Non-invasive Angiographic-based Fractional Flow Reserve:Technical Development,Clinical Implications,and Future Perspectives

New non-and less-invasive techniques have been developed to overcome the procedural and operator related burden of the fractional flow reserve(FFR)for the assessment of potentially significant stenosis in the coronary arteries.Virtual FFR-techniques can obviate the need for the additional flow or pressure wires as used for FFR measurements.This review provides an overview of the developments and validation of the virtual FFR-algorithms,states the challenges,discusses the upcoming clinical trials,and postulates the future role of virtual FFR in the clinical practice.

Fractional flow reserve and non-hyperemic indices:Essential tools for percutaneous coronary interventions

Hemodynamical evaluation of a coronary artery lesion is an important diagnostic step to assess its functional impact.Fractional flow reserve(FFR)received a class IA recommendation from the European Society of Cardiology for the assessment of angiographically moderate stenosis.FFR evaluation of coronary artery disease offers improvement of the therapeutic strategy,deferring unnecessary procedures for lesions with a FFR>0.8,improving patients'management and clinical outcome.Post intervention,an optimal FFR>0.9 post stenting should be reached and>0.8 post drug eluting balloons.Non-hyperemic pressure ratio measurements have been validated in previous studies with a common threshold of 0.89.They might overestimate the hemodynamic significance of some lesions but remain useful whenever hyperemic agents are contraindicated.FFR remains the gold standard reference for invasive assessment of ischemia.We illustrate this review with two cases introducing the possibility to estimate also non-invasively FFR from reconstructed 3-D angiograms by quantitative flow ratio.We conclude introducing a hybrid approach to intermediate lesions(DFR 0.85-0.95)potentially maximizing clinical decision from all measurements.

Fractional flow reserve measured via left internal mammary artery after coronary artery bypass grafting:Two case reports

BACKGROUND The fractional flow reserve(FFR)has made the treatment of coronary heart disease more precise.However,there are few reports on the measurement of FFR via the left internal mammary artery(LIMA).Herein,we described the determination of further treatments by measuring FFR via the LIMA in 2 cases after coronary artery bypass grafting(CABG).CASE SUMMARY Case 1 was a 66-year-old male who was admitted due to“chest tightness after CABG.”The patient underwent CABG 7 years prior due to coronary heart disease.Coronary artery angiography showed complete occlusion of the left anterior descending artery(LAD),and subtotal occlusion of the third segment of the right coronary artery.On arterial angiography,there was 85%stenosis at the distal end of the anastomosis of the LIMA-LAD graft.FFR via LIMA was determined at 0.75.Thus,balloon dilation was performed in Case 1.FFR after balloon dilation was 0.94.Case 2 was a 60-year-old male who was admitted due to“chest tightness after CABG.”The patient underwent CABG 6 years prior due to coronary heart disease.There was 60%segmental stenosis in the middle segment of LAD and 75%anastomotic stenosis.FFR measured via LIMA was 0.83(negative);thus the intervention was not performed.Case 2 was given drug treatments.At the 3-mo follow-up,there was no recurrence of chest tightness or shortness of breath in both cases.They are currently under continual follow-up.CONCLUSION We provided evidence that FFR measurement via grafted blood vessels,especially LIMA,after CABG is a good method to determine the intervention course.

