FFR-Guided PCI Optimization Directed by High-Definition IVUS Versus Standard of Care: The FFR REACT Trial

BackgroundPost–percutaneous coronary intervention (PCI) fractional flow reserve (FFR) <0.90 is common and has been related to impaired patient outcome.ObjectivesThe authors sought to evaluate if PCI optimization directed by intravascular ultrasound (IVUS) in patients with post-PCI FFR <0.90 could improve 1-year target vessel failure (TVF) rates.MethodsIn this single-center, randomized, double-blind trial, patients with a post-PCI FFR <0.90 at the time of angiographically successful PCI were randomized to IVUS-guided optimization or the standard of care (control arm). The primary endpoint was TVF (a composite of cardiac death, spontaneous target vessel myocardial infarction, and clinically driven target vessel revascularization) at 1 year.ResultsA total of 291 patients with post-PCI FFR <0.90 were randomized (IVUS-guided optimization arm: n = 145/152 vessels, control arm: n = 146/157 vessels). The mean post-PCI FFR was 0.84 ± 0.05. A total of 104 (68.4%) vessels in the IVUS-guided optimization arm underwent additional optimization including additional stenting (34.9%) or postdilatation only (33.6%), resulting in a mean increase in post-PCI FFR in these vessels from 0.82 ± 0.06 to 0.85 ± 0.05 (P < 0.001) and a post-PCI FFR ≥0.90 in 20% of the vessels. The 1-year TVF rate was comparable between the 2 study arms (IVUS-guided optimization arm: 4.2%, control arm: 4.8%; P = 0.79). There was a trend toward a lower incidence of clinically driven target vessel revascularization in the IVUS-guided optimization arm (0.7% vs. 4.2%, P = 0.06).ConclusionsIVUS-guided post-PCI FFR optimization significantly improved post-PCI FFR. Because of lower-than-expected event rates, post-PCI FFR optimization did not significantly lower TVF at the 1-year follow-up.     

Clinical and Prognostic Impact From Objective Analysis of Post-Angioplasty Fractional Flow Reserve Pullback

ObjectivesThis study sought to evaluate clinical implications of the residual fractional flow reserve (FFR) gradient after angiographically successful percutaneous coronary intervention (PCI).BackgroundRecent studies have demonstrated FFR measured after PCI is associated with clinical outcome after PCI. Although post-PCI FFR pull back tracings provide clinically relevant information on the residual FFR gradient, there are no objective criteria for assessing post-PCI FFR pull back tracings.MethodsA total of 492 patients who underwent angiographically successful PCI and post-PCI FFR measurement with pull back tracings were analyzed. The presence of the major residual FFR gradient after PCI was assessed by both conventional visual interpretation of the pull back tracings and objective analysis using the instantaneous FFR gradient per unit time (dFFR(t)/dt) with a cutoff value of dFFR(t)/dt ≥0.035. Classification agreement between 2 independent operators for the presence of the major residual FFR gradient was compared before and after providing dFFR(t)/dt results. Target vessel failure (TVF), a composite of cardiac death, target vessel myocardial infarction, or clinically driven target vessel revascularization at 2 years, was compared according to the presence of the major residual FFR gradient.ResultsAmong the study population, 33.9% had the major residual FFR gradient defined by dFFR(t)/dt. The classification agreement between operators’ assessments for the major residual FFR gradient increased with dFFR(t)/dt results compared with conventional visual assessment (Cohen’s kappa = 0.633 to 0.819; P < 0.001; intraclass correlation coefficient: 0.776 to 0.901; P < 0.001). Patients with major residual FFR gradient were associated with a higher risk of TVF at 2 years than those without major residual FFR gradient (9.0% vs 2.2%; P < 0.001). Inclusion of the major residual FFR gradient to a clinical prediction model significantly increased discrimination and reclassification ability (C-index = 0.539 vs 0.771; P = 0.006; net reclassification improvement = 0.668; P = 0.007; integrated discrimination improvement = 0.033; P = 0.017) for TVF at 2 years. The presence of the major residual FFR gradient was independently associated with TVF at 2 years, regardless of post-PCI FFR or percent FFR increase (adjusted hazard ratio: 3.930; 95% confidence interval: 1.353-11.420; P = 0.012).ConclusionsObjective analysis of post-PCI FFR pull back tracings using dFFR(t)/dt improved classification agreement on the presence of the major residual FFR gradient among operators. Presence of the major residual FFR gradient defined by dFFR(t)/dt after angiographically successful PCI was independently associated with an increased risk of TVF at 2 years. (Automated Algorithm Detecting Physiologic Major Stenosis and Its Relationship with Post-PCI Clinical Outcomes [Algorithm-PCI]; NCT04304677; Influence of FFR on the Clinical Outcome After Percutaneous Coronary Intervention [COE-PERSPECTIVE]; NCT01873560)     

