Quantitative Flow Ratio In Patients Research Articles

Prognostic role of post-percutaneous coronary intervention quantitative flow ratio

Abstract Background/Introduction Accumulated evidence supports the prognostic value of post–percutaneous coronary intervention (PCI) physiological measurement. Quantitative Flow Ratio (QFR) is a well-studied angiography-based method for functional assessment. Purpose To investigate the possible prognostic implications of post-PCI QFR in patients undergoing revascularization. Methods We performed offline QFR analysis in all-comers undergoing PCI in a single center. A cut-off value of 0.8 was used to classify patients in high post-PCI QFR group (>0.8) and low post-PCI QFR group (≤0.8). Patients with at least one vessel with post-PCI QFR ≤0.8 were classified in the low post-PCI QFR group. Primary endpoint was the composite outcome of death, myocardial infraction, ischemia-driven revascularization, and heart failure-related hospitalization. Results We included 297 patients in the study. Mean age was 64 (±11) years and 81% of patients were male. Number of patients presented with chronic coronary syndrome was comparable to that of patients presented with acute coronary syndrome (52.9 vs 47.1 %, respectively). Patients in the low post-PCI QFR group had more often diabetes mellitus, lower left ventricular ejection fraction (LVEF) and higher SYNTAX score compared to patients in the high post-PCI QFR group. Median follow-up period was 29 (26-34) months. After adjusting for covariates, low post-PCI QFR was independently associated with higher rate of the composite outcome (HR: 2.22 95% CI 1.01-4.88, p=0.047). Conclusions In our study, patients with lower post-PCI value were independently associated with higher risk of cardiovascular adverse events.

TCT-717 Prognostic Implications of Residual Global Quantitative Flow Ratio in Patients With Coronary Heart Disease After Percutaneous Coronary Intervention

TCT-717 Prognostic Implications of Residual Global Quantitative Flow Ratio in Patients With Coronary Heart Disease After Percutaneous Coronary Intervention

TCT-292 Prognostic Value of Quantitative Flow Ratio in Patients Undergoing Primary Valve Surgery Combined With Coronary Artery Disease

TCT-292 Prognostic Value of Quantitative Flow Ratio in Patients Undergoing Primary Valve Surgery Combined With Coronary Artery Disease

Diagnostic accuracy of quantitative flow ratio in patients with arrhythmias.

Diagnostic accuracy of quantitative flow ratio in patients with arrhythmias.

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

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. 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. 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). 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.

Diagnostic accuracy of Murray law-based quantitative flow ratio in patients with severe aortic stenosis undergoing transcatheter aortic valve replacement.

Murray law-based quantitative flow ratio (μQFR) is a novel computational method that enables accurate estimation of fractional flow reserve (FFR) using a single angiographic projection. However, its diagnostic value in patients with severe aortic stenosis (AS) remains unclear. We included 25 consecutive patients who underwent transcatheter aortic valve replacement (TAVR) for severe AS with intermediate or greater (30-90%) coronary artery disease (CAD). Pre- and post-TAVR μQFR, QFR, instantaneous flow reserve (iFR), and post-TAVR invasive FFR values were measured. We evaluated the diagnostic performance of pre-TAVR μQFR, QFR, and iFR using post-TAVR FFR ≤ 0.80 as a reference standard of ischemia. Pre-TAVR μQFR was significantly correlated with post-TAVR FFR (r = 0.73, p < 0.0001). The area under the curve of pre-TAVR μQFR on post-TAVR FFR ≤ 0.8 was 0.91 (95% confidence interval [CI] 0.77-0.98), comparable to that of pre-TAVR iFR (0.86 [95% CI 0.71-0.98], p = 0.97). The accuracy, sensitivity, specificity, and positive and negative predictive values of pre-TAVR μQFR on post-TAVR FFR ≤ 0.8 were 84.2% (95% CI 68.7-93.4), 61.6% (95% CI 31.6-86.1), 96.0% (95% CI 79.6-99.9), 88.9% (95% CI 52.9-98.3), and 82.8% (95% CI 70.6-90.6), respectively. For pre-TAVR iFR, these values were 76.5% (95% CI 58.8-89.3), 90.9% (95% CI 58.7-99.8), 69.6% (95% CI 47.1-86.8), 58.8% (95% CI 42.8-73.1), and 94.1% (95% CI 70.8-99.1), respectively. μQFR could be useful for the physiological evaluation of patients with severe AS with concomitant CAD.

