Diagnostic Performance of On-Site Automatic Coronary Computed Tomography Angiography-Derived Fractional Flow Reserve.

BACKGROUND AND OBJECTIVES: Fractional flow reserve (FFR) is an invasive standard method to identify ischemia-causing coronary artery disease (CAD). With the advancement of technology, FFR can be noninvasively computed from coronary computed tomography angiography (CCTA). Recently, a novel simpler method has been developed to calculate on-site CCTA-derived FFR (CT-FFR) with a commercially available workstation. METHODS: A total of 319 CAD patients who underwent CCTA, invasive coronary angiography, and FFR measurement were included. The primary outcome was the accuracy of CT-FFR for defining myocardial ischemia evaluated with an invasive FFR as a reference. The presence of ischemia was defined as FFR ≤0.80. Anatomical obstructive stenosis was defined as diameter stenosis on CCTA ≥50%, and the diagnostic performance of CT-FFR and CCTA stenosis for ischemia was compared. RESULTS: Among participants (mean age 64.7±9.4 years, male 77.7%), mean FFR was 0.82±0.10, and 126 (39.5%) patients had an invasive FFR value of ≤0.80. The diagnostic accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of CT-FFR were 80.6% (95% confidence interval [CI], 80.5-80.7%), 88.1% (95% CI, 82.4-93.7%), 75.6% (95% CI, 69.6-81.7%), 70.3% (95% CI, 63.1-77.4%), and 90.7% (95% CI, 86.2-95.2%), respectively. CT-FFR had higher diagnostic accuracy (80.6% vs. 59.1%, p<0.001) and discriminant ability (area under the curve from receiver operating characteristic curve 0.86 vs. 0.64, p<0.001), compared with anatomical obstructive stenosis on CCTA. CONCLUSIONS: This novel CT-FFR obtained from an on-site workstation demonstrated clinically acceptable diagnostic performance and provided better diagnostic accuracy and discriminant ability for identifying hemodynamically significant lesions than CCTA alone.

Clinical Value of Single-Projection Angiography-Derived FFR in Noninfarct-Related Artery.

BACKGROUND: The Murray law-based quantitative flow ratio (µFR) is an emerging technique that requires only 1 projection of coronary angiography with similar accuracy to quantitative flow ratio (QFR). However, it has not been validated for the evaluation of noninfarct-related artery (non-IRA) in acute myocardial infarction (AMI) settings. Therefore, our study aimed to evaluate the diagnostic accuracy of µFR and the safety of deferring non-IRA lesions with µFR >0.80 in the setting of AMI. METHODS: µFR and QFR were analyzed for non-IRA lesions of patients with AMI enrolled in the FRAME-AMI trial (Fractional Flow Reserve Versus Angiography-Guided Strategy for Management of Non-Infarction Related Artery Stenosis in Patients With Acute Myocardial Infarction), consisting of fractional flow reserve (FFR)-guided percutaneous coronary intervention and angiography-guided percutaneous coronary intervention groups. The diagnostic accuracy of µFR was compared with QFR and FFR. Patients were classified by the non-IRA µFR value of 0.80 as a cutoff value. The primary outcome was a vessel-oriented composite outcome, a composite of cardiac death, non-IRA-related myocardial infarction, and non-IRA-related repeat revascularization. RESULTS: µFR and QFR analyses were feasible in 443 patients (552 lesions). µFR showed acceptable correlation with FFR (R=0.777; P<0.001), comparable C-index with QFR to predict FFR ≤0.80 (µFR versus QFR: 0.926 versus 0.961, P=0.070), and shorter total analysis time (mean, 32.7 versus 186.9 s; P<0.001). Non-IRA with µFR >0.80 and deferred percutaneous coronary intervention had a significantly lower risk of vessel-oriented composite outcome than non-IRA with performed percutaneous coronary intervention (3.4% versus 10.5%; hazard ratio, 0.37 [95% CI, 0.14-0.99]; P=0.048). CONCLUSIONS: In patients with multivessel AMI, µFR of non-IRA showed acceptable diagnostic accuracy comparable to that of QFR to predict FFR ≤0.80. Deferred non-IRA with µFR >0.80 showed a lower risk of vessel-oriented composite outcome than revascularized non-IRA. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT02715518.