基于CCTA的ΔCT-FFR对重度钙化冠状动脉功能学评估的临床价值分析

目的探讨基于冠状动脉计算机断层扫描血管成像(CCTA)的血流储备分数(CT-FFR)和冠状动脉病变最严重狭窄处的近端与远端CT-FFR测量差值(ΔCT-FFR)对重度钙化冠状动脉功能学评估诊断效能的临床价值。方法收集2018年1月-2019年6月解放军总医院心血管内科收治住院的107例冠心病(CAD)患者的149支血管进行回顾性分析。所有患者住院期间依次进行CCTA、CT-FFR、侵入性冠状动脉造影(ICA)和有创血流储备分数(FFR)检查。以单支冠状动脉钙化积分(CACS)≥100判断为血管水平的重度钙化,根据CACS水平将冠状动脉分为CACS≥100组(n=56)和CACS<100组(n=93)。以FFR≤0.8作为诊断冠状动脉血流动力学异常的“金标准”,ΔCT-FFR定义为冠状动脉病变最严重狭窄处近端与远端CTFFR的测量差值。采用Pearson相关和Bland-Altman图评估血管水平CT-FFR与FFR值的相关性和一致性。通过ΔCT-FFR校正CT-FFR的检测结果,使用Delong检验比较不同诊断方法间受试者工作特征曲线(ROC)的曲线下面积(AUC),在血管水平分析其对重度钙化冠状动脉功能学评估诊断效能的增量价值。结果在血管水平CT-FFR与FFR值具有较好的相关性(CACS≥100组:r=0.71,P<0.01;CACS<100组:r=0.73,P<0.01)和一致性(CACS≥100组:Mean=-0.01,P=0.25;CACS<100组:Mean=0,P=0.96)。与CACS<100组比较,CACS≥100组FFR(0.80±0.08 vs.0.84±0.09,P=0.004)和CT-FFR值(0.81±0.06 vs.0.85±0.06,P<0.001)明显降低,ΔCT-FFR值(0.14±0.06 vs.0.09±0.06,P<0.001)明显增高。与CACS<100组比较,CACS≥100组CT-FFR的诊断效能明显下降[(AUC=0.792,95%CI 0.663~0.889)vs.(AUC=0.929,95%CI 0.856~0.972),P=0.04]。经ΔCT-FFR校正诊断后,CACS≥100组CT-FFR的诊断效能较前明显提高[(AUC=0.876,95%CI 0.760~0.949)vs.(AUC=0.792,95%CI0.663~0.889),P=0.02],与CACS<100组差异无统计学意义(P=0.37)。结论对于重度钙化冠状动脉,经ΔCT-FFR校正后,CT-FFR评估冠状动脉功能学的诊断效能明显提高。

冠状动脉树重建扩大到较小动脉提高FFRCT准确性的研究

目的本研究旨在通过在计算流体动力学(CFD)领域扩展冠脉树来提高基于冠状动脉CT血管成像(coronary CT angiography,CCTA)的血流储备分数(FFR)的准确性。进行了一项观察性研究,以评估将冠状动脉树分析从最小直径1.2mm扩展到0.8 mm的效果。方法对接受CCTA和介入性FFR治疗的患者进行回顾性研究。76名患者符合纳入标准。重建三维冠状动脉树,生成具有不同管腔直径下限(1.2 mm和0.8 mm)的有限元网格。根据Murray定律定义了出口边界条件。应用NKS方法求解CFD控制方程,得到FFRCT。结果在个体患者水平上,将冠状动脉树的最小直径从1.2mm扩大到0.8mm,FFRCT的灵敏度提高了16.7%(P=0.022),这导致四个假阴性病例转变为真阳性病例。ROC曲线的AUC值由0.74增至0.83。此外,NKS方法可以解决在2160个处理器核的情况下,在10.5分钟内将冠状动脉树扩展到0.8 mm管腔直径的计算问题。结论将重建的冠脉扩大到较小的管腔直径可以显著提高FFRCT的敏感性,NKS方法可以为未来的临床应用提供良好的计算时间。

CCTA-AI联合FFR-CT诊断冠状动脉狭窄病变的应用价值研究

目的评估计算机断层扫描血管成像(CCTA)与人工智能(AI)联合心肌灌注分数(FFR-CT)对冠状动脉狭窄病变的诊断价值。方法选择于2022年1月至2023年2月到南阳市中心医院接受诊治的80例疑似冠状动脉狭窄病变患者作为观察对象。所有患者均接受CCTA以及冠状动脉造影(CAG)检查,其检查的间隔时间应在14天内,然后通过AI软件自动对CCTA的图像进行重建和计算,同时计算FFR-CT的数值。计算人工智能辅助的心脏计算机断层扫描(CCTA-AI)联合FFR-CT诊断的敏感度、特异度、准确度、阳性预测值和阴性预测值。结果80例患者经CAG检查确诊,72例患者为冠状动脉狭窄病变,占比为90%;8例患者为非冠状动脉狭窄病变,占比为10%。CCTA-AI联合FFR-CT检查的敏感度、特异度、阳性预测值、阴性预测值、准确度以及AUC值均高于CCTA-AI、FFR-CT单独检查,差异有统计学意义(P<0.05)。结论采用CCTA-AI联合FFR-CT检查诊断冠状动脉狭窄病变具有较高的诊断效能,其敏感度及特异度均得到显著提高。