Prognostic Implications of Post-Intervention Resting Pd/Pa and Fractional Flow Reserve in Patients With Stent Implantation

ObjectivesThis study sought to investigate the prognostic implications of post–percutaneous coronary intervention (PCI) nonhyperemic pressure ratios compared with that of post-PCI fractional flow reserve (FFR).BackgroundFFR measured after PCI has been shown to possess prognostic implications. However, the prognostic value of post-PCI nonhyperemic pressure ratios has not yet been clarified.MethodsA total of 588 patients who underwent PCI with available both post-PCI FFR and resting distal coronary pressure-to-aortic pressure ratio (Pd/Pa) were analyzed. Post-PCI FFR and Pd/Pa were measured after successful angiographic stent implantation. The primary outcome was target vessel failure (TVF) up to 2 years, defined as a composite of cardiac death, target vessel–related myocardial infarction, and clinically driven target vessel revascularization. Prognosis of patients according to post-PCI Pd/Pa was compared with that of post-PCI FFR.ResultsDespite angiographically successful PCI, 18.5% had post-PCI FFR ≤0.80 and 36.9% showed post-PCI Pd/Pa ≤0.92. In post-PCI Pd/Pa >0.92 group, 93.8% of patients showed post-PCI FFR >0.80. Conversely, 60.4% of patients showed post-PCI FFR >0.80 in post-PCI Pd/Pa ≤0.92 group. Although there was significant difference in TVF according to post-PCI FFR (≤0.80 vs. >0.80: 10.3% vs. 2.5%; p < 0.001) and Pd/Pa (≤0.92 vs. >0.92: 6.2% vs. 2.5%; p = 0.029), the reclassification ability of model for TVF was increased only with post-PCI FFR (net reclassification index 0.627; p = 0.003; integrated discrimination index 0.019; p = 0.015), but not with post-PCI Pd/Pa, compared with model including clinical factors. Compared with patients with post-PCI Pd/Pa >0.92, patients with post-PCI Pd/Pa ≤0.92 and FFR ≤0.80 had significantly higher risk of TVF (10.4% vs. 2.5%; adjusted hazard ratio: 4.204; 95% confidence interval: 1.521 to 11.618; p = 0.006); however, those with post-PCI Pd/Pa ≤0.92 but FFR >0.80 showed similar risk of TVF (3.5% vs. 2.5%; adjusted hazard ratio: 1.327; 95% confidence interval: 0.398 to 4.428; p = 0.645).ConclusionsOver one-half of the patients with abnormal post-PCI Pd/Pa ≤0.92 showed post-PCI FFR >0.80. Compared with post-PCI FFR, post-PCI Pd/Pa showed limited reclassification ability for the occurrence of TVF. Among patients with abnormal post-PCI Pd/Pa, only patients with positive post-PCI FFR showed significantly higher risk of TVF than did those with post-PCI Pd/Pa >0.92. (Prognostic Perspective of Invasive Hyperemic and Non-Hyperemic Physiologic Indices Measured After Percutaneous Coronary Intervention [PERSPECTIVEPCI]; NCT04265443)     

Prognostic Implications of Relative Increase and Final Fractional Flow Reserve in Patients With Stent Implantation

Objectives

The study sought to investigate the prognostic implications of relative increase of fractional flow reserve (FFR) with PCI in combination with post–percutaneous coronary intervention (PCI) FFR.

血流储备分数指导经皮冠状动脉介入治疗术中非罪犯中度狭窄血管治疗策略的研究

目的：通过测量血流储备分数（FFR）,决定是否对不稳定型心绞痛多支血管病变患者经皮冠状动脉介入治疗（PCI）术中非罪犯中度狭窄血管行介入治疗,并观察临床转归。方法本研究入选不稳定型心绞痛多支血管病变患者,首先对已明确的罪犯血管行PCI治疗后,针对非罪犯中度狭窄血管按照单双号分为对照组（非支架组）和观察组（FFR指导下行PCI组）。其中,观察组FFR＜0.8的患者对中度狭窄血管行PCI治疗,术后再次行FFR检测,确保FFR≥0.95。观察终点事件为全因死亡、非致死性心肌梗死、再次血运重建发生率以及心绞痛临床表现。结果共纳入71例患者,对照组35例;观察组36例,其中FFR≥0.8的患者23例,FFR＜0.8的患者13例。两组患者无主要终点事件和再次血运重建生存率分别比较,差异均有统计学意义（P＜0.05）;无全因死亡与非致死性心肌梗死生存率分别比较,差异均无统计学意义。针对靶血管不良事件的统计学分析显示,两组再次血运重建（观察组5.6%,对照组31.4%）及非致死性心肌梗死（观察组5.6%,对照组28.6%）发生率分别比较,差异均有统计学意义（P＜0.05）。结论不稳定型心绞痛患者中,使用压力导丝测出的FFR值来决定是否对非罪犯中度病变进行血运重建是安全的。FFR结合冠状动脉造影指导PCI治疗较单纯冠状动脉造影指导PCI的不良事件发生率显著减少,尤其在再次血运重建方面,并且心绞痛临床表现显著缓解。     