Artificial Intelligence-Enabled Quantitative Coronary Plaque and Hemodynamic Analysis for Predicting Acute Coronary Syndrome.

BACKGROUND: A lesion-level risk prediction for acute coronary syndrome (ACS) needs better characterization. OBJECTIVES: This study sought to investigate the additive value of artificial intelligence-enabled quantitative coronary plaque and hemodynamic analysis (AI-QCPHA). METHODS: Among ACS patients who underwent coronary computed tomography angiography (CTA) from 1 month to 3 years before the ACS event, culprit and nonculprit lesions on coronary CTA were adjudicated based on invasive coronary angiography. The primary endpoint was the predictability of the risk models for ACS culprit lesions. The reference model included the Coronary Artery Disease Reporting and Data System, a standardized classification for stenosis severity, and high-risk plaque, defined as lesions with ≥2 adverse plaque characteristics. The new prediction model was the reference model plus AI-QCPHA features, selected by hierarchical clustering and information gain in the derivation cohort. The model performance was assessed in the validation cohort. RESULTS: Among 351 patients (age: 65.9 ± 11.7 years) with 2,088 nonculprit and 363 culprit lesions, the median interval from coronary CTA to ACS event was 375 days (Q1-Q3: 95-645 days), and 223 patients (63.5%) presented with myocardial infarction. In the derivation cohort (n = 243), the best AI-QCPHA features were fractional flow reserve across the lesion, plaque burden, total plaque volume, low-attenuation plaque volume, and averaged percent total myocardial blood flow. The addition of AI-QCPHA features showed higher predictability than the reference model in the validation cohort (n = 108) (AUC: 0.84 vs 0.78; P < 0.001). The additive value of AI-QCPHA features was consistent across different timepoints from coronary CTA. CONCLUSIONS: AI-enabled plaque and hemodynamic quantification enhanced the predictability for ACS culprit lesions over the conventional coronary CTA analysis. (Exploring the Mechanism of Plaque Rupture in Acute Coronary Syndrome Using Coronary Computed Tomography Angiography and Computational Fluid Dynamics II [EMERALD-II]; NCT03591328).

Preventive percutaneous coronary intervention versus optimal medical therapy alone for the treatment of vulnerable atherosclerotic coronary plaques (PREVENT): a multicentre, open-label, randomised controlled trial.