冠状动脉CT血管成像联合CT-FFR对冠心病心肌缺血影响因素的研究

目的应用冠状动脉CT血管成像(coronary CT angiography,CCTA)联合冠状动脉CT血流储备分数(coronary CT angiography derived fractional flow reserve,CT-FFR)探讨冠心病患者心肌缺血的影像学特征,并探讨冠心病患者心肌缺血的影响因素。方法回顾性选取2023年1月至11月于浙江中医药大学附属杭州市中医院就诊并行CCTA检查的86例患者,根据测量的CT-FFR值将其分为缺血组(CT-FFR≤0.80,45例)与非缺血组(CT-FFR>0.80,41例),比较两组患者的斑块特征,采用多因素Logistic回归分析探讨冠心病患者心肌缺血的影响因素。结果缺血组患者的糖尿病占比显著高于非缺血组(P<0.05)。共有150支冠状动脉显示有斑块,斑块最常见部位为左前降支(114个)。对212个斑块进行分析,其中缺血组68个斑块,非缺血组144个斑块。非缺血组钙化斑块占比显著高于缺血组(P<0.05);缺血组管腔狭窄程度、斑块体积、脂类成分占比、纤维脂类成分体积均显著大于非缺血组,斑块纤维成分体积显著小于非缺血组(P<0.05)。多因素Logistic回归分析结果显示,管腔狭窄程度(OR=1.054,P=0.026)和斑块体积(OR=1.027,P=0.048)均是冠心病患者心肌缺血的的影响因素。结论管腔狭窄程度及斑块体积均是冠心病患者心肌缺血的影响因素,可对此类患者进行针对性的治疗。

Fractional flow reserve: Current applications and overview of the available data

Flow fractional reserve(FFR) allows to evaluate the functional significance of coronary artery lesions, through the ratio of the mean coronary artery pressure after the stenosis to the mean aortic pressure duringmaximum hyperemia. The actual widely accepted cutoff value is 0.80. Below this value a coronary lesion is considered significant and therefore it requires invasive revascularization. Several studies [in particular Fractional Flow Reserve vs Angiography for Multivessel Evaluation 1(FAME-1) and FAME-2] have shown the relationship between FFR measurement and hard end-points(death, myocardial infarction, and urgent revascularization). Consequently, FFR evaluation represents the cornerstone in the decision-making in intermediate coronary lesions. Recent studies paved the way for further applications of FFR evaluation in complex and tricky clinical settings. In this paper, we perform an overview of the data regarding contemporary application of FFR. In particular, we review the use of FFR in: left main intermediate stenoses, serial stenoses, evaluation after stenting, guidance in coronary artery bypass surgery, and acute coronary syndrome. All the data presented in our overview confirm the essential role of FFR assessment in the daily clinical practice. The shift from "operator-dependent" to "FFR-dependent" evaluation in intermediate coronary artery stenosis is of paramount importance in order to improve the prognosis of our patients, through the discrimination of the functional role of every single coronary stenosis.

Long-term outcomes after fractional flow reserve-guided percutaneous coronary intervention in patients with severe coronary stenosis

Objective To explore the safety and efficacy of FFR-guided percutaneous coronary intervention (PCI) in vessels with severe diameter stenosis. Methods & Results Of 1090 patients undergoing fractional flow reserve (FFR) assessment from 2002 to 2009,we identified 167 patients in whom FFR was measured in at least one 70%–89% stenotic lesion. These patients were subdivided into an FFR-defer group (n = 49) if PCI was deferred (FFR > 0.80),and an FFR-perform group (n = 118) if PCI was performed (FFR ≤ 0.80). Comparatively,an additional 1176 patients undergoing PCI in at least one lesion with 70%–89% stenosis but without measurement of FFR served as a control (angiography- guided) group. Clinical outcomes were compared during a median follow-up of 49.0 months. The 5-year Kaplan-Meier estimated revascularization rates were 16% in the FFR-defer group and 33% in the FFR-perform group (P = 0.046). The incidence of major adverse cardiac events were comparable in these two groups (HR = 0.82,95% CI: 0.37–1.82,P = 0.63). The number of stents placed was significantly lower in the FFR-guided group (0.9 ± 0.8 vs. 1.4 ± 0.8,P < 0.001). Conclusions Functional revascularization for lesions with visually severe stenosis is clinically safe and associated with fewer stents use. This study suggests that extending the use of FFR to more severe coronary lesions may be reasonable.