Evaluation of troponin T criteria for periprocedural myocardial infarction in patients with acute coronary syndromes

In patients with acute coronary syndromes undergoing percutaneous coronary intervention (PCI), the diagnosis of periprocedural myocardial infarction is often problematic when the pre-PCI levels of cardiac troponin T (TnT) are elevated. Thus, we examined different TnT criteria for periprocedural myocardial infarction when the pre-PCI TnT levels were elevated and also the associations between the post-PCI cardiac marker levels and outcomes. We established the relation between the post-PCI creatine kinase-MB (CKMB) and TnT levels in 582 patients (315 with acute coronary syndromes and 272 with stable coronary heart disease). A post-PCI increase in the CKMB levels to 14.7 μg/L (3 × the upper reference limit [URL] in men) corresponded to a TnT of 0.23 μg/L. In the 85 patients with acute coronary syndromes and normal CKMB, but elevated post peak TnT levels before PCI (performed at a median of 5 days, interquartile range 3 to 7), the post-PCI cardiac marker increases were as follows: 21 (24.7%) with a ≥ 20% increase in TnT, 10 (11.8%) with an CKMB level >3 × URL, and 12 (14%) with an absolute TnT increase of >0.09 μg/L (p <0.005 for both). In the patients with stable coronary heart disease and post-PCI cardiac markers > 3× URL compared to those without markers elevations, the rate of freedom from death or nonfatal myocardial infarction was 88% for those with TnT elevations versus 99% (p <0.001, log-rank) and 84% for those with CKMB elevations versus 98% (p <0.001, log-rank). Of the patients with acute coronary syndromes, the post-PCI marker levels did not influence the outcomes. In conclusion, in patients with acute coronary syndromes and elevated TnT levels undergoing PCI several days later, ≥20% increases in TnT were more common than absolute increments in the TnT or CKMB levels of >3× URL. Also, periprocedural cardiac marker elevations in patients with acute coronary syndromes did not have prognostic significance.     

1-Year Outcomes of Blinded Physiological Assessment of Residual Ischemia After Successful PCI: DEFINE PCI Trial

ObjectivesThe aim of this study was to identify the post–percutaneous coronary intervention (PCI) target value of instantaneous wave-free ratio (iFR) that would best discriminate clinical events at 1 year in the DEFINE PCI (Physiologic Assessment of Coronary Stenosis Following PCI) study.BackgroundThe impact of residual ischemia detected by iFR post-PCI on clinical and symptom-related outcomes is unknown.MethodsBlinded iFR pull back was performed after successful stent implantation in 500 patients. The primary endpoint was the rate of residual ischemia, defined as iFR ≤0.89, after operator-assessed angiographically successful PCI. Secondary endpoints included clinical events at 1 year and change in Seattle Angina Questionnaire angina frequency (SAQ-AF) score during follow-up.ResultsAs reported, 24.0% of patients had residual ischemia (iFR ≤0.89) after successful PCI, with 81.6% of cases attributable to angiographically inapparent focal lesions. Post-PCI iFR ≥0.95 (present in 182 cases [39%]) was associated with a significant reduction in the composite of cardiac death, spontaneous myocardial infarction, or clinically driven target vessel revascularization compared with post-PCI iFR <0.95 (1.8% vs 5.7%; P = 0.04). Baseline SAQ-AF score was 73.3 ± 22.8. For highly symptomatic patients (baseline SAQ-AF score ≤60), SAQ-AF score increased by ≥10 points more frequently in patients with versus without post-PCI iFR ≥0.95 (100.0% vs 88.5%; P = 0.01).ConclusionsIn DEFINE PCI, despite angiographically successful PCI, highly symptomatic patients at baseline without residual ischemia by post-PCI iFR had greater reductions in anginal symptoms at 1 year compared with patients with residual ischemia. Achieving post-PCI iFR ≥0.95 was also associated with improved 1-year event-free survival. (Physiologic Assessment of Coronary Stenosis Following PCI [DEFINE PCI]; NCT03084367)     

Blinded Physiological Assessment of Residual Ischemia After Successful Angiographic Percutaneous Coronary Intervention: The DEFINE PCI Study