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

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. 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). 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. 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.

Effect of hemoglobin A1c management levels on coronary physiology evaluated by quantitative flow ratio in patients who underwent percutaneous coronary intervention.

The coronary physiology and prognosis of patients with different hemoglobin A1c (HbA1c) levels after percutaneous coronary intervention (PCI) are currently unknown. The aim of this study was to assess the effect of different levels of HbA1c control on coronary physiology in patients who underwent PCI for coronary heart disease combined with type 2 diabetes mellitus by quantitative flow ratio (QFR). Patients who successfully underwent PCI and completed 1-year coronary angiographic follow up were enrolled, clinical data were collected, and QFR at immediate and 1-year follow up after PCI was retrospectively analyzed. A total of 257 patients (361 vessels) were finally enrolled and divided into the hemoglobin A1c (HbA1c)-compliance group (103 patients, 138 vessels) and non-HbA1c-compliance group (154 patients, 223 vessels) according to the HbA1c cut-off value of 7%. We compared the results of QFR analysis and clinical outcomes between the two groups. At 1-year follow up after PCI, the QFR was significantly higher (0.94 ± 0.07 vs 0.92 ± 0.10, P = 0.019) and declined less (0.014 ± 0.066 vs 0.033 ± 0.095, P = 0.029) in the HbA1c-compliance group. Meanwhile, the incidence of physiological restenosis was lower in the HbA1c-compliance group (2.9% vs 8.5%, P = 0.034). Additionally, the target vessel revascularization rate was lower in the HbA1c-compliance group (6.8% vs 16.9%, P = 0.018). Furthermore, HbA1c ≥7% (OR 2.113, 95% confidence interval 1.081-4.128, P = 0.029) and QFR decline (OR 2.215, 95% confidence interval 1.147-4.277, P = 0.018) were independent risk factors for target vessel revascularization. Patients with well-controlled HbA1c levels have better coronary physiological benefits and the incidence of adverse clinical outcome events might be reduced.

Diagnostic performance of quantitative flow ratio in non-ST elevation acute coronary syndromes in comparison to non-hyperemic pressure ratios: a prospective study.

Quantitative flow ratio (QFR) is a new angiography-based coronary physiology tool aimed to evaluate functional relevance of intermediate coronary lesions. Aim of the study is to assess diagnostic performance of QFR in patients with non-ST-elevation acute coronary syndrome (NSTE-ACS) in comparison to currently used non-hyperaemic pressure ratios (NHPRs). In this prospective, single-centre study, coronary physiology of intermediate coronary stenoses of non-culprit vessels in patients presenting with NSTE-ACS was evaluated using NHPRs (iFR, DFR or RFR). Subsequently, QFR was computed offline by a QFR analyst blinded to the NHPR results. Diagnostic performance of QFR was assessed in comparison to NHPRs as reference standard. A total of 60 vessels with intermediate coronary stenoses was investigated. The NHPRs were used as follows: RFR 38%, DFR 47% and iFR 15% of the cases. The NHPR result was positive, showing significant lesion, in 19 cases. A significant correlation was found between NHPR and QFR (r = 0.84, p < 0.001). Classification agreement of the two methods (95%) and diagnostic performance of QFR in comparison to NHPR (AUC: 0.962 [0.914-1.00]) were both high. Sensitivity, specificity, positive and negative predictive value of QFR in comparison to NHPR were 84.2%, 100%, 100% and 93.2% respectively. QFR has high diagnostic performance in detecting functionally significant lesions of non-culprit arteries in patients with NSTE-ACS and multivessel disease. Due to its high negative predictive value, it can be used to safely avoid unnecessary invasive physiological assessment of these lesions.