Clinical applications of fractional flow reserve in bifurcation lesions

Pereutaneous coronary intervention （PCI） for coronary bifurcation lesions has been associated with lower procedural success rates and worse clinical outcomes compared with PCI for simple coronary lesions. Angiographic evaluation alone is sometimes inaccurate and does not reflect the fimctional significance of bifurcation lesions. The fractional flow reserve （FFR） is an easily obtainable, reliable, and reproducible physiologic parameter. This parameter is epicardial lesion specific and reflects both degree of stenosis and the myocardial territory supplied by the specific artery. Recent studies have shown that FFR-guided provisional side branch intervention strategy for bifurcation lesions is feasible and effective and can reduce unnecessary complex interventions and related complications. However, an adequate understanding of coronary physiology and the pitfalls of FFR is essential to properly use FFR for PCI of complex bifurcation lesions.

A Fast-Fractional Flow Reserve Simulation Method in A Patient with Coronary Stenosis Based on Resistance Boundary Conditions

Fractional flow reserve(FFR)is the gold standard to identify individual stenosis causing myocardial ischemia in catheter laboratory.The purpose of this study is to present a fast simulation method to estimate FFR value of a coronary artery,which can evaluate the performance of vascular stenosis,based on resistance boundary conditions.A patient-specific 3-dimensional(3D)model of the left coronary system with intermediate diameter stenosis was reconstructed based on the CTA images.The resistance boundary conditions used to simulate the coronary microcirculation were computed based on anatomical reconstruction of coronary 3D model.This study was performed by coupling the 3D coronary tree model with the lumped parameter model(0D model).The flow rate and pressure of coronary tree were calculated in twenty minutes.In addition,the effect of inlet pressure and myocardial mass on FFRss values has been investigated.The results showed that the effect of myocardial mass was greater than the effect of inlet pressure on FFRss.This FFRss simulation method can quickly and accurately assess the influence of coronary stenosis in aid clinical diagnosis.

慢性冠脉综合征患者血尿酸及钙化积分对CT-FFR的影响

目的:探讨血尿酸及钙化积分对深度学习算法下冠脉综合征(CCS)患者血流储备分数(CT-FFR)的影响。方法:回顾性分析150例冠状动脉(冠脉)CTA(CCTA)示靶血管狭窄的慢性CCS患者,采用深度学习法计算其CT-FFR,取3支靶血管中最低值作为该患者CT-FFR,按CT-FFR>0.8及CT-FFR≤0.8分为正常组77例、异常组73例,比较2组血尿酸值及总钙化积分;采用SPSS26.0统计软件对CT-FFR、血尿酸、钙化积分行Pearson分析;使用logistic回归分析且通过ROC曲线评估其诊断效能。结果:2组在钙化积分上差异有统计学意义(Z=-5.958,P<0.05),而血尿酸差异无统计学意义(t=-0.448,P>0.05);Pearson相关分析得出,钙化积分与CT-FFR呈显著负相关(r=-0.556,P<0.05);ROC曲线的AUC为0.782,且达到病变程度(CT-FFR≤0.8)的钙化积分阈值为313.05分,约登指数为0.464,其诊断准确率为78.2%,敏感度为68.5%,特异度为77.9%。结论:冠脉钙化积分可能影响CTFFR,可预测功能性缺血的发生,即钙化积分越高,血管功能越差,CT-FFR越低,缺血越严重。CCS患者血尿酸是否与CT-FFR存在相关性有待进一步研究。