ObjectivesThis study sought to evaluate the incidence and causes of an abnormal instantaneous wave-free ratio (iFR) after angiographically successful percutaneous coronary intervention (PCI).BackgroundImpaired coronary physiology as assessed by fractional flow reserve is present in some patients after PCI and is prognostically relevant.MethodsDEFINE PCI (Physiologic Assessment of Coronary Stenosis Following PCI) was a multicenter, prospective, observational study in which a blinded iFR pull back was performed after angiographically successful PCI in 562 vessels in 500 patients. Inclusion criteria were angina with either multivessel or multilesion coronary artery disease with an abnormal baseline iFR. The primary endpoint of the study was the rate of residual ischemia after operator-assessed angiographically successful PCI, defined as an iFR <0.90. The causes of impaired iFR were categorized as stent related, untreated proximal or distal focal stenosis, or diffuse atherosclerosis.ResultsAn average of 1.1 vessels per patient had abnormal baseline iFRs, with a mean value of 0.69 ± 0.22, which improved to 0.93 ± 0.07 post-PCI. Residual ischemia after angiographically successful PCI was present in 112 patients (24.0%), with a mean iFR in that population of 0.84 ± 0.06 (range 0.60 to 0.89). Among patients with impaired post-PCI iFRs, 81.6% had untreated focal stenoses that were angiographically inapparent, and 18.4% had diffuse disease. Among the focal lesions, 38.4% were located within the stent segment, while 31.5% were proximal and 30.1% were distal to the stent. Post-PCI vessel angiographic diameter stenosis was not a predictor of impaired post-procedural iFR.ConclusionsBlinded post-PCI physiological assessment detected residual ischemia in nearly 1 in 4 patients after coronary stenting despite an operator-determined angiographically successful result. Most cases of residual ischemia were due to inapparent focal lesions potentially amenable to treatment with additional PCI. (Physiologic Assessment of Coronary Stenosis Following PCI [DEFINE PCI]; NCT03084367)     

Coronary pressure measurement based decision making for percutaneous coronary intervention

The fractional flow reserve (FFR) is a simple, reliable, and reproducible physiologic index of lesion severity. In patients with intermediate stenosis, FFR≥0.75 can be used to safely defer percutaneous coronary intervention (PCI), and patients with FFR≥0.75 have a very low cardiac event rate. Coronary pressure measurement can determine which lesion should be treated with PCI in patients with tandem lesions, and PCI on the basis of FFR has been demonstrated to result in an acceptably low repeat PCI rate. FFR can identify patients with equivocal left main coronary artery disease who benefit from coronary bypass surgery. Coronary pressure measurement distinguishes patients with an abrupt pressure drop pattern from those with a gradual pressure drop pattern, and the former group of patients benefit from PCI. Coronary pressure measurement is clinically useful in evaluating sufficient recruitable coronary collateral blood flow for prevention of ischemia, which affects future cardiac events. FFR is useful for the prediction of restenosis after PCI. As an end-point of PCI, FFR ≥0.95 and ≥0.90 would be appropriate for coronary stenting and coronary angioplasty, respectively. In summary, if you encounter a coronary stenosis in doubt you should measure pressure rather than dilate it.     

Long-term clinical outcomes after deferral of percutaneous coronary intervention of intermediate coronary stenoses based on coronary pressure-derived fractional flow reserve

Coronary pressure-derived fractional flow reserve (FFR) has been used to evaluate functional severity of coronary artery stenoses. The cut-off point of 0.75 was considered to be the indication for percutaneous coronary intervention (PCI). In this study, we examined the prognosis of patients in whom PCI was deferred because the lesion was not significant by FFR (≥0.75). We measured FFR of 44 patients (50 lesions with angiographically intermediate stenoses by pressure wire between 2002 and 2009. Out of 44 patients (50 lesions), functionally non-significant stenoses with FFR≥0.75 were 29 patients (33 lesions) and PCI was deferred. In the remaining 15 patients (17 lesions), FFR was <0.75 and PCI was performed. Patients were followed up for an average period of 53 months with endpoints of major adverse cardiac events (MACE; cardiac death, acute coronary syndrome, PCI, and coronary artery bypass grafting). The rate of MACE was 2/29 (6.9%) in patients with FFR≥0.75 and 2/15 (13.3%) in those with FFR<0.75, and it was not statistically different between the two groups. Since long-term clinical outcomes after deferral of PCI of intermediate coronary stenoses based on FFR were excellent (annual event rate 1.6%/year), FFR is a useful index to judge the indication of PCI and risk-stratify patients for MACE.     