TCT-151 Diagnostic Accuracy of Murray Law–Based Quantitative Flow Ratio in Patients With Severe Aortic Stenosis Undergoing Transcatheter Aortic Valve Replacement

TCT-151 Diagnostic Accuracy of Murray Law–Based Quantitative Flow Ratio in Patients With Severe Aortic Stenosis Undergoing Transcatheter Aortic Valve Replacement

Relationships Between Inflammatory Parameters Derived From Complete Blood Count and Quantitative Flow Ratio in Patients With Stable Coronary Artery Disease.

To investigate the relationships between inflammatory parameters, including neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), monocyte-to-lymphocyte ratio (MLR) and systemic immune-inflammation index (SII), and quantitative flow ratio (QFR) in stable coronary artery disease (CAD) patients (n = 450) enrolled in this cross-sectional study. Logistic regression was performed to evaluate the associations of NLR, PLR, MLR, and SII evaluated as continuous and binary variables with QFR ≤0.80. When treated as continuous variables, lnNLR was associated with QFR ≤0.80 with borderline significance in univariable (odds ratio (OR) = 1.60, p = .05) and multivariable analysis (OR = 1.72, p = .05), while lnMLR was associated with QFR ≤0.80 significantly in univariable analysis (OR = 1.87, p = .03) and with borderline significance in multivariable analysis (OR = 1.91, p = .05). When treated as binary variables, high levels of MLR and SII were significantly associated with QFR ≤0.80 in univariable (MLR: OR = 1.91, p = .02; SII: OR = 2.42, p = .006) and multivariable analysis (MLR: OR = 1.83, p = .04; SII: OR = 2.19, p = .02). NLR, MLR, and SII, but not PLR, were significantly associated with the severity of coronary physiology in stable CAD patients.

Prognostic value of quantitative flow ratio in patients with coronary heart disease after percutaneous coronary intervention therapy: a meta-analysis.

Coronary atherosclerotic heart disease is one of the most serious health and life-threatening diseases. There is no doubt that despite the increasing number of assessment methods used clinically, the prognosis assessment is still not ideal, and newer assessment methods are needed. To investigate the predictive value of quantitative flow ratio (QFR) for adverse events (vessel-oriented composite endpoint events/target lesion failure) in patients after percutaneous coronary intervention (PCI). Eight studies involving 4,173 patients (5,688 vascular lesions) were included. These are studies on the relationship between QFR values and prognosis of adverse cardiac events after PCI. This meta-analysis was performed after quality assessment and data extraction of clinical trials data that met the inclusion criteria. Each of the eight studies described the cut-off values for the best predictive ability of post-PCI QFR and the hazard ratio (HR) between QFR values and adverse events, respectively. The pooled HR of these studies was 4.72 (95% CI: 3.29-6.75). Concurrently, lower post-PCI QFR values were associated with the occurrence of individual clinical events (cardiac death/myocardial infarction/target vessel revascularization), with relative risk values of 6.51 (95% CI: 4.96-8.53), 4.83 (95% CI: 3.08-7.57), and 4.21 (95% CI: 2.66-6.68), respectively. QFR may have great potential in the assessment of prognosis. It is necessary to measure QFR value after PCI. A lower QFR value after PCI was an important predictor for experiencing adverse events.

Comparison Of Fractional Flow Reserve Derived From Computed Tomography And Angiographic Quantitative Flow Ratio In Patients With Stable Chest Pain

Comparison Of Fractional Flow Reserve Derived From Computed Tomography And Angiographic Quantitative Flow Ratio In Patients With Stable Chest Pain

Triglyceride-glucose index is associated with quantitative flow ratio in patients with acute ST-elevation myocardial infarction after percutaneous coronary intervention.