探讨芪参益气滴丸对FFR为临界值的冠心病患者心血管临床事件的影响

目的分析芪参益气滴丸对血流储备分数(FFR)为临界值的冠心病患者心血管临床事件的影响。方法60例FFR为临界值的冠心病患者,将其以案例排序数字的奇偶性作为分组标准,排序数字为奇数的30例患者纳入对照组,排序数字为偶数的30例患者纳入试验组。对照组实施常规药物治疗,试验组在对照组的基础上联合芪参益气滴丸治疗。比较两组患者治疗前后心功能指标、西雅图心绞痛量表(SAQ)积分、中医证候积分和不良事件发生情况。结果治疗后,两组患者的左心室收缩末期内径(LVESd)、左心室舒张末期内径(LVEDd)均小于本组治疗前,且试验组患者的LVESd(32.25±3.27)mm、LVEDd(40.31±4.22)mm小于对照组的(36.81±4.69)、(46.67±5.47)mm,有统计学意义(P<0.05);两组患者的左心室射血分数(LVEF)高于本组治疗前,且试验组患者高于对照组,但差异较小,无统计学意义(P>0.05)。治疗后,两组患者的SAQ积分均较治疗前显著提高,且试验组患者SAQ积分(86.26±10.33)分高于对照组的(76.53±8.75)分,有统计学意义(P<0.05)。治疗后,两组患者的胸痛胸闷、心悸气短、头晕乏力、呼吸困难积分均较治疗前显著降低,且试验组患者胸痛胸闷、心悸气短、头晕乏力、呼吸困难积分分别为(1.02±0.25)、(0.96±0.22)、(0.95±0.24)、(0.92±0.17)分,均低于对照组的(1.34±0.29)、(1.17±0.30)、(1.19±0.31)、(1.05±0.23)分,有统计学意义(P<0.05)。试验组患者的心血管临床事件发生率3.33%低于对照组的20.00%,有统计学意义(P<0.05)。试验组患者的肝肾功能异常发生率低于对照组,但差异较小,无统计学意义(P>0.05)。结论芪参益气滴丸对FFR为临界值的冠心病患者治疗效果较好,可改善心功能指标,缓解心绞痛,有助于降低心血管临床事件的发生风险,是一种安全有效的治疗方式,值得推广应用。

基于CAD-RADS的高危斑块特征联合CT-FFR对冠状动脉临界病变预后的预测价值

目的:研究基于冠状动脉疾病报告和数据系统(coronary artery disease-reporting and data system,CAD-RADS)的高危斑块特征联合CT血流储备分数(fractional flow reserve derived from CT,CT-FFR)对冠状动脉病临界病变患者预后的临床应用价值。方法:在CAD-RADS结构式报告基础上,前瞻性研究冠状动脉CT血管造影(coronary artery CT angiography,CCTA)影像资料和临床资料,共301例临界病变患者纳入研究,影像观察指标包括CAD-RADS≥3、钙化积分≥100、斑块易损性特征、高危斑块、长病变、CT-FFR≤0.8,观察指标的组合包括CAD-RADS≥3 V、CAD-RADS≥3 V且CT-FFR≤0.8。研究终点为预后不良,包括主要不良心血管事件(major adverse cardiovascular events,MACE)及计划外有创冠状动脉造影(invasive coronary angiography,ICA)、血运重建手术,研究样本分为预后良好组和预后不良组。通过统计不同组间数据的差异,评价CAD-RADS高危斑块联合CT-FFR对临界病变患者预后的临床价值。结果:年龄、钙化积分、CAD-RADS类别、斑块易损性特征、高危斑块、长病变、CT-FFR在预后良好组和预后不良组间的差异有统计学意义(P<0.05);CAD-RADS类别、高危斑块、CT-FFR是冠状动脉临界病变预后的独立预测因子(P<0.05);CT-FFR≤0.8在CAD-RADS≥3组、钙化积分≥100组、不同斑块易损性特征组、高危斑块组、长病变组中发生率差异均有统计学意义(均P<0.05);观察指标组合(CAD-RADS≥3 V且CT-FFR≤0.8)预测预后不良的特异性、准确性和阳性预测值分别为97.2%、85.7%、88.7%,AUC为0.795(95%CI:0.731~0.858)。结论:基于CAD-RADS的高危斑块特征联合CT-FFR能有效预测MACE及计划外ICA、血运重建手术,指导临床针对性干预与治疗。

