Fractional Flow Reserve Group Research Articles

FRACTIONAL FLOW RESERVE–GUIDED PCI IN PATIENTS WITH MULTI-VESSEL CORONARY ARTERY DISEASE

In multi-vessel coronary artery disease (CAD), there is insufficient data to support the use of fractional flow reserve (FFR) to guide treatment beyond candidates for coronary graft surgery or percutaneous coronary intervention. Objectives: The purpose of this study was to investigate whether the treatment based on FFR is more effective in lowering the ‘cumulative rate of death’, ‘myocardial infarction’, ‘stroke, or unexpected coronary revascularization in patients who have multi-vessel CAD than a ‘traditional strategy based on coronary angiography without FFR’. Methodology: A retrospective cross-sectional study involving 1200 participants, i-e, 607 in the control group and 593 in the FFR group. This study was conducted at the National Institute of Cardiovascular Diseases (NICVD) from June 2021 to July 2022. Multi-vessel CAD candidates were randomised (1 to 1) to either a conventional treatment plan without FFR or an intervention plan ‘based on FFR in all stenotic (≥50%) coronary arteries. ‘Revascularization (percutaneous coronary intervention or surgery)’ was recommended for FFR ≤0.80 lesions in the FFR group. A significant ‘adverse cardiac or cerebrovascular event at one year served as the primary outcome. Results: After a safety investigation and the enrollment of 1200 patients, the data safety and monitoring board decided to terminate the trial early. The results showed no appreciable variations in the frequencies of major adverse cardiac or cerebrovascular events among the FFR and control groups at the one-year monitoring, according to intention to treat. A 24-month extended follow-up confirmed no significant difference in all-cause mortality between the FFR group and the control group. More individuals were referred solely for medical care when FFR dramatically decreased the percentage of revascularised individuals. Conclusion: An FFR-guided approach reduced revascularisation rates compared to angiography only and almost doubled the rate of OMT alone among individuals with multi-vessel coronary artery disease. However, the FFR-guided approach had no discernible impact on the clinical results at one year, determined mainly by the SYNTAX score and left ventricular function. The current study indicates that while FFR alone does not affect clinical results, it does assist in selecting the best revascularisation approach.

Physiology- or Imaging-Guided Strategies for Intermediate Coronary Stenosis

Treatment strategies for intermediate coronary lesions guided by fractional flow reserve (FFR) and intravascular ultrasonography (IVUS) have shown comparable outcomes. Identifying low-risk deferred vessels to ensure the safe deferral of percutaneous coronary intervention (PCI) and high-risk revascularized vessels that necessitate thorough follow-up can help determine optimal treatment strategies. To investigate outcomes according to treatment types and FFR and IVUS parameters after FFR- or IVUS-guided treatment. This cohort study included patients with intermediate coronary stenosis from the Fractional Flow Reserve and Intravascular Ultrasound-Guided Intervention Strategy for Clinical Outcomes in Patients With Intermediate Stenosis (FLAVOUR) trial, an investigator-initiated, prospective, open-label, multicenter randomized clinical trial that assigned patients into an IVUS-guided strategy (which recommended PCI for minimum lumen area [MLA] ≤3 mm2 or 3 mm2 to 4 mm2 with plaque burden [PB] ≥70%) or an FFR-guided strategy (which recommended PCI for FFR ≤0.80). Data were analyzed from November to December 2022. FFR or IVUS parameters within the deferred and revascularized vessels. The primary outcome was target vessel failure (TVF), a composite of cardiac death, target vessel myocardial infarction, and revascularization at 2 years. A total of 1619 patients (mean [SD] age, 65.1 [9.6] years; 1137 [70.2%] male) with 1753 vessels were included in analysis. In 950 vessels for which revascularization was deferred, incidence of TVF was comparable between IVUS and FFR groups (3.8% vs 4.1%; P = .72). Vessels with FFR greater than 0.92 in the FFR group and MLA greater than 4.5 mm2 or PB of 58% or less in the IVUS group were identified as low-risk deferred vessels, with a decreased risk of TVF (hazard ratio [HR], 0.25 [95% CI, 0.09-0.71]; P = .009). In 803 revascularized vessels, the incidence of TVF was comparable between IVUS and FFR groups (3.6% vs 3.7%; P = .95), which was similar in the revascularized vessels undergoing PCI optimization (4.2% vs 2.5%; P = .31). Vessels with post-PCI FFR of 0.80 or less in the FFR group or minimum stent area of 6.0 mm2 or less or with PB at stent edge greater than 58% in the IVUS group had an increased risk for TVF (HR, 7.20 [95% CI, 3.20-16.21]; P < .001). In this cohort study of patients with intermediate coronary stenosis, FFR- and IVUS-guided strategies showed comparable outcomes in both deferred and revascularized vessels. Binary FFR and IVUS parameters could further define low-risk deferred vessels and high-risk revascularized vessels.

Clinical Outcomes of Deferred Lesions by IVUS Versus FFR-Guided Treatment Decision.