BACKGROUND: Acute coronary syndrome and sudden cardiac death are often caused by rupture and thrombosis of lipid-rich atherosclerotic coronary plaques (known as vulnerable plaques), many of which are non-flow-limiting. The safety and effectiveness of focal preventive therapy with percutaneous coronary intervention of vulnerable plaques in reducing adverse cardiac events are unknown. We aimed to assess whether preventive percutaneous coronary intervention of non-flow-limiting vulnerable plaques improves clinical outcomes compared with optimal medical therapy alone. METHODS: PREVENT was a multicentre, open-label, randomised controlled trial done at 15 research hospitals in four countries (South Korea, Japan, Taiwan, and New Zealand). Patients aged 18 years or older with non-flow-limiting (fractional flow reserve >0·80) vulnerable coronary plaques identified by intracoronary imaging were randomly assigned (1:1) to either percutaneous coronary intervention plus optimal medical therapy or optimal medical therapy alone, in block sizes of 4 or 6, stratified by diabetes status and the performance of percutaneous coronary intervention in a non-study target vessel. Follow-up continued annually in all enrolled patients until the last enrolled patient reached 2 years after randomisation. The primary outcome was a composite of death from cardiac causes, target-vessel myocardial infarction, ischaemia-driven target-vessel revascularisation, or hospitalisation for unstable or progressive angina, assessed in the intention-to-treat population at 2 years. Time-to-first-event estimates were calculated with the Kaplan-Meier method and were compared with the log-rank test. This report is the principal analysis from the trial and includes all long-term analysed data. The trial is registered at ClinicalTrials.gov, NCT02316886, and is complete. FINDINGS: Between Sept 23, 2015, and Sept 29, 2021, 5627 patients were screened for eligibility, 1606 of whom were enrolled and randomly assigned to percutaneous coronary intervention (n=803) or optimal medical therapy alone (n=803). 1177 (73%) patients were men and 429 (27%) were women. 2-year follow-up for the primary outcome assessment was completed in 1556 (97%) patients (percutaneous coronary intervention group n=780; optimal medical therapy group n=776). At 2 years, the primary outcome occurred in three (0·4%) patients in the percutaneous coronary intervention group and in 27 (3·4%) patients in the medical therapy group (absolute difference -3·0 percentage points [95% CI -4·4 to -1·8]; p=0·0003). The effect of preventive percutaneous coronary intervention was directionally consistent for each component of the primary composite outcome. Serious clinical or adverse events did not differ between the percutaneous coronary intervention group and the medical therapy group: at 2 years, four (0·5%) versus ten (1·3%) patients died (absolute difference -0·8 percentage points [95% CI -1·7 to 0·2]) and nine (1·1%) versus 13 (1·7%) patients had myocardial infarction (absolute difference -0·5 percentage points [-1·7 to 0·6]). INTERPRETATION: In patients with non-flow-limiting vulnerable coronary plaques, preventive percutaneous coronary intervention reduced major adverse cardiac events arising from high-risk vulnerable plaques, compared with optimal medical therapy alone. Given that PREVENT is the first large trial to show the potential effect of the focal treatment for vulnerable plaques, these findings support consideration to expand indications for percutaneous coronary intervention to include non-flow-limiting, high-risk vulnerable plaques. FUNDING: The CardioVascular Research Foundation, Abbott, Yuhan Corp, CAH-Cordis, Philips, and Infraredx, a Nipro company.

Intravascular Imaging-Guided Optimization of Complex Percutaneous Coronary Intervention by Sex: A Subgroup Analysis of the RENOVATE-COMPLEX-PCI Trial.

Importance: There have been heterogeneous results related to sex differences in prognosis after percutaneous coronary artery intervention (PCI) for complex coronary artery lesions. Objective: To evaluate potential differences in outcomes with intravascular imaging-guided PCI of complex coronary artery lesions between women and men. Design, Setting, and Participants: This prespecified substudy evaluates the interaction of sex in the investigator-initiated, open-label, multicenter RENOVATE-COMPLEX-PCI randomized clinical trial, which demonstrated the superiority of intravascular imaging-guided PCI compared with angiography-guided PCI in patients with complex coronary artery lesions. The trial was conducted at 20 sites in Korea. Patients with complex coronary artery lesions undergoing PCI were enrolled between May 2018 and May 2021, and the median (IQR) follow-up period was 2.1 (1.4-3.0) years. Data were analyzed from December 2022 to December 2023. Interventions: After diagnostic coronary angiography, eligible patients were randomly assigned in a 2:1 ratio to receive intravascular imaging-guided PCI or angiography-guided PCI. The choice and timing of the intravascular imaging device were left to the operators' discretion. Main Outcomes and Measures: The primary end point was target vessel failure, defined as a composite of cardiac death, target vessel-related myocardial infarction, or clinically driven target vessel revascularization. Secondary end points included individual components of the primary end point. Results: Of 1639 included patients, 339 (20.7%) were women, and the mean (SD) age was 65.6 (10.2) years. There was no difference in the risk of the primary end point between women and men (9.4% vs 8.3%; adjusted hazard ratio [HR], 1.39; 95% CI, 0.89-2.18; P = .15). Intravascular imaging-guided PCI tended to have lower incidence of the primary end point than angiography-guided PCI in both women (5.2% vs 14.5%; adjusted HR, 0.34; 95% CI, 0.15-0.78; P = .01) and men (8.3% vs 11.7%; adjusted HR, 0.72; 95% CI, 0.49-1.05; P = .09) without significant interaction (P for interaction = .86). Conclusions and Relevance: In patients undergoing complex PCI, compared with angiographic guidance, intravascular imaging guidance was associated with similar reduction in the risk of target vessel failure among women and men. The treatment benefit of intravascular imaging-guided PCI showed no significant interaction between treatment strategy and sex. Trial Registration: ClinicalTrials.gov Identifier: NCT03381872.