Risk factors of acute myocardial infarction following primary percutaneous coronary intervention among elderly patients

Background and Objective Large randomized controlled trials have demonstrated that percutaneous coronary intervention （PCI） with the routine use of drug-eluting stents is safe and effective, however, the patients older than 75 years undergoing PCI are at increased risk for major adverse cardiac events, so that the patients are usually excluded from this trial. The aim of the present study was to assess the early clinical outcome and risk factors in old patients with acute ST elevation myocardial infarction （STEMI） following primary PCI. Methods We analyzed the outcome after stenting in 136 patients older than 60 years in our coronary care unit with acute STEMI, and the patients were further classified in 2 age groups： patients≥75 years and 〈75 years. Results Though the older group had a higher prevalence of adverse baseline characteristics and lower final TIMI flow than those of the younger, the procedural success had no difference between two groups. The main adverse clinical events （MACE） for the old group was a little higher comparing with the younger in 12-month following up. Conclusions Our study suggest that drug-eluting stent implantation in elderly patients with acute ST elevation myocardial infarction has high initial procedural success rates despite having more severe baseline risk characteristics, and to shorten the time form symptom onset to PCI and improve final TIMI flow strategy may decrease MACE among old patients following PCI（J Geriatr Cardio12009; 6：67-70）.     

Pulse transmission coefficient: a nonhyperemic index for physiologic assessment of procedural success following percutaneous coronary interventions.

Intracoronary pressure measurements and the determination of fractional flow reserve (FFR) after percutaneous coronary intervention (PCI) predict adverse events. Coronary lesions may impair the transmission of pressure waves across a stenosis, potentially acting as a high-frequency filter. The pulse transmission coefficient (PTC) is a nonhyperemic parameter that calculates the transmission of high-frequency components of the pressure signal through a stenosis. It was shown recently that PTC is highly correlated with FFR. This study was designed to examine the change of PTC as compared to FFR following PCI. Pressure signals were obtained by pressure guidewire in 27 lesions pre- and post-PCI and were analyzed with an algorithm that identifies the high-frequency component in the pressure signal. The PTC was calculated at baseline as the ratio between distal and proximal high-frequency components of the pressure waveform across the lesion. FFR measurements were assessed with intracoronary adenosine. There was a significant increase in PTC following PCI (0.15 +/- 0.17 at baseline vs. 0.84 +/- 0.11 post-PCI; P < 0.001). Comparable changes were observed for FFR (0.58 +/- 0.12 at baseline vs. 0.91 +/- 0.05 post-PCI; P < 0.001). PTC is a nonhyperemic parameter for physiologic assessment of coronary artery stenoses. Similar to FFR, PTC is significantly increased following PCI. Thus, it may serve as an adjunct index for the functional assessment of procedural success following PCI.     

Relation of fractional flow reserve after drug-eluting stent implantation to one-year outcomes

Patients still present with drug-eluting stent (DES) failure despite an angiographically successful implantation. The aim of the present study was to investigate the relation between the fractional flow reserve (FFR) measured after DES implantation and the clinical outcomes at 1 year. A total of 80 patients (mean age 62 years, 74% men, 99 DESs) underwent coronary pressure measurement at maximum hyperemia after successful DES implantation. The composite of major adverse cardiac events (MACE), including death, myocardial infarction, and ischemia-driven target vessel revascularization was evaluated at 1 year. The patients were divided into 2 groups (low-FFR group, FFR ≤0.90 and high-FFR group, FFR >0.90) according to the median FFR. The mean poststent percent diameter stenosis was 11 ± 5% in the low-FFR group and 12 ± 3% in the high-FFR group (p = 0.31). Left anterior descending coronary artery lesions were more frequent in the low-FFR group than in the high-FFR group (82% vs 55%, p = 0.02). The mean stent length was greater in the low-FFR group than in the high-FFR group (38 ± 18 vs 28 ± 13 mm, p = 0.01). Six cases (7.5%) of MACE occurred during the 1-year follow-up. The rate of MACE was 12.5% in the low-FFR group and 2.5% in the high-FFR group (p <0.01). Receiver operating characteristic curves revealed 0.90 as the best cutoff of FFR after DES implantation for the prediction of 1-year MACE. In conclusion, a poststent FFR of ≤0.90 correlated with a greater adverse event rate at 1 year.     

Incremental Prognostic Value of Post-Intervention Pd/Pa in Patients Undergoing Ischemia-Driven Percutaneous Coronary Intervention