There are limited data regarding the safety of deferral of percutaneous coronary intervention based on intravascular ultrasound (IVUS) findings. The current study sought to compare the prognosis between deferred lesions based on IVUS and fractional flow reserve (FFR)-guided treatment decision. This study is a post hoc analysis of the FLAVOUR randomized trial (Fractional Flow Reserve and Intravascular Ultrasound for Clinical Outcomes in Patients With Intermediate Stenosis) that compared 2-year clinical outcomes between IVUS- and FFR-guided treatment decision on intermediate coronary artery lesions using predefined criteria. In both IVUS and FFR groups, vessels were classified into deferred or revascularized vessels, and patients were classified as those with or without deferred lesions. Vessel-oriented composite outcomes (cardiac death, target vessel myocardial infarction, or target vessel revascularization) in deferred vessels and patient-oriented composite outcomes (death, myocardial infarction, or any revascularization) in patients with deferred lesions were compared between the IVUS and FFR groups. A total of 1682 patients and 1820 vessels were analyzed, of which 922 patients and 989 vessels were deferred. At 2 years, there was no difference in the cumulative incidence of vessel-oriented composite outcomes in deferred vessels between IVUS (n=375) and FFR (n=614) groups (3.8% versus 4.1%; hazard ratio, 0.91 [95% CI, 0.47-1.75]; P=0.77). The risk of vessel-oriented composite outcomes was comparable between deferred and revascularized vessels following treatment decision by IVUS (3.8% versus 3.5%; hazard ratio, 1.09 [95% CI, 0.54-2.19]; P=0.81) and FFR (4.1% versus 3.6%; hazard ratio, 1.14 [95% CI, 0.56-2.32]; P=0.72). In comparison of patient-oriented composite outcomes in patients with deferred lesions, there was no significant difference between the IVUS (n=357) and FFR (n=565) groups (6.2% versus 5.9%; hazard ratio, 1.05 [95% CI, 0.61-1.80]; P=0.86). In patients with intermediate coronary artery stenosis, deferral of percutaneous coronary intervention based on IVUS-guided treatment decision showed comparable risk of clinical events with FFR-guided treatment decision. URL: https://www.clinicaltrials.gov; Unique identifier: NCT02673424.

Clinical outcomes of deferred lesions by IVUS versus FFR-guided treatment decision: the FLAVOUR trial substudy

Abstract Background There is limited data regarding the safety of deferral of percutaneous coronary intervention (PCI) based on intravascular ultrasound (IVUS) findings. Current study sought to compare the prognosis between deferred lesions based on IVUS and FFR (fractional flow reserve)-guided treatment decision. Methods Study population was derived from FLAVOUR trial which is a multinational, open-label, randomized, and non-inferiority trial that compared 2-year clinical outcomes between IVUS and FFR-guided treatment decision using predefined criteria. In both IVUS and FFR groups, vessels were classified into deferred or revascularized vessels, and patients into those with or without deferred lesion. Vessel-oriented composite outcomes (VOCO) (cardiac death, target-vessel myocardial infarction, or target-vessel revascularization) in deferred vessels and patient-oriented composite outcomes (POCO) (death, myocardial infarction, or any revascularization) in patients with deferred lesion were compared between IVUS and FFR group. Results A total of 1682 patients and 1820 vessels were analyzed. At 2 years, there is no difference in cumulative incidence of VOCO in deferred vessels between IVUS and FFR groups (3.8% vs. 4.1%; hazard ratio [HR] 0.91; 95% confidence interval [CI] 0.47-1.75; P=0.771). The risk of VOCO was comparable between deferred and revascularized vessels following both IVUS (3.8% vs. 3.5%; HR 1.09; 95% CI 0.54-2.19; P=0.813) and FFR-guided treatment decision (4.1% vs. 3.6%; HR 1.14; 95% CI 0.56-2.32; P=0.715). In comparison of POCO in patients with deferred lesion, there was no significant difference between IVUS and FFR groups (6.2% vs. 5.9%; HR 1.05; 95% CI 0.61-1.80; P=0.856). Conclusion In patients with intermediate coronary artery stenosis, deferral of PCI based on IVUS-guided treatment decision showed comparable risk of clinical events with FFR-guided treatment decision.

Discordance between quantitative coronary angiography and fractional flow reserve or intravascular ultrasound: a substudy of the FLAVOUR trial