BackgroundThe triglyceride-glucose (TyG) index is a novel marker representing the degree of insulin resistance (IR) and is closely related to cardiovascular diseases. However, the association between the TyG index and vascular function in patients with acute ST-elevation myocardial infarction (STEMI) after percutaneous coronary intervention (PCI) remains unknown.Materials and methodsThis study was a post hoc analysis of a multicenter, prospective cohort study. In this study, patients with STEMI who underwent PCI were included, and coronary angiography data were analyzed by Quantitative coronary angiography (QCA) and quantitative flow ratio (QFR). In addition, the TyG index was calculated as follows: Ln [fasting triglyceride (mg/dl) × fasting blood glucose (mg/dl) × 1/2]. According to the post-PCI QFR, patients were divided into two groups: post-PCI QFR ≤ 0.92 group and post-PCI QFR > 0.92 group. Construction of logistic regression model to explore the relationship between the TyG index and post-PCI QFR.ResultsA total of 241 STEMI patients were included in this study. Compared with patients in the post-PCI QFR > 0.92 group, the TyG index was higher in the post-PCI QFR ≤ 0.92 group. Logistic regression model showed that after adjusting for other confounding factors, the TyG index was positively correlated with the risk of post-PCI QFR ≤ 0.92 (OR = 1.697, 95% CI 1.171–2.460, P = 0.005). Restricted cubic splines showed the cutoff value of TyG index associated with post-PCI QFR ≤ 0.92 risk was 9.75.ConclusionThe TyG index was associated with the risk of post-PCI QFR ≤ 0.92 in STEMI patients. The risk of post-PCI QFR ≤ 0.92 increased when the TyG index exceeded 9.75.

Impact of diabetes on coronary physiology evaluated by quantitative flow ratio in patients who underwent percutaneous coronary intervention.

ABSTRACTAims/IntroductionThere are mixed opinions on the influence of diabetes on the prognosis of patients receiving percutaneous coronary intervention (PCI). Therefore, in this study, the quantitative flow ratio (QFR), an emerging technology of functional evaluation, was used to explore the impact of diabetes on coronary physiology in patients who underwent PCI.Materials and MethodsPatients who underwent successful PCI and a 1‐year angiographic follow up were retrospectively screened and analyzed by the QFR. Based on the presence or absence of diabetes, 677 enrolled patients (794 vessels) were classified into a diabetes group (211 patients, 261 vessels) and a non‐diabetes group (466 patients, 533 vessels). The results of QFR analysis and clinical outcomes were compared between the two groups.ResultsThe two groups reached a similar level of post‐PCI QFR (0.95 ± 0.09 vs 0.96 ± 0.06, P = 0.292). However, at the 1‐year follow up, the QFR was lower (0.93 ± 0.11 vs 0.96 ± 0.07, P < 0.001), and the degree of QFR decline was more obvious (−0.024 ± 0.090 vs −0.008 ± 0.070, P = 0.023) in the diabetes group. Additionally, diabetes was independently associated with functional restenosis (odds ratio 2.164, 95% confidence interval 1.210–3.870, P = 0.009) and target vessel failure (odds ratio 2.654, 95% confidence interval 1.405–5.012, P = 0.003).ConclusionAs evaluated by the QFR, patients with diabetes received less coronary physiological benefit from PCI, which was consistent with their clinical outcomes.

Effects of diabetes mellitus on post-intervention coronary physiological assessment derived by quantitative flow ratio in patients with coronary artery disease underwent percutaneous coronary intervention

AimsTo compare the prognostic implication of post-percutaneous coronary intervention (PCI) quantitative flow ratio (QFR) assessment in patients with and without diabetes enrolled in the all-comers, multicenter, randomized controlled PANDA III trial. MethodsAll treated vessels in PANDA III trial were retrospectively assessed for post-PCI QFR. Vessels with available post-PCI QFR were further stratified into DM and non-DM cohorts, and prognostic performance of post-PCI QFR was compared in 2 cohorts. The primary outcome was 2-year vessel-oriented composite endpoint (VOCE), defined as composite of vessel-related cardiac death, vessel-related non-procedural myocardial infarction, and ischemia-driven target vessel revascularization. ResultsOf 2,989 treated vessels, 2,227 (74.5%) with available post-PCI QFR were included, while 548 were presence of DM and 1,679 were not. The performance of post-PCI QFR to predict 2-year VOCE were moderate in both DM (area under the curve [AUC] 0.77, 95% confidence interval [CI]: 0.68 to 0.87) and non-DM cohorts (AUC 0.74, 95% CI: 0.67 to 0.82), while between-cohorts AUC difference was not significant (ΔAUC 0.03, P = 0.65). After multivariate adjustment, vessels with suboptimal post-PCI QFR results (≤0.92) were associated with higher risk of 2-year VOCE in both DM (adjusted HR 6.24, 95% CI: 2.40 to 16.2) and non-DM cohorts (adjusted HR 5.92, 95% CI: 3.28 to 10.7) without significant interaction (P for interaction 0.91). ConclusionsThis study, the first to directly compare clinical value of post-PCI QFR assessments in patients with and without DM, showed that a higher post-PCI QFR value was associated with improved long-term prognosis regardless of the presence of DM.Clinical Trial Registration Information URL: https://www.clinicaltrials.gov; Unique identifier: NCT02017275.