ObjectivesThis study sought to evaluate the prognostic value of post–percutaneous coronary intervention (PCI) distal coronary pressure to aortic pressure ratio (Pd/Pa) in predicting long-term clinical outcomes and to determine whether Pd/Pa combined with fractional flow reserve (FFR) post-intervention provides additional prognostic information superior to either marker alone.BackgroundPost-PCI FFR has been shown to be a predictor of long-term outcomes in numerous studies. The role of post-PCI resting Pd/Pa has not been previously studied in this setting.MethodsConsecutive patients undergoing PCI who had pre- and post-PCI Pd/Pa and FFR were followed for major adverse cardiovascular events (MACE) including death, myocardial infarction, and target vessel revascularization.ResultsA total of 574 patients were followed for 30 months (25th to 75th percentile 18 to 46 months). Using receiver-operating characteristic curve analysis post-stenting FFR cutoff of ≤0.86 had the best predictive accuracy of MACE (17% vs. 23%; log-rank p = 0.02), whereas post-stenting Pd/Pa ≤0.96 was the best predictor of MACE (15% vs. 24%; log rank p = 0.0006). There was a significant interaction between post-PCI Pd/Pa and FFR on MACE risk such that patients with Pd/Pa ≤0.96 and FFR ≤0.86 had the highest event rate (25%), whereas those with Pd/Pa >0.96 and FFR >0.86 had the lowest event rate (15%), which was not different from patients with Pd/Pa >0.96 and FFR ≤0.86 (17%). In a fully adjusted Cox regression analysis, Pd/Pa was an independent predictor of MACE (hazard ratio: 2.07; 95% confidence interval: 1.3 to 3.3; p = 0.002).ConclusionsPost-PCI resting Pd/Pa is a powerful prognostic tool for MACE prediction. It adds complementary and incremental risk stratification over established factors including post-PCI FFR.     

Study Design of the Graft Patency After FFR-Guided Versus Angiography-Guided CABG Trial (GRAFFITI)

Clinical benefit of invasive functionally guided revascularization has been mostly investigated and proven for percutaneous coronary intervention. It has never been prospectively evaluated whether a systematic fractional flow reserve (FFR) assessment is also beneficial in guiding coronary artery bypass graft surgery (CABG). The objective of the GRAft patency after FFR-guided versus angiography-guIded CABG (GRAFFITI) trial was to compare an FFR-guided revascularization strategy to the traditional angiography-guided revascularization strategy for patients undergoing CABG. Patients were enrolled with significantly diseased left anterior descending or left main stem and at least one major coronary artery with angiographically intermediate stenosis (30–90% diameter stenosis) that was assessed by FFR. Thereafter, while the FFR values were kept concealed, cardiac surgeons decided their intended procedural strategy based on the coronary angiography alone. At this point, patients underwent 1:1 randomization to either an FFR-guided or an angiography-guided CABG strategy. In case the patient was randomized to angiography-guided arm, cardiac surgeons kept their intended procedural strategy, i.e., CABG was guided solely on the basis of the coronary angiography. In case the patient was randomized to the FFR-guided arm, FFR values were disclosed to the surgeons who revised the surgical protocol according to the functional significance of each coronary stenosis. The primary endpoint of the trial was the rate of graft occlusion at 12 months, assessed by coronary computed tomography or coronary angiography. The secondary endpoints were (1) length of postoperative hospital stay; (2) changes in surgical strategy depending upon FFR results (in FFR-guided group only); and (3) rate of major adverse cardiac and cerebrovascular events, i.e., composite of death, myocardial infarction, stroke, and any revascularization during the follow-up period. This study is the first prospective randomized trial investigating potential clinical benefits, associated with FFR-guided surgical revascularization. Trial registration: NCT01810224     

Clinical Implication of Quantitative Flow Ratio After Percutaneous Coronary Intervention for 3-Vessel Disease

ObjectivesThe aim of this study was to investigate the impact of post–percutaneous coronary intervention (PCI) quantitative flow ratio (QFR) on clinical outcomes in patients with de novo 3-vessel disease (3VD) treated with contemporary PCI.BackgroundThe clinical impact of post-PCI QFR in patients treated with state-of-the-art PCI for de novo 3VD is undetermined.MethodsAll vessels treated in the SYNTAX (SYNergy between percutaneous coronary intervention with TAXus and cardiac surgery) II trial were retrospectively screened and analyzed for post-PCI QFR. The primary endpoint of this substudy was vessel-oriented composite endpoint (VOCE) at 2 years, defined as the composite of vessel-related cardiac death, vessel-related myocardial infarction, and target vessel revascularization. The receiver-operating characteristic curve was used to calculate the optimal cutoff value of post-PCI QFR for predicting 2-year VOCE. All the analyzable vessels were stratified on the basis of the optimal cutoff value.ResultsA total of 968 vessels treated with PCI were screened. Post-PCI QFR was analyzable in 771 (79.6%) vessels. A total of 52 (6.7%) VOCEs occurred at 2 years. The mean value of post-PCI QFR was 0.91 ± 0.07. The diagnostic performance of post-PCI QFR to predict 2-year VOCE was moderate (area under the curve: 0.702; 95% confidence interval: 0.633 to 0.772), with the optimal cutoff value of post-PCI QFR for predicting 2-year VOCE 0.91 (sensitivity 0.652, specificity 0.635). The incidence of 2-year VOCE in the vessels with post-PCI QFR <0.91 (n = 284) was significantly higher compared with vessels with post-PCI QFR ≥0.91 (n = 487) (12.0% vs. 3.7%; hazard ratio: 3.37; 95% confidence interval: 1.91 to 5.97; p < 0.001).ConclusionsA higher post-PCI QFR value is associated with improved vessel-related clinical outcomes in state-of-the art PCI practice for de novo 3VD. Achieving a post-PCI QFR value ≥0.91 in all treated vessels should be a target when treating de novo 3VD. These findings require confirmation in future prospective trials.     