Abstract Background Discrepancies between quantitative coronary angiography (QCA) and fractional flow reserve (FFR) or intravascular ultrasound (IVUS) are often observed in coronary lesions with intermediate stenosis. Objectives We investigated the impact of physiology- or intracoronary imaging-directed revascularization strategies on clinical outcomes in patients with discordant coronary lesions between QCA and FFR or IVUS. Methods This study was a post hoc analysis of the FLAVOUR study, an investigator-initiated, prospective, randomized, open-label, multinational trial performed at 18 sites in Korea and China. In the FLAVOUR study, 200 patients with ≥60% diameter stenosis (DS) deferred percutaneous coronary intervention (PCI) according to FFR &amp;gt; 0.8 (n=141) or a minimal lumen area &amp;gt; 3 mm2 or 3-4 mm2 with a plaque burden &amp;lt;70% on IVUS whereas 351 patients with &amp;lt;60% DS performed PCI according to positive FFR (n=118) or positive IVUS (n=233) results. The primary outcome was a patient-oriented composite outcome (POCO), a composite of death, myocardial infarction, or revascularization. Results The incidence of discordance was 28.1% in the FFR group and 32.4% in the IVUS group. At 24 months, among patients with ≥60% DS, the incidence of POCO was similar between FFR-guided and IVUS-guided deferral strategies (4.4% vs. 3.4%, p=0.757). Among patients with &amp;lt;60% DS, FFR-directed or IVUS-directed PCI did not differ in the POCO incidence (5.2% vs. 2.6%, p=0.207). However, FFR-guided PCI showed a higher incidence of periprocedural myocardial infarction than IVUS-guided PCI in &amp;lt;60% DS lesions (2.6% vs. 0.0%, p=0.014). Conclusions In patients with discordant intermediate stenosis between QCA and FFR or IVUS, physiology- and imaging-directed revascularization strategies are comparable concerning POCO at 24 months.

Long-term association of post stent fractional flow reserve with clinical events

Abstract Background Low fractional flow reserve (FFR) after percutaneous coronary intervention (PCI) is associated with procedural factors in the stented segment and residual disease in the non-stented segment. Even the prognostic value of post-PCI FFR has been reported, its long-term clinical relevance has not been thoroughly investigated. Purpose We sought to investigate the long-term prognostic value of post-PCI FFR and its relative significance on future events in stented and non-stented segments. Methods The International Post-PCI FFR extended registry (NCT04684043) followed the 2,200 patients who underwent PCI and measured post-PCI FFR between June 2011 and May 2018. The primary outcome was target vessel failure (TVF), a composite of cardiac death, target vessel myocardial infarction (TVMI), and target vessel revascularization (TVR) at 5 years. The secondary outcomes were a composite of cardiac death or TVMI at 5 years. Results The median value of post-PCI FFR of target vessels was 0.89 (IQR 0.84-0.93). The optimal cut-off value of post-PCI FFR for predicting TVF was 0.81, and that for predicting cardiac death or TVMI was 0.76, respectively. The cumulative incidence of TVF was significantly higher in the low post-PCI group (20.5%) than in the high post-PCI FFR group (10.3%) (adjusted hazard ratio [HR] 2.11, 95% confidence interval [CI] 1.56-2.86, p&amp;lt;0.001). The cumulative incidence of cardiac death or TVMI was also significantly higher in the low post-PCI FFR group (7.3%) than in the high post-PCI FFR group (3.2%) (adjusted HR 2.34, 95% CI 1.12-4.91, p=0.024). Landmark analysis at 2 years showed that the impact of post-PCI FFR on TVF was consistently found during the first 2 years (adjusted HR of low post-PCI FFR 2.22, 95% CI 1.54-3.21, p&amp;lt;0.001) and thereafter (adjusted HR of low post-PCI FFR 1.96, 95% CI 1.14-3.36, p&amp;lt;0.001). However, the impact of post-PCI FFR on cardiac death or TVMI was more significant after 2 years of follow-up (adjusted HR of low post-PCI FFR 2.01, 95% CI 0.66-6.11, p=0.217 for the first 2 years and adjusted HR of low-post PCI FFR 2.81, 95% CI 1.04-7.60, p=0.042). The cumulative incidence of TVR was 9.5% for 5 years, and 61.0% of TVRs occurred in the stented segment. However, the proportion of TVRs in the non-stented segment increased along with the decrease of post-PCI FFR (35.3% in post-PCI FFR more than 0.90, 34.1% in post-PCI FFR 0.81-0.90, 43.8% in post-PCI FFR 0.71-0.80, and 66.7% in post-PCI FFR 0.70 and less than 0.70, p-for trend&amp;lt;0.001). Conclusions The long-term outcome results of the Internation Post-PCI FFR Extended registry showed that the prognostic impact of post-PCI FFR on TVF was consistently found along with the follow-up. However, that of post-PCI FFR on cardiac death or TVMI was more prominent during the late period of follow-up. In addition, clinical event distribution was different according to post-PCI FFR values.

Intravascular Ultrasound vs. Fractional Flow Reserve for Percutaneous Coronary Intervention Optimization in Long Coronary Artery Lesions.