Cost-Effectiveness of Intravascular Imaging-Guided Complex PCI: Prespecified Analysis of RENOVATE-COMPLEX-PCI Trial.

BACKGROUND: Although clinical benefits of intravascular imaging-guided percutaneous coronary intervention (PCI) in patients with complex coronary artery lesions have been observed in previous trials, the cost-effectiveness of this strategy is uncertain. METHODS: RENOVATE-COMPLEX-PCI (Randomized Controlled Trial of Intravascular Imaging Guidance vs Angiography-Guidance on Clinical Outcomes After Complex Percutaneous Coronary Intervention) was conducted in Korea between May 2018 and May 2021. This prespecified cost-effectiveness substudy was conducted using Markov model that simulated 3 states: (1) post-PCI, (2) spontaneous myocardial infarction, and (3) death. A simulated cohort was derived from the intention-to-treat population, and input parameters were extracted from either the trial data or previous publications. Cost-effectiveness was evaluated using time horizon of 3 years (within trial) and lifetime. The primary outcome was incremental cost-effectiveness ratio (ICER), an indicator of incremental cost on additional quality-adjusted life years (QALYs) gained, in intravascular imaging-guided PCI compared with angiography-guided PCI. The current analysis was performed using the Korean health care sector perspective with reporting the results in US dollar (1200 Korean Won, ₩=1 dollar, $). Willingness to pay threshold was $35 000 per QALY gained. RESULTS: A total of 1639 patients were included in the trial. During 3-year follow-up, medical costs ($8661 versus $7236; incremental cost, $1426) and QALY (2.34 versus 2.31; incremental QALY, 0.025) were both higher in intravascular imaging-guided PCI than angiography-guided PCI, resulting incremental cost-effectiveness ratio of $57 040 per QALY gained within trial data. Conversely, lifetime simulation showed total cumulative medical cost was reversed between the 2 groups ($40 455 versus $49 519; incremental cost, -$9063) with consistently higher QALY (8.24 versus 7.89; incremental QALY, 0.910) in intravascular imaging-guided PCI than angiography-guided PCI, resulting in a dominant incremental cost-effectiveness ratio. Consistently, 70% of probabilistic iterations showed cost-effectiveness of intravascular imaging-guided PCI in probabilistic sensitivity analysis. CONCLUSIONS: The current cost-effectiveness analysis suggests that imaging-guided PCI is more cost-effective than angiography-guided PCI by reducing medical cost and increasing quality-of-life in complex coronary artery lesions in long-term follow-up. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03381872.

Transradial Versus Transfemoral Access for Bifurcation Percutaneous Coronary Intervention Using Second-Generation Drug-Eluting Stent.

