR value was taken as final for stented lesions. The primary end point was target vessel failure ([TVF]; cardiac death, target-vessel-related myocardial infarction, and target-vessel-revascularization) at a 3-year follow-up. RESULTS: A total of 419 vessels (199 OCT-guided and 220 FFR-guided) were included in the FORZA trial. µQFR was evaluated in 256 deferred lesions and 159 treated lesions (98 OCT-guided PCI and 61 FFR-guided PCI). In treated lesions, post-PCI µQFR was higher in OCT-group compared with FFR-group (median, 0.93 versus 0.91; P=0.023), and the post-PCI µQFR improvement was greater in FFR-group (0.14 versus 0.08; P<0.0001). At 3-year follow-up, OCT- and FFR-guided treatment decisions resulted in comparable TVF rate (6.7% versus 7.9%; P=0.617). Final µQFR was the only predictor of TVF. µQFR ≤0.89 was associated with 3× increase in TVF (11.6% versus 3.7%; P=0.004). PCI was a predictor of higher final µQFR (odds ratio, 0.22 [95% CI, 0.14-0.34]; P<0.001). CONCLUSIONS: In vessels with angiographically intermediate coronary lesions, OCT-guided PCI resulted in comparable clinical outcomes as FFR-guided PCI. µQFR estimated at the end of diagnostic or interventional procedure predicted 3-year TVF. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT01824030.

The relationship between glycemic risk and longitudinal changes in total physiological atherosclerotic burden in patients with coronary artery disease.

Background: The effects of glycemic status on coronary physiology have not been well evaluated. This study aimed to investigate changes in coronary physiology by using angiographic quantitative flow ratio (QFR), and their relationships with diabetes mellitus (DM) and glycemic control status. Methods: This retrospective cohort study included 530 patients who underwent serial coronary angiography (CAG) measurements between January 2016 and December 2021 at Tongji Hospital of Tongji University. Based on baseline and follow-up angiograms, 3-vessel QFR (3V-QFR) measurements were performed. Functional progression of coronary artery disease (CAD) was defined as a change in 3V-QFR (Δ3V-QFR = 3V-QFRfollow-up - 3V-QFRbaseline) ≤-0.05. Univariable and multivariable logistic regression analyses were applied to identify the independent predictors of coronary functional progression. Subgroup analysis according to diabetic status was performed. Results: During a median interval of 12.1 (10.6, 14.3) months between the two QFR measurements, functional progression was observed in 169 (31.9%) patients. Follow-up glycosylated hemoglobin (HbA1c) was predictive of coronary functional progression with an area under the curve (AUC) of 0.599 [95% confidence interval (CI): 0.546-0.651; P<0.001] in the entire population. Additionally, the Δ3V-QFR values were significantly lower in diabetic patients with HbA1c ≥7.0% compared to those with well-controlled HbA1c or non-diabetic patients [-0.03 (-0.09, 0) vs. -0.02 (-0.05, 0.01) vs. -0.02 (-0.05, 0.02); P=0.002]. In a fully adjusted multivariable logistics analysis, higher follow-up HbA1c levels were independently associated with progression in 3V-QFR [odds ratio (OR), 1.263; 95% CI: 1.078-1.479; P=0.004]. Furthermore, this association was particularly strong in diabetic patients (OR, 1.353; 95% CI: 1.082-1.693; P=0.008) compared to patients without DM. Conclusions: Among patients with established CAD, on-treatment HbA1c levels were independently associated with progression in physiological atherosclerotic burden, especially in patients with DM.