intravascular ultrasound (IVUS) and fractional flow reserve (FFR) have both been shown to be superior to angiography in optimizing percutaneous coronary intervention (PCI). However, there is still a lack of comparative studies between PCI optimization using physiology and intravascular imaging head-to-head. The aim of this study was to compare the effectiveness of FFR and IVUS PCI optimization strategies on the functional PCI result (assessed with FFR) immediately post-PCI and at 9-12 months after the treatment of long coronary lesions. This was a single-center study comparing post-PCI FFR between two different PCI optimization strategies (FFR and IVUS). The study included 154 patients who had hemodynamically significant long lesions, necessitating a stent length of 30 mm or more. The procedural outcomes were functional PCI result immediately post-PCI and at 9-12 months after treatment. Clinical outcomes included target vessel failure (TVF) and functional target vessel restenosis rate during follow-up. Baseline clinical characteristics and FFR (0.65 [0.55-0.71]) did not differ significantly between the two groups and the left anterior descending artery was treated in 82% of cases. The FFR optimization strategy resulted in a significantly shorter stented segment (49 mm vs. 63 mm, p = 0.001) compared to the IVUS optimization strategy. Although the rates of optimal functional PCI result (FFR > 0.9) did not significantly differ between the FFR and IVUS optimization strategies, a proportion of patients in the FFR group (12%) experienced poor post-PCI functional outcome with FFR values ≤ 0.8, which was not observed in the IVUS group. At the 9-12 month follow-up, 20% of patients in the FFR group had target-vessel-related myocardial ischemia, compared to 6% in the IVUS group. The rates of TVF and functional target vessel restenosis during follow-up were also numerically higher in the FFR optimization group. The use of FFR PCI optimization strategy in the treatment of long coronary artery lesions is associated with a higher incidence of poor functional PCI result and larger myocardial ischemia burden at follow-up compared to the IVUS optimization strategy. However, this discrepancy did not translate into a statistically significant difference in clinical outcomes. This study highlights the importance of using IVUS to optimize long lesions functional PCI outcomes.

Characteristics and correlation between FFR and RFR of non-culprit lesions in acute myocardial infarction

Background: While resting-full cycle ratio (RFR) is strongly correlated with fractional flow reserve (FFR), it has been extensively examined in stable coronary artery disease. However, there is a lack of evaluation regarding non-culprit lesions in patients with acute myocardial infarction (AMI). Objectives: To investigate the clinical characteristics and to identify the correlation and discordance between FFR and RFR among AMI patients with non-culprit lesions. Methods: A retrospective cohort study was conducted in 44 AMI patients who underwent percutaneous coronary intervention (PCI) for culprit lesions and &gt; 90% stenosis non-culprit lesions. With non-culprit stenosis from 50 - 90%, 23 patients had simultaneous measurements of both FFR and RFR, and 17 patients underwent PCI based on FFR ≤ 0.8. Results: Approximately 79.5% of patients exhibited a presence of two or more risk factors associated with coronary artery disease. In 44 culprit lesions, 40.9% of cases located in the RCA branch, while in 46 nonculprit lesions, 61.4% of cases were found in the LAD branch. The average FFR among 44 patients was 0.82 ± 0.13. There was a significant improvement in FFR after PCI (0.89 ± 0.07) compared to pre-PCI (0.70 ± 0.11) in 17 patients with p &lt; 0.001. The mean RFR among the 23 patients was 0.84 ± 0.12. Among 12 patients with positive RFR, RFR after PCI (0.95 ± 0.04) was higher than pre-PCI (0.78 ± 0.13) with p = 0.002. Furthermore, pre-PCI RFR showed a strong positive correlation with FFR (r = 0.662, p = 0.001). The discordant rate between RFR and FFR was 26.8%. The discordant rate of FFR and RFR measurements was 26.1%. Additionally, the left anterior descending artery (LAD) was assumed as a predictor of discordance in the high FFR group (FFR &gt; 0.80) and low RFR group (RFR ≤ 0.89). Conclusion: The low discordance rate and strong correlation between FFR and RFR suggest their complementary roles in the assessment of intermediate non-culprit lesions in patients with AMI. Key words: fractional flow reserve, resting full-cycle ratio, non-culprit lesion, correlation, acute myocardial infarction.

Prognostic Assessment of Fractional Flow Reserve in Different Strata in Patients with Coronary Artery Disease.

There are limited real-world data on the clinical course of untreated coronary lesions according to their functional severity. To evaluate the 5-year clinical outcomes of patients with revascularized lesions with fractional flow reserve (FFR) ≤ 0.8 and patients with non-revascularized lesions with FFR > 0.8. The FFR assessment was performed in 218 patients followed for up to 5 years. Participants were classified based on FFR into ischemia group (≤ 0.8, intervention group, n = 55), low-normal FFR group (> 0.8-0.9, n = 91), and high-normal FFR group (> 0.9, n = 72). The primary endpoint was major adverse cardiac events (MACEs), a composite of death, myocardial infarction, and need for repeat revascularization. The significance level was set at 0.05; therefore, results with a p-value < 0.05 were considered statistically significant. Most patients were male (62.8%) with a mean age of 64.1 years. Diabetes was present in 27%. On coronary angiography, the severity of stenosis was 62% in the ischemia group, 56.4% in the low-normal FFR group, and 54.3% in the high-normal FFR group (p<0.05). Mean follow-up was 3.5 years. The incidence of MACEs was 25.5%, 13.2%, and 11.1%, respectively (p=0.037). MACE incidence did not differ significantly between the low-normal and high-normal FFR groups. Patients with FFR indicative of ischemia had poorer outcomes than those in non-ischemia groups. There was no difference in the incidence of events between the low-normal and high-normal FFR groups. Long-term studies with a large sample size are needed to better assess cardiovascular outcomes in patients with moderate coronary stenosis with FFR values between 0.8 and 1.0.

Factors affecting short- and long-term survival of patients with acute coronary syndrome treated invasively using intravascular ultrasound and fractional flow reserve: Analysis of data from the Polish Registry of Acute Coronary Syndromes 2017-2020.