BACKGROUND: The benefits of transradial access (TRA) over transfemoral access (TFA) for bifurcation percutaneous coronary intervention (PCI) are uncertain because of the limited availability of device selection. This study aimed to compare the procedural differences and the in-hospital and long-term outcomes of TRA and TFA for bifurcation PCI using second-generation drug-eluting stents (DESs). METHODS: Based on data from the Coronary Bifurcation Stenting Registry III, a retrospective registry of 2,648 patients undergoing bifurcation PCI with second-generation DES from 21 centers in South Korea, patients were categorized into the TRA group (n = 1,507) or the TFA group (n = 1,141). After propensity score matching (PSM), procedural differences, in-hospital outcomes, and device-oriented composite outcomes (DOCOs; a composite of cardiac death, target vessel-related myocardial infarction, and target lesion revascularization) were compared between the two groups (772 matched patients each group). RESULTS: Despite well-balanced baseline clinical and lesion characteristics after PSM, the use of the two-stent strategy (14.2% vs. 23.7%, P = 0.001) and the incidence of in-hospital adverse outcomes, primarily driven by access site complications (2.2% vs. 4.4%, P = 0.015), were significantly lower in the TRA group than in the TFA group. At the 5-year follow-up, the incidence of DOCOs was similar between the groups (6.3% vs. 7.1%, P = 0.639). CONCLUSION: The findings suggested that TRA may be safer than TFA for bifurcation PCI using second-generation DESs. Despite differences in treatment strategy, TRA was associated with similar long-term clinical outcomes as those of TFA. Therefore, TRA might be the preferred access for bifurcation PCI using second-generation DES. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT03068494.

Differential Impact of Fractional Flow Reserve Measured After Coronary Stent Implantation by Left Ventricular Dysfunction.

Background: Both left ventricular systolic function and fractional flow reserve (FFR) are prognostic factors after percutaneous coronary intervention (PCI). However, how these prognostic factors are inter-related in risk stratification of patients after PCI remains unclarified. Objectives: This study evaluated differential prognostic implication of post-PCI FFR according to left ventricular ejection fraction (LVEF). Methods: A total of 2,965 patients with available LVEF were selected from the POST-PCI FLOW (Prognostic Implications of Physiologic Investigation After Revascularization with Stent) international registry of patients with post-PCI FFR measurement. The primary outcome was a composite of cardiac death or target-vessel myocardial infarction (TVMI) at 2 years. The secondary outcome was target-vessel revascularization (TVR) and target vessel failure, which was a composite of cardiac death, TVMI, or TVR. Results: Post-PCI FFR was independently associated with the risk of target vessel failure (per 0.01 decrease: HRadj: 1.029; 95% CI: 1.009-1.049; P = 0.005). Post-PCI FFR was associated with increased risk of cardiac death or TVMI (HRadj: 1.145; 95% CI: 1.025-1.280; P = 0.017) among patients with LVEF ≤40%, and with that of TVR in patients with LVEF >40% (HRadj: 1.028; 95% CI: 1.005-1.052; P = 0.020). Post-PCI FFR ≤0.80 was associated with increased risk of cardiac death or TVMI in the LVEF ≤40% group and with that of TVR in LVEF >40% group. Prognostic impact of post-PCI FFR for the primary outcome was significantly different according to LVEF (Pinteraction = 0.019). Conclusions: Post-PCI FFR had differential prognostic impact according to LVEF. Residual ischemia by post-PCI FFR ≤0.80 was a prognostic indicator for cardiac death or TVMI among patients with patients with LVEF ≤40%, and it was associated with TVR among patients with patients with LVEF>40%. (Prognostic Implications of Physiologic Investigation After Revascularization with Stent [POST-PCI FLOW]; NCT04684043).

Impact of sex on the assessment of the microvascular resistance reserve.