Fractional Flow Reserve Measurement by Coronary Computed Tomography Angiography:A Review with Future Directions

Invasive fractional fl ow reserve(FFR)measurement is currently the gold standard for coronary intervention.FFR measurement by coronary computed tomography angiography(FFRCT)is a novel and promising imaging technology that permits noninvasive assessment of physiologically signifi cant coronary lesions.FFRCT is capable of combining the anatomic information provided by coronary computed tomography angiography with computational fl uid dynamics to compute FFR.To date,several studies have reported the diagnostic performance of FFRCT compared with invasive FFR measurement as the reference standard.Further studies are now being implemented to determine the clinical feasibility and economic implications of FFRCT techniques.This article provides an overview and discusses the available evidence as well as potential future directions of FFRCT.

Fractional Flow Reserve-guided Percutaneous Coronary Intervention:Standing the Test of Time

Percutaneous coronary intervention(PCI)improves symptoms and prognosis in ischemia-inducing,functionally signifi cant,coronary lesions.Use of fractional flow reserve allows physicians to investigate the ischemia-inducing potential of a specifi c lesion and can be used to guide coronary revascularization,especially in multivessel coronary artery disease.Fractional flow reserve-guided PCI has been extensively investigated.Results show that deferral of stenting in non-signifi cant lesions is safe,whereas deferral of stenting in functionally signifi cant lesions worsens outcome.FFR-guided PCI improves outcome in multivessel disease over angiography-guided PCI.Until recently,there was little known about the long-term outcome of FFR-guided revascularization and its validity in acute coronary syndromes.This review aims to address the new evidence regarding long-term appropriateness of FFR-guided PCI,the need for hyperemia to evaluate functional severity,and the use of FFR in acute coronary syndromes.

Comparative efficacy and safety of adenosine and regadenoson for assessment of fractional flow reserve:A systematic review and meta-analysis

BACKGROUND Adenosine is a coronary hyperemic agent used to measure invasive fractional flow reserve(FFR)of intermediate severity coronary stenosis.AIM To compare FFR assessment using adenosine with an alternate hyperemic agent,regadenoson.METHODS PubMed,Google Scholar,CINAHL and Cochrane databases were queried for studies comparing adenosine and regadenoson for assessment of FFR.Data on FFR,correlation coefficient and adverse events from the selected studies were extracted and analyzed by means of random effects model.Two tailed P-value less than 0.05 was considered significant.Heterogeneity was assessed using I2 test.RESULTS Five studies with 248 patients were included in the final analysis.All included patients and coronary lesions underwent FFR assessment using both adenosine and regadenoson.There was no significant mean difference between FFR measurement by the two agents[odds ratio(OR)=-0.00;95%confidence interval(CI):(-0.02)-0.01,P=0.88].The cumulative correlation coefficient was 0.98(0.96-0.99,P<0.01).Three of five studies reported time to FFR with cumulative results favoring regadenoson(mean difference 34.31 s;25.14-43.48 s,P<0.01).Risk of adverse events was higher with adenosine compared to regadenoson(OR=2.39;95%CI:1.22-4.67,P=0.01),which most commonly included bradycardia and hypotension.Vast majority of the adverse events associated with both agents were transient.CONCLUSION The performance of regadenoson in inducing maximal hyperemia was comparable to that of adenosine.There was excellent correlation between the FFR measurements by both the agents.The use of adenosine,was however associated with higher risk of adverse events and longer time to FFR compared to regadenoson.

Comparison of Fractional Flow Reserve-Guided Revascularization Strategies in Isolated Proximal Left Anterior Descending Coronary Artery Disease