Intravascular ultrasound (IVUS) and fractional flow reserve (FFR) are invasive procedures increasingly used in treating acute coronary syndrome (ACS). This study aimed to evaluate the frequency of IVUS and FFR use in patients with ACS in Poland and to assess the safety of these procedures as well as their impact on short- and long-term survival. This retrospective study included 103849 patients enrolled in the Polish Registry of Acute Coronary Syndromes in 2017-2020. IVUS was performed in 1727 patients, FFR in 1537 patients, and both procedures in 37 patients. The frequency of performing FFR in ACS patients increased over the years from 1.3% to 1.8% (P <0.0001) and IVUS from 1.7% to 2.3% (P <0.0001). In the FFR and/or IVUS group, a similar incidence of stroke, reinfarction, target vessel revascularization, and major bleeding was observed while in-hospital mortality was lower (0% for IVUS + FFR vs. 0.9% for FFR vs. 2.3% for IVUS vs. 3.7 for no procedure; P <0.0001). FFR and IVUS did not affect the 30-day and one-year prognosis. In recent years, the number of FFR and IVUS procedures performed in patients with ACS in Poland has increased. There was lower in-hospital mortality in the FFR and/or IVUS group in ACS patients, and no differences in the incidence of stroke, reinfarction, target vessel revascularization, and major bleeding were observed. Performing FFR and IVUS in ACS patients does not significantly affect 30-day or one-year mortality.

Clinical Outcome of Revascularization Deferral With Instantaneous Wave-Free Ratio and Fractional Flow Reserve: A 5-Year Follow-Up Substudy From the iFR-SWEDEHEART Trial.

Background Although physiology-based assessment of coronary artery stenosis using instantaneous wave-free ratio (iFR) and fractional flow reserve (FFR) are established methods of guiding coronary revascularization, its clinical outcome in long-term deferral needs further evaluation, especially with acute coronary syndrome as a clinical presentation. The aim was to evaluate the long-term clinical outcome of deferral of revascularization based on iFR or FFR. Methods and Results This is a substudy of the iFR-SWEDEHEART (Instantaneous Wave-Free Ratio Versus Fractional Flow Reserve in Patients With Stable Angina Pectoris or Acute Coronary Syndrome) randomized clinical trial, where patients deferred from revascularization from each study arm were selected. Nine hundred eight patients deferred from coronary revascularization with iFR (n=473) and FFR (n=435) were followed for 5 years. The national quality registry, SWEDEHEART (Swedish Web-System for Enhancement and Development of Evidence-Based Care in Heart Disease Evaluated According to Recommended Therapies), was used for patient data collection and clinical follow-up. The end point was major adverse cardiac events and their individual components all-cause death, cardiovascular death, noncardiovascular death, nonfatal myocardial infarction, and unplanned revascularization. No significant difference was found in major adverse cardiac events (iFR 18.6% versus FFR 16.8%; adjusted hazard ratio, 1.08 [95% CI, 0.79-1.48]; P=0.63) or their individual components. Conclusions No differences in clinical outcomes after 5-year follow-up were noted when comparing iFR versus FFR as methods for deferral of coronary revascularization in patients presenting with stable angina pectoris and acute coronary syndrome. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT02166736.

Abstract 15572: Utility Trends and Outcomes of Fractional Flow Reserve (FFR) in Diagnostic Coronary Angiograms for Patients With Stable Angina: National Readmission Database (2016-2019)

Background: In patients with intermediate severity stenosis in a coronary artery, FFR has become the gold standard to measure myocardial ischemia and facilitate the clinical decision regarding the need for revascularization. However, when compared to angiography, it is still underutilized in clinical practice to guide PCI. Our research investigates the difference in outcomes between angiography with versus without the measurement of FFR in real-world data. Methods: National readmission databases 2016-2019 were used to identify patients with CAD undergoing coronary angiogram with versus without FFR using ICD-10 codes. We excluded cases who had Acute Coronary Syndrome (ACS), revascularization by PCI or CABG in the index admission or was performed in the last 6 months of each year to allow time for follow-up. Primary outcomes of the study were 6-months ACS admissions, Secondary outcomes include 6-months revascularization by PCI or CABG and mortality. We matched both cohorts using propensity score matching (PSM) and performed logistic regression to compute the odds ratios (ORs) and corresponding 95% confidence intervals (CI). Results: Out of 1,039,508 angiography procedures done in the USA, 68,767 (6.6%) cases FFR were used, trends of FFR utilization are noted in figure 1. After propensity score matching, our cohort included 31,469 patients with angiography alone and 31,637 angiography with FFR. At six months of follow-up, there was no significant difference in readmission rates due to ACS, OR 0.84 (95%, 0.69-1.03, P=0.098) or revascularization by PCI/CABG, OR: 1.07 (95% CI, 0.92-1.23, P=0.39). However, there was a significant reduction in mortality in the FFR group compared to the angiography alone group OR 0.81 (95% CI, 0.69-0.94, P&lt;0.01). Conclusion: In this nationally representative cohort, our study shows that angiography with FFR is associated with decreased mid-term mortality. In the USA, FFR utilization rate during Angiography remains minuscule (6.6%).