BACKGROUND: The microvascular resistance reserve (MRR) is an innovative index to assess the vasodilatory capacity of the coronary circulation while accounting for the presence of concomitant epicardial disease. The MRR has shown to be a valuable diagnostic and prognostic tool in the general coronary artery disease (CAD) population. However, considering the fundamental aspects of its assessment and the unique hemodynamic characteristics of women, it is crucial to provide additional considerations for evaluating the MRR specifically in women. AIM: The aim of this study was to assess the diagnostic and prognostic applicability of the MRR in women and assess the potential differences across different sexes. METHODS: From the ILIAS Registry, we enrolled all patients with a stable indication for invasive coronary angiography, ensuring complete physiological and follow-up data. We analyzed the diagnostic value by comparing differences between sexes and evaluated the prognostic value of the MRR specifically in women, comparing it to that in men. RESULTS: A total of 1494 patients were included of which 26% were women. The correlation between MRR and CFR was good and similar between women (r = 0.80, p < 0.005) and men (r = 0.81, p < 0.005). The MRR was an independent and important predictor of MACE in both women (HR 0.67, 0.47-0.96, p = 0.027) and men (HR 0.84, 0.74-0.95, p = 0.007). The optimal cut-off value for MRR in women was 2.8 and 3.2 in men. An abnormal MRR similarly predicted MACE at 5-year follow-up in both women and men. CONCLUSION: The MRR seems to be equally applicable in both women and men with stable coronary artery disease.

Prognostic Implications of Quantitative Flow Ratio and Plaque Characteristics in Intravascular Ultrasound-Guided Treatment Strategy.

BACKGROUND: Quantitative flow ratio (QFR) is a method for evaluating fractional flow reserve without the use of an invasive coronary pressure wire or pharmacological hyperemic agent. OBJECTIVES: The aim of this study was to investigate the prognostic implications of QFR and plaque characteristics in patients who underwent intravascular ultrasound (IVUS)-guided treatment for intermediate lesions. METHODS: Among the IVUS-guided strategy group in the FLAVOUR (Fractional Flow Reserve and Intravascular Ultrasound for Clinical Outcomes in Patients with Intermediate Stenosis) trial, vessels suitable for QFR analysis were included in this study. High-risk features were defined as low QFR (≤0.90), quantitative high-risk plaque characteristics (qn-HRPCs) (minimal lumen area ≤3.5 mm2, or plaque burden ≥70%), and qualitative high-risk plaque characteristics (ql-HRPCs) (attenuated plaque, positive remodeling, or plaque rupture) assessed using IVUS. The primary clinical endpoint was target vessel failure (TVF), defined as a composite of cardiac death, target vessel myocardial infarction, and target vessel revascularization. RESULTS: A total of 415 (46.1%) vessels could be analyzable for QFR. The numbers of qn-HRPCs and ql-HRPCs increased with decreasing QFR. Among deferred vessels, those with 3 high-risk features exhibits a significantly higher risk of TVF compared with those with ≤2 high-risk features (12.0% vs 2.7%; HR: 4.54; 95% CI: 1.02-20.29). CONCLUSIONS: Among the IVUS-guided deferred group, vessels with qn-HRPC and ql-HRPC with low QFR (≤0.90) exhibited a significantly higher risk for TVF compared with those with ≤2 features. Integrative assessment of angiography-derived fractional flow reserve and anatomical and morphological plaque characteristics is recommended to improve clinical outcomes in patients undergoing IVUS-guided deferred treatment.

Relationship of Coronary Angiography-Derived Radial Wall Strain With Functional Significance, Plaque Morphology, and Clinical Outcomes.

BACKGROUND: Coronary angiography-derived radial wall strain (RWS) is a newly developed index that can be readily accessed and describes the biomechanical features of a lesion. OBJECTIVES: The authors sought to investigate the association of RWS with fractional flow reserve (FFR) and high-risk plaque (HRP), and their relative prognostic implications. METHODS: We included 484 vessels (351 patients) deferred after FFR measurement with available RWS data and coronary computed tomography angiography. On coronary computed tomography angiography, HRP was defined as a lesion with both minimum lumen area <4 mm2 and plaque burden ≥70%. The primary outcome was target vessel failure (TVF), a composite of target vessel revascularization, target vessel myocardial infarction, or cardiac death. RESULTS: The mean FFR and RWSmax were 0.89 ± 0.07 and 11.2% ± 2.5%, respectively, whereas 27.7% of lesions had HRP, 15.1% had FFR ≤0.80. An increase in RWSmax was associated with a higher risk of FFR ≤0.80 and HRP, which was consistent after adjustment for clinical or angiographic characteristics (all P < 0.05). An increment of RWSmax was related to a higher risk of TVF (HR: 1.23 [95% CI: 1.03-1.47]; P = 0.022) with an optimal cutoff of 14.25%. RWSmax >14% was a predictor of TVF after adjustment for FFR or HRP components (all P < 0.05) and showed a direct prognostic effect on TVF, not mediated by FFR ≤0.80 or HRP in the mediation analysis. When high RWSmax was added to FFR ≤0.80 or HRP, there were increasing outcome trends (all P for trend <0.001). CONCLUSIONS: RWS was associated with coronary physiology and plaque morphology but showed independent prognostic significance.