Measurement of fractional flow reserve in patients with multi-vessel coronary artery disease and borderline lesions prevents unnecessary revascularisation procedures

BACKGROUND: Patients with multi-vessel coronary artery disease (CAD) are selected for percutaneous coronary interventions (PCI) or surgical revascularisation. The appropriateness of "ad hoc" PCI of borderline lesions (<70% of lumen diameter) in patients with a multi-vessel CAD has not been proven. However, delayed PCI of another lesion and gaining additional information from non-invasive tests is not a widely accepted strategy. When left anterior descending (LAD) coronary artery is one of the affected vessels, selection for surgical revascularisation is most likely. AIM: To assess long-term outcome in patients with multi-vessel CAD and borderline lesions, including LAD, in whom fractional flow reserve (FFR) in all affected vessels was measured and used for selection for PCI or conservative treatment. METHODS: The study group consisted of 16 patients with stable angina (11 males, mean age 60+/-9 years) with 34 lesions localised in the main epicardial coronary arteries [LAD / left main (LM) / right coronary artery (RCA) / intermediate branch (IB) / circumflex artery (Cx) - 15/1/5/5/8] of which at least two were borderline stenoses. Each lesion underwent FFR measurement. "Ad hoc" PCI was performed when FFR was <0.75, and conservative therapy was instituted when FFR was >0.75. RESULTS: Of 34 lesions, in 8 (23%) the FFR value was <0.75 and these lesions were treated with PCI (LAD/IB/Cx - 3/2/3). In the remaining 26 (77%) lesions, FFR was >0.75 and conservative therapy was instituted. During the mean follow-up of 15+/-6 months (range 6-28 months, median 15 months) in 8 of 9 conservatively treated patients no aggravation of anginal symptoms nor other coronary events were observed. One patient developed acute myocardial infarction due to thrombus occluding a borderline LAD lesion. Of 8 lesions treated with PCI (baseline FFR = 0.63+/-0.10 vs post-PCI FFR = 0.92+/-0.08, p=0.0002), in one case an in-stent restenosis in LAD occurred 9 months after PCI. Of a total of 26 lesions which were conservatively treated (mean FFR 0.91+/-0.05), in 2 (7.7%) the progression of CAD was noted. CONCLUSIONS: In patients with multi-vessel CAD and borderline lesions, FFR measurement identifies those, who can be treated conservatively with a good long-term outcome, and prevents unnecessary PCI.     

Trans-Stent FFR Gradient as a Modifiable Integrant in Predicting Long-Term Target Vessel Failure

BackgroundFractional flow reserve (FFR) after percutaneous coronary intervention (PCI) is associated with long-term outcomes. Data relating FFR-based trans-stent gradient (TSG) after PCI to long-term outcomes are sparse.ObjectivesThe aim of this study was to test whether TSG is associated with adverse events at follow-up after PCI.MethodsData were gathered from a prospective registry evaluating 501 vessels in 416 patients with median follow-up period of 596 days. Primary endpoints were: 1) target vessel failure (TVF), including target vessel revascularization, and target vessel myocardial infarction after discharge; and 2) major adverse cardiac events (MACE) including TVF, target vessel revascularization, nontarget vessel MI, cardiac death.ResultsAfter PCI, median post-PCI FFR was 0.86 and median TSG was 0.04. TSG >0.04 was associated with increased rates of TVF (8.7% vs 2.9%; P = 0.014) and MACE (17.8% vs 9.2%; P = 0.02). Post-PCI FFR < 0.86 was associated with increased rates of TVF (6.1% vs 2.2%; P = 0.03) and MACE (16.5% vs 10%; P = 0.036). The vessel subgroup with high TSG and low FFR had significantly higher rates of TVF (10.2%; P = 0.02) and MACE (20.1%; P = 0.049) than vessels with: 1) high TSG and high FFR (TVF, 2.9%; MACE, 9.7%); 2) low TSG and low FFR (TVF, 3.8%; MACE, 11.3%); and 3) low TSG high FFR (TVF, 2.2%; MACE, 7.5%). In multivariate analysis, TSG was independently predictive of TVF.ConclusionsHigher TSG was an independent predictor of adverse events, particularly TVF, and identified a subgroup of patients at higher risk for poor outcomes. The combination of high TSG and low FFR showed significantly worse outcomes compared with an “ideal result” (high FFR and low TSG). These data support a recommendation to use TSG during FFR evaluation to determine the functional success of PCI.     