Comparison of Six Different Percutaneous Coronary Intervention Guidance Modalities.

Background: New randomized trials and modalities in guiding percutaneous coronary intervention (PCI) have become available. Objective: We aimed to compare the clinical outcomes of coronary angiography (CAG), intravascular ultrasound (IVUS), optical coherence tomography (OCT), fractional flow reserve (FFR), instantaneous wave-free ratio (iFR), and optical frequency domain imaging (OFDI)-guided PCI. Methods: A network meta-analysis was performed to compare different PCI guidance modalities. The clinical outcomes included major adverse cardiovascular events (MACE), all-cause death, myocardial infarction (MI), and target vessel/lesion revascularization (TVR/TLR). Odds ratio (OR) and corresponding 95% credible interval (CrI) were calculated. Results: Thirty-six randomized trials, including 19,042 patients, were included. In comparison with CAG, IVUS significantly reduced MACE (OR: 0.71; 95% CrI: 0.57 to 0.86) and TVR/TLR (OR: 0.53; 95% CrI: 0.43 to 0.66). MACE (OR: 1.44; 95% CrI: 1.02 to 2.08) and TVR/TLR (OR: 1.87; 95% CrI: 1.04 to 3.71) were significantly increased in the FFR group, compared with IVUS group. There were no significant differences in MACE or TVR/TLR among the left guidance modality comparisons. Differences in all-cause death or MI were not observed in any comparisons. Conclusions: IVUS could reduce MACE and TVR/TLR, compared with CAG or FFR. Therefore, IVUS may be the optimal modality in guiding PCI.

Prognosis and Medical Cost of Measuring Fractional Flow Reserve in Percutaneous Coronary Intervention

There are limited data regarding comparative prognosis and medical cost between fractional flow reserve (FFR)-based and angiography-based percutaneous coronary intervention (PCI) among revascularized patients. This study evaluates prognosis and medical cost of FFR use in revascularized patients by PCI. Using the National Health Insurance Service database, stable or unstable angina patients who underwent PCI from 2011 to 2017 were evaluated. Eligible patients were divided into 2 groups according to use of FFR in PCI. Primary outcome was a composite of all-cause death or spontaneous myocardial infarction (MI). Secondary outcomes included individual components of the primary outcome, unplanned revascularization, and medical costs. Among 134,613 eligible patients, PCI was performed based on angiography (n=129,497) and FFR (n=5,116). During the study period, both the annual number and proportion of use of FFR in PCI increased (all P for trend<0.001). The FFR group showed significantly lower risk of the primary outcome (7.0% vs 9.5%; P< 0.001), all-cause death (5.8% vs 7.7%; P = 0.001), and spontaneous MI (1.6% vs 2.2%; P = 0.022) than the angiography group. Although the FFRgroup showed higher medical cost during index admission than angiography group (median: $6,265.10 vs $5,385.60; P< 0.001), cumulative medical cost after index admission was significantly lower ($2,696.50 vs. $3,142.10; P< 0.001). Use of FFR in PCI in stable or unstable angina patients showed significantly lower risk of all-cause death and spontaneous MI compared to angiography-based PCI. Although the FFR group had higher initial medical cost than the angiography group, cumulative medical cost after index admission was significantly lower.

Relationship Between Coronary Lesion Severity Detected in Fractional Flow Reserve with Monocyte/High-Density Lipoprotein, Neutrophil/ Lymphocyte, Lymphocyte/Monocyte, and Platelet/ Lymphocyte Ratios: Which Is Most Important?

Objective: In this study, in patients with moderate coronary lesions evaluated in coronary angiography, fractional flow reserve by lesion severity, we aimed to determine the relationship between neutrophil/lymphocyte ratio, platelet/lymphocyte ratio, lymphocyte/monocyte ratio, and monocyte/high-density lipoprotein cholesterol ratio, which has been recently expressed as a predictor of cardiovascular disease risk. Methods: Stenosis with a fractional flow reserve of &lt;0.80 was considered functionally severe. According to fractional flow reserve lesion severity, a total of 131 patients were analyzed, with fractional flow reserve &gt; 0.8 (group 1) and fractional flow reserve &lt; 0.8 (group 2). Patients with acute coronary syndrome, severe arrhythmia, hemodynamic instability, history of previous revascularization, severe renal and hepatic failure, active infection, malignancy, hematologic disease, familial history of hyperlipidemia, rheumatologic disease, life expectancy &lt;1 year, and age &lt;18 and &gt;90 years were excluded from the study. Results: There was a statistically significant difference between monocyte/high-density lipoprotein cholesterol ratio, neutrophil /lymphocyte ratio, lymphocyte/monocyte ratio, and platelet/lymphocyte ratio, and fractional flow reserve groups (P &lt;.001). Univariate and multivariate regression analyses were applied among the factors affecting the severity of the lesion detected in fractional flow reserve. Monocyte/high-density lipoprotein cholesterol ratio (odds ratio, 1.25; 95% CI, 1.05-1.47; P =.004), neutrophil/lymphocyte ratio (odds ratio, 3.15; 95% CI, 1.51-6.57; P &lt;.001), hemoglobin A1c (odds ratio, 11.5; 95% CI, 2.76-48.4; P&nbsp;=.001), and lymphocyte/monocyte ratio (odds ratio, 0.27; 95% CI, 0.16-0.44; P =.002) were found to be independent predictors. Conclusions: In this study, we would like to emphasize that simple, fast, and low-cost methods such as monocyte/high-densit y lipoprotein cholesterol ratio, neutrophil/lymphocyte ratio, lymphocyte/monocyte ratio, and platelet/lymphocyte ratio can be parameters related to lesion severity detected in fractional flow reserve. These parameters can be widely used as they are easily accessible and repeatable.