The data about FFR-guided revascularization in isolated proximal LAD disease are limited and studies comparing long-term outcomes of FFR-guided PCI versus FFR-guided CABG in single-vessel proximal LAD disease are lacking. We aimed to assess the 4-year long-term safety and effectiveness of fractional flow reserve (FFR)-guided percutaneous coronary intervention (PCI) and FFR-guided coronary artery bypass graft surgery (CABG) for the treatment of proximal left anterior descending (LAD) lesions. The study included 129 patients with functionally significant (FFR ≤ 0.80) isolated proximal LAD stenosis (PCI, 88 patients vs. CABG, 41). Clinical endpoints were assessed by Kaplan-Meier method and compared by the log-rank test. At a mean follow-up time of 47 ± 12 months, a higher incidence of myocardial infarction in the PCI group (PCI: 32% vs. CABG: 15%;p = 0.003) and a higher incidence of stroke in the CABG group (CABG: 3 (7%) vs. PCI 0 (0%);p = 0.031) were observed. However, there were no significant differences in the primary composite endpoint, death and target vessel revascularization between PCI and CABG groups. The PCI and CABG in isolated proximal LAD lesions yielded similar long-term outcomes regarding the primary composite clinical endpoints. However, stroke was more frequent in the CABG group than in the PCI group.

Modes of failure with fractional flow reserve guidewires:Insights from the manufacturer and user facility device experience database

BACKGROUND Fractional flow reserve(FFR)measurement is commonly used in the cardiac catheterization laboratory to assess the functional significance of coronary arterial plaques.Robust real-world data on complications and modes of failure of FFR guidewires are limited.AIM To characterize these outcomes by analyzing the post-marketing surveillance data from the United States Food and Drug Administration Manufacturer and User Facility Device Experience(MAUDE)database for commonly used FFR guidewires.METHODS The MAUDE database was queried from January 2010 through April 2020 for 3 FFR guidewires[PressureWireTM X(Abbott),CometTM(Boston Scientific),and VerrataTM(Philips)]by searching for the following events:“Injury”,“malfunction”,“death”,and“other”.This yielded 544 reports.After excluding incomplete reports,486 reports were analyzed.RESULTS Guidewire tip fracture was the most commonly reported mode of failure,in 174(35.8%)cases followed by guidewire kinking(n=152,31.3%),communication failure(n=141,29.0%),and shaft fracture(n=67,13.8%).In total,133(27.4%)device failures resulted in patient adverse events.The most common adverse event was retained guidewire tip,in 71(53.4%)cases,followed by freshly deployed stent dislodgment(n=26,19.6%)and coronary artery dissection(n=23,17.3%).Seven deaths were reported.CONCLUSION FFR guidewire failures can occur because of various mechanisms and cause patient adverse events.The MAUDE database serves as an important platform for improved collaboration among clinicians,device manufacturers,and regulators to improve device performance and optimize patient outcomes.Our analysis provides mechanistic insights of FFR guidewire failure and associated adverse events but cannot verify causality or provide a comparison among different guidewires.

Usefulness of Fractional Flow Reserve during Routine Clinical Procedures in All-Comer Coronary Artery Disease Patients

Background: Fractional flow reserve (FFR)-guided interventions, though proved to be safe, continue to be a much-underutilized modality in determining treatment strategy, and data is lacking in Indian population. Objective: We aimed to determine the use of FFR-guided PCI and assess the overall impact on treatment decisions and clinical outcomes in patients with acute coronary syndrome (ACS) or chronic coronary syndromes (CCS). Methods: In this single-center retrospective and prospective observational study, FFR had been performed for the evaluation of treatment reclassification and clinical outcomes, as per physician’s clinical practice. Results: Data was obtained for 250 subjects (mean age 60.45 ± 9.6 years) with 324 lesions. The treatment plan based on angiography alone changed in 28% of lesions post-hyperemic FFR. The initial treatment plan based on angiography vs. the final treatment plan post-FFR (>0.80) was medical management 56.5% vs. 66.0%;CABG 11.1% vs. 7.7%;and PCI 32.4% vs. 26.2%. In subjects initially assigned to medical management, 14% had changed to PCI, and for subjects initially assigned to PCI, 44% had changed to medical therapy. Receiver operating characteristics (ROC) curve analysis revealed a good correlation between a resting FFR value of <0.87 and hyperemic FFR value of <0.80. The rate of 2-year major adverse cardiovascular events (MACE) was 0.9%. Conclusion: This study supports the use of FFR in determining treatment strategy in ACS or CCS patients with low MACE. Resting FFR value of <0.87 may be an alternative to intracoronary nitroglycerine/adenosine/Nikorandil-induced FFR in predicting positive FFR particularly in hemodynamically unstable patients, and who are intolerant to hyperemic drugs.