Relationship Between Immunoinflammation and Coronary Physiology Evaluated by Quantitative Flow Ratio in Patients With Coronary Artery Disease.

Background: The association between coronary physiology and immunoinflammation has not been investigated. We performed a retrospective study using quantitative flow ratio (QFR) to evaluate the interaction between immunoinflammatory biomarkers and coronary physiology.Methods: A total of 172 patients with CAD who underwent coronary arteriography (CAG) and QFR were continuously enrolled from May 2020 to February 2021. As a quantitative indicator of coronary physiology, QFR can reflect the functional severity of coronary artery stenosis. The target vessel measured by QFR was defined as that with the most severe lesions. Significant coronary anatomical stenosis was defined as 70% stenosis in the target vessel.Results: Compared with the QFR > 0.8 group, interleukin (IL)-6, IL-10, tumor necrosis factor (TNF)-α, and interferon (IFN)-γ were increased and CD3+ and CD4+ T lymphocyte counts were decreased in the QFR ≤ 0.8 group. In addition, patients with DS ≤ 70% had higher IL-6, IL-10, and TNF-α levels and decreased CD3+ and CD4+ T lymphocyte counts than those with DS > 70%. Logistic regression analysis indicated IL-6 to be an independent predictor of significant coronary functional and anatomic stenosis (odds ratio, 1.125; 95% CI, 1.059–1.196; P < 0.001). Receiver operating characteristic (ROC) analyses showed that IL-6 > 6.36 was predictive of QFR ≤ 0.8 of the target vessel. The combination of IL-6, IL-10 and CD4 improved the value for predicting QFR ≤ 0.8 of the target vessel (AUC, 0.737; 95% CI, 0.661–0.810).Conclusion: Among immunoinflammatory biomarkers, IL-6 was independently associated with a higher risk of QFR ≤ 0.8 of the target vessel. The combination of immunoinflammatory biomarkers was highly predictive of significant coronary functional and anatomic stenosis.

Sex Differences in the Non-infarct-Related Artery-Based Quantitative Flow Ratio in Patients With ST-Elevation Myocardial Infarction: A Retrospective Study.

Introduction: It has been reported that sex has well-established relationships with the prevalence of coronary artery disease (CAD) and the major adverse cardiovascular events. Compared with men, the difference of coronary artery and myocardial characteristics in women has effects on anatomical and functional evaluations. Quantitative flow ratio (QFR) has been shown to be effective in assessing the hemodynamic relevance of lesions in stable coronary disease. However, its suitability in acute myocardial infarction patients is unknown. This study aimed to evaluate the sex differences in the non-infarct-related artery (NIRA)-based QFR in patients with ST-elevation myocardial infarction (STEMI).Methods: In this study, 353 patients with STEMI who underwent angiographic cQFR assessment and interventional therapy were included. According to contrast-flow QFR (cQFR) standard operating procedures: reliable software was used to modeling the hyperemic flow velocity derived from coronary angiography in the absence of pharmacologically induced hyperemia. 353 patients were divided into two groups according to sex. A cQFR ≤0.80 was considered hemodynamically significant, whereas invasive coronary angiography (ICA) luminal stenosis ≥50% was considered obstructive. Demographics, clinical data, NIRA-related anatomy, and functional cQFR values were recorded. Clinical outcomes included the NIRA reclassification rate between men and women, according to the ICA and cQFR assessments.Results: Women were older and had a higher body mass index (BMI) than men. The levels of diastolic blood pressure, troponin I, peak creatine kinase-MB, low-density lipoprotein cholesterol, N terminal pro B-type natriuretic peptide, stent diameter, and current smoking rate were found to be significantly lower in the female group than in the male group. Women had a lower likelihood of a positive cQFR ≤0.80 for the same degree of stenosis and a lower rate of NIRA revascularization. Independent predictors of positive cQFR included male sex and diameter stenosis (DS) >70%.Conclusions: cQFR values differ between the sexes, as women have a higher cQFR value for the same degree of stenosis. The findings suggest that QFR variations by sex require specific interpretation, as these differences may affect therapeutic decision-making and clinical outcomes.