Fractional Flow Reserve or Intravascular Ultrasonography to Guide PCI

BackgroundIn patients with coronary artery disease who are being evaluated for percutaneous coronary intervention (PCI), procedures can be guided by fractional flow reserve (FFR) or intravascular ultrasonography (IVUS) for decision making regarding revascularization and stent implantation. However, the differences in clinical outcomes when only one method is used for both purposes are unclear.MethodsWe randomly assigned 1682 patients who were being evaluated for PCI for the treatment of intermediate stenosis (40 to 70% occlusion by visual estimation on coronary angiography) in a 1:1 ratio to undergo either an FFR-guided or IVUS-guided procedure. FFR or IVUS was to be used to determine whether to perform PCI and to assess PCI success. In the FFR group, PCI was to be performed if the FFR was 0.80 or less. In the IVUS group, the criteria for PCI were a minimal lumen area measuring either 3 mm2 or less or measuring 3 to 4 mm2 with a plaque burden of more than 70%. The primary outcome was a composite of death, myocardial infarction, or revascularization at 24 months after randomization. We tested the noninferiority of the FFR group as compared with the IVUS group (noninferiority margin, 2.5 percentage points).ResultsThe frequency of PCI was 44.4% among patients in the FFR group and 65.3% among those in the IVUS group. At 24 months, a primary-outcome event had occurred in 8.1% of the patients in the FFR group and in 8.5% of those in the IVUS group (absolute difference, −0.4 percentage points; upper boundary of the one-sided 97.5% confidence interval, 2.2 percentage points; P=0.01 for noninferiority). Patient-reported outcomes as reported on the Seattle Angina Questionnaire were similar in the two groups.ConclusionsIn patients with intermediate stenosis who were being evaluated for PCI, FFR guidance was noninferior to IVUS guidance with respect to the composite primary outcome of death, myocardial infarction, or revascularization at 24 months. (Funded by Boston Scientific; FLAVOUR ClinicalTrials.gov number, NCT02673424.)

Fractional Flow Reserve (FFR) and Resting Index (dPR) Reproducibility With a Fiber-Optic Pressure Wire (Readi-Epic 14)

There are limited data regarding comparative prognosis and medical cost between fractional flow reserve (FFR)–based and angiography-based percutaneous coronary intervention (PCI) among revascularized patients.This study evaluates prognosis and medical cost of FFR use in revascularized patients by PCI.Using the National Health Insurance Service database, stable or unstable angina patients who underwent PCI from 2011 to 2017 were evaluated. Eligible patients were divided into 2 groups according to use of FFR in PCI. Primary outcome was a composite of all-cause death or spontaneous myocardial infarction (MI). Secondary outcomes included individual components of the primary outcome, unplanned revascularization, and medical costs.Among 134,613 eligible patients, PCI was performed based on angiography (n = 129,497) and FFR (n = 5,116). During the study period, both the annual number and proportion of use of FFR in PCI increased (all P for trend <0.001). The FFR group showed significantly lower risk of the primary outcome (7.0% vs 9.5%; P < 0.001), all-cause death (5.8% vs 7.7%; P = 0.001), and spontaneous MI (1.6% vs 2.2%; P = 0.022) than the angiography group. Although the FFR group showed higher medical cost during index admission than angiography group (median: $6,265.10 vs $5,385.60; P < 0.001), cumulative medical cost after index admission was significantly lower ($2,696.50 vs. $3,142.10; P < 0.001).Use of FFR in PCI in stable or unstable angina patients showed significantly lower risk of all-cause death and spontaneous MI compared to angiography-based PCI. Although the FFR group had higher initial medical cost than the angiography group, cumulative medical cost after index admission was significantly lower.

5-Year Outcomes of PCI Guided by Measurement of Instantaneous Wave-Free Ratio Versus Fractional Flow Reserve