Physiological Distribution and Local Severity of Coronary Artery Disease and Outcomes After Percutaneous Coronary Intervention

ObjectivesThe aim of this study was to evaluate prognostic implications of physiological 2-dimensional disease patterns on the basis of distribution and local severity of coronary atherosclerosis determined by quantitative flow ratio (QFR) virtual pull back.BackgroundThe beneficial effect of percutaneous coronary intervention (PCI) is determined by physiological distribution and local severity of coronary atherosclerosis.MethodsThe study population included 341 patients who underwent angiographically successful PCI and post-PCI fractional flow reserve (FFR) measurement. Using pre-PCI virtual pull backs of QFR, physiological distribution was determined by pull back pressure gradient index, with a cutoff value of 0.78 to define predominant focal versus diffuse disease. Physiological local severity was assessed by instantaneous QFR gradient per unit length, with a cutoff value of ≥0.025/mm to define a major gradient. Suboptimal post-PCI physiological results were defined as both post-PCI FFR ≤0.85 and percentage FFR increase ≤15%. Clinical outcome was assessed by target vessel failure (TVF) at 2 years.ResultsQFR pull back pressure gradient index was correlated with post-PCI FFR (R = 0.423; P < 0.001), and instantaneous QFR gradient per unit length was correlated with percentage FFR increase (R = 0.370; P < 0.001). Using the 2 QFR-derived indexes, disease patterns were classified into 4 categories: predominant focal disease with and without major gradient (group 1 [n = 150] and group 2 [n = 21], respectively) and predominant diffuse disease with and without major gradient (group 3 [n = 115] and group 4 [n = 55], respectively). Proportions of suboptimal post-PCI physiological results were significantly different according to the 4 disease patterns (18.7%, 23.8%, 22.6%, and 56.4% from group 1 to group 4, respectively; P < 0.001). Cumulative incidence of TVF after PCI was significantly higher in patients with predominant diffuse disease (8.1% in group 3 and 9.9% in group 4 vs 1.4% in group 1 and 0.0% in group 2; overall P = 0.024).ConclusionsBoth physiological distribution and local severity of coronary atherosclerosis could be characterized without pressure-wire pull backs, which determined post-PCI physiological results. After successful PCI, TVF risk was determined mainly by the physiological distribution of coronary atherosclerosis. (Automated Algorithm Detecting Physiologic Major Stenosis and Its Relationship With Post-PCI Clinical Outcomes [Algorithm-PCI], NCT04304677; Influence of FFR on the Clinical Outcome After Percutaneous Coronary Intervention [PERSPECTIVE], NCT01873560)     

血流储备分数与冠状动脉造影指导不稳定型心绞痛患者临界病变介入治疗效果的比较

目的 分析血流储备分数（FFR）与冠状动脉造影（CAG）指导的不稳定型心绞痛患者临界病变介入治疗的效果.方法 回顾性分析2012年9月1日至2013年9月30日在北京大学人民医院心脏中心行CAG显示为临界病变且行FFR检查的不稳定型心绞痛患者,共收集41例患者的50处血管病变,与同时期行CAG的不稳定型心绞痛临界病变病例进行1：3匹配,分析其随访期间的主要不良心血管事件（包括心绞痛无缓解、再次靶血管血运重建、非致死性心肌梗死和心源性死亡）.结果 FFR介入治疗组共21例25处血管病变;FFR药物治疗组共20例25处血管病变;CAG介入治疗组共63例75处血管病变;CAG药物治疗组共60例75处血管病变.FFR介入治疗组术后的FFR平均值为（0.86±0.07）,有4例4处血管（16％）的术后FFR≥0.94,达到了介入治疗结果理想的标准;有13例17处血管（68％）的术后FFR在0.80～0.94的可接受范围内;其余4例4处血管（16％）的术后FFR＜0.80.FFR指导治疗的2组病例和CAG指导治疗的2组病例术后总的主要不良心血管事件（包括死亡、非致死性心肌梗死、再次靶血管血运重建和心绞痛缓解情况）差异有统计学意义（P=0.000）.在随访过程中4组均无心源性死亡病例,非致死性心肌梗死的发生率在各组间的差异无统计学意义.心绞痛缓解情况在FFR指导治疗的两组中最为明显,明显缓解的比例高于CAG指导治疗的两组,而明显缓解＋部分缓解的比例达到了100％,也高于CAG指导治疗的两组（P=0.002）,差异有统计学意义.再次靶血管血运重建的情况在FFR指导治疗的两组中也明显低于CAG指导治疗的两组,尤其是FFR药物治疗组无再次靶血管血运重建事件发生.而CAG药物治疗组在随访过程中由于心绞痛无明显缓解等原因再次行靶血管血运重建的比例最高（P=0.008）,差异有统计学意义.结论 采用FFR检查可以准确的识别不稳定型心绞痛患者临界病变是否缺血,用于指导介入治疗可以降低术后的主要不良心血管事件.