Serial changes in the quantitative flow ratio in patients with intermediate residual stenosis after percutaneous coronary intervention.

A beneficial surrogate marker for evaluating the effect of medical therapy is warranted to avoid deferred lesion revascularization. Similar to coronary artery imaging for monitoring the effects of medical therapy by analyzing plaque regression and stabilization, we hypothesized that evaluation of serial changes in the quantitative flow ratio (QFR) would serve as a surrogate marker of the effects of medical therapy against deferred lesion revascularization. Here, we investigated serial changes in QFR over time after percutaneous coronary intervention in patients who underwent medical therapy as a secondary prevention. Patients with intermediate stenosis in an untreated vessel observed at the baseline (BL) coronary angiography and follow-up (FU) coronary angiography performed 6-18months after BL angiography were screened in 2 centers. A total of 52 patients were able to analyze both BL and FU QFR. The median QFR was 0.83 (IQR, 0.69, 0.89) at BL and 0.80 (IQR, 0.70, 0.86) at FU. The number of positive ΔQFR and negative ΔQFR were 21 and 31, respectively. The median ΔQFR was 0.05 (IQR, 0.03, 0.09) in positive ΔQFR and - 0.05 (IQR, - 0.07, - 0.03) in negative ΔQFR (p < 0.0001). Univariate and multivariate analyses revealed that LDL-C at FU predicted improvement in the QFR (OR 0.95, 95% confidence interval [0.91, 0.98], P = 0.001). Assessment of serial changes in the QFR may serve as a surrogate marker for the effects of medical therapy in patients with residual intermediate coronary stenosis.

Effect of Low-Density Lipoprotein Cholesterol Goal Achievement on Vascular Physiology Evaluated by Quantitative Flow Ratio in Patients Who Underwent Percutaneous Coronary Intervention.

Purpose: The change in coronary physiology from lipid-lowering therapy (LLT) lacks an appropriate method of examination. Quantitative flow ratio (QFR) is a novel angiography-based approach allowing rapid assessment of coronary physiology. This study sought to determine the impact of low-density lipoprotein cholesterol (LDL-C) goal achievement on coronary physiology through QFR.Methods: Cases involving percutaneous coronary intervention (PCI) and 1-year angiographic follow-up were screened and assessed by QFR analysis. Patients were divided into two groups according to the LDL-C level at the 1-year follow-up: (1) goal-achievement group (LDL-C < 1.8 mmol/L or reduction of ≥50%, n = 146, lesion = 165) and (2) non-achievement group (n = 286, lesion = 331). All QFR data and major adverse cardiovascular and cerebrovascular events (MACCEs) at 1 year were compared between groups.Results: No differences between the groups in quantitative coronary angiography (QCA) data or QFR post-PCI were found. At the 1-year follow-up, lower percentage diameter stenosis (DS%) and percentage area stenosis (AS%) were recorded in the goal-achievement group (27.89 ± 10.16 vs. 30.93 ± 12.03, p = 0.010, 36.57 ± 16.12 vs. 41.68 ± 17.39, p = 0.003, respectively). Additionally, a better change in QFR was found in the goal-achievement group (0.003 ± 0.068 vs. −0.018 ± 0.086, p = 0.007), with a lower incidence of physiological restenosis and MACCEs (2.1 vs. 8.4%, p = 0.018, 5.4 vs. 12.6%, p = 0.021, respectively).Conclusion: Evaluated by QFR, patients who achieved the LDL-C goal appear to have a better coronary physiological benefit. This group of patients also has a better clinical outcome.