BackgroundInstantaneous wave-free ratio (iFR) is a coronary physiology index used to assess the severity of coronary artery stenosis to guide revascularization. iFR has previously demonstrated noninferior short-term outcome compared to fractional flow reserve (FFR), but data on longer-term outcome have been lacking. ObjectivesThe purpose of this study was to investigate the prespecified 5-year follow-up of the primary composite outcome of all-cause mortality, myocardial infarction, and unplanned revascularization of the iFR-SWEDEHEART trial comparing iFR vs FFR in patients with chronic and acute coronary syndromes. MethodsiFR-SWEDEHEART was a multicenter, controlled, open-label, registry-based randomized clinical trial using the Swedish Coronary Angiography and Angioplasty Registry for enrollment. A total of 2,037 patients were randomized to undergo revascularization guided by iFR or FFR. ResultsNo patients were lost to follow-up. At 5 years, the rate of the primary composite endpoint was 21.5% in the iFR group and 19.9% in the FFR group (HR: 1.09; 95% CI: 0.90-1.33). The rates of all-cause death (9.4% vs 7.9%; HR: 1.20; 95% CI: 0.89-1.62), nonfatal myocardial infarction (5.7% vs 5.8%; HR: 1.00; 95% CI: 0.70-1.44), and unplanned revascularization (11.6% vs 11.3%; HR: 1.02; 95% CI: 0.79-1.32) were also not different between the 2 groups. The outcomes were consistent across prespecified subgroups. ConclusionsIn patients with chronic or acute coronary syndromes, an iFR-guided revascularization strategy was associated with no difference in the 5-year composite outcome of death, myocardial infarction, and unplanned revascularization compared with an FFR-guided revascularization strategy. (Evaluation of iFR vs FFR in Stable Angina or Acute Coronary Syndrome [iFR SWEDEHEART]; NCT02166736)

Five-Year Outcomes After Fractional Flow Reserve–Based Deferral of Revascularization in Chronic Coronary Syndrome: Final Results From the J-CONFIRM Registry

Little large-scale data is available about the long-term (beyond 3 years) clinical outcomes after fractional flow reserve (FFR)-based deferral of revascularization in clinical practice. We sought to assess the 5-year outcomes after deferral of revascularization based on FFR. The J-CONFIRM registry (Long-Term Outcomes of Japanese Patients With Deferral of Coronary Intervention Based on Fractional Flow Reserve in Multicenter Registry) prospectively enrolled 1263 patients with 1447 lesions in whom revascularization was deferred based on FFR from 28 Japanese centers. The primary study end point was the cumulative 5-year incidence of target vessel failure (TVF), including cardiac death, target vessel-related myocardial infarction, and clinically driven target vessel revascularization. Five-year follow-up was completed in 92.2% of patients. The 5-year TVF rate was 11.6% in deferred lesions, mainly driven by clinically driven target vessel revascularization (9.8%). Cardiac death and target vessel-related myocardial infarction were 1.9% and 0.95%, respectively. Cumulative 5-year incidence of TVF was similar between the FFR 0.75 to 0.80 and 0.81 to 0.85 groups even after adjustment for baseline characteristics (12.2% versus 13.0%, inverse probability-weighted hazard ratio, 0.86 [95% CI, 0.46-1.60]; P=0.63). Compared with the almost normal FFR (0.86-1.00) group, the significant (<0.75) and borderline (0.75-0.85) FFR groups showed a higher incidence of TVF at 5 years (29.9% versus 12.8% versus 8.6%, P<0.001). Independent predictors of the 5-year TVF were hemodialysis, FFR value, left main coronary artery lesion, prior percutaneous coronary intervention, and male sex. The 5-year TVF rate was 11.6% in deferred lesions, mainly driven by clinically driven target vessel revascularization. Notably, cardiac death and target vessel-related myocardial infarction rarely occurred during the follow-up. Our findings highlight the long-term safety of FFR-based deferral of revascularization in patients with chronic coronary syndrome. Registration: URL: https://www.umin.ac.jp/ctr; Unique identifier: UMIN000014473.

Differential Prognostic Implications of Pre- and Post-Stent Fractional Flow Reserve in Patients Undergoing Percutaneous Coronary Intervention.

The influence of pre-intervention coronary physiologic status on outcomes post percutaneous coronary intervention (PCI) is not well known. We sought to investigate the prognostic implications of pre-PCI fractional flow reserve (FFR) combined with post-PCI FFR. A total of 1,479 PCI patients with pre-and post-PCI FFR data were analyzed. The patients were classified according to the median values of pre-PCI FFR (0.71) and post-PCI FFR (0.88). The primary outcome was target vessel failure (TVF) at 2 years. The risk of TVF was higher in the low pre-PCI FFR group than in the high pre-PCI FFR group (hazard ratio, 1.82; 95% confidence interval, 1.15-2.87; p=0.011). In 4 group comparisons, the cumulative incidences of TVF at 2 years were 3.8%, 4.1%, 4.8%, and 10.2% in the high pre-/high post-, low pre-/high post-, high pre-/low post-, and low pre-/low post-PCI FFR groups, respectively. The risk of TVF was the highest in the low pre-/low post-PCI FFR group among the groups (p values for comparisons <0.05). In addition, the high pre-/low post-PCI FFR group presented a comparable risk of TVF with the high post-PCI FFR groups (p values for comparison >0.05). When the prognostic value of the post-PCI FFR was evaluated according to the pre-PCI FFR, the risk of TVF significantly decreased with an increase in post-PCI FFR in the low pre-PCI FFR group, but not in the high pre-PCI FFR group. Pre-PCI FFR was associated with clinical outcomes after PCI, and the prognostic value of post-PCI FFR differed according to the pre-PCI FFR. ClinicalTrials.gov Identifier: NCT04012281.