Physiology- or Imaging-Guided Strategies for Intermediate Coronary Stenosis.

Importance: 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. Objectives: To investigate outcomes according to treatment types and FFR and IVUS parameters after FFR- or IVUS-guided treatment. Design, Setting, and Participants: 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. Exposures: FFR or IVUS parameters within the deferred and revascularized vessels. Main Outcomes and Measures: The primary outcome was target vessel failure (TVF), a composite of cardiac death, target vessel myocardial infarction, and revascularization at 2 years. Results: 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). Conclusions and Relevance: 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.

Intravascular Imaging-Guided Percutaneous Coronary Intervention Before and After Standardized Optimization Protocols.

BACKGROUND: Although benefits of intravascular imaging (IVI) in percutaneous coronary intervention (PCI) have been observed in previous studies, it is not known whether changes in contemporary practice, especially with application of standardized optimization protocols, have improved clinical outcomes. OBJECTIVES: The authors sought to investigate whether clinical outcomes of IVI-guided PCI are different before and after the application of standardized optimization protocols in using IVI. METHODS: 2,972 patients from an institutional registry (2008-2015, before application of standardized optimization protocols, the past group) and 1,639 patients from a recently published trial (2018-2021 after application of standardized optimization protocols, the present group) were divided into 2 groups according to use of IVI. The primary outcome was 3-year target vessel failure (TVF), a composite of cardiac death, target vessel myocardial infarction, or target vessel revascularization. RESULTS: Significant reduction of TVF was observed in the IVI-guided PCI group compared with the angiography-guided PCI group (10.0% vs 6.7%; HR: 0.77; 95% CI: 0.61-0.97; P = 0.027), mainly driven by reduced cardiac death or myocardial infarction in both past and present IVI-guided PCI groups. When comparing past IVI and present IVI groups, TVF was significantly lower in the present IVI group (8.5% vs 5.1%; HR: 0.63; 95% CI: 0.42-0.94; P = 0.025), with the difference being driven by reduced target vessel revascularization in the present IVI group. Consistent results were observed in inverse-probability-weighting adjusted analysis. CONCLUSIONS: IVI-guided PCI improved clinical outcomes more than angiography-guided PCI. In addition, application of standardized optimization protocols when using IVI further improved clinical outcomes after PCI. (Intravascular Imaging- Versus Angiography-Guided Percutaneous Coronary Intervention For Complex Coronary Artery Disease [RENOVATE-COMPLEX-PCI]; NCT03381872; and the institutional cardiovascular catheterization database of Samsung Medical Center: Long-Term Outcomes and Prognostic Factors in Patient Undergoing CABG or PCI; NCT03870815).

Cost-Effectiveness of Fractional Flow Reserve-Guided Treatment for Acute Myocardial Infarction and Multivessel Disease: A Prespecified Analysis of the FRAME-AMI Randomized Clinical Trial.

Importance: Complete revascularization by non-infarct-related artery (IRA) percutaneous coronary intervention (PCI) in patients with acute myocardial infarction is standard practice to improve patient prognosis. However, it is unclear whether a fractional flow reserve (FFR)-guided or angiography-guided treatment strategy for non-IRA PCI would be more cost-effective. Objective: To evaluate the cost-effectiveness of FFR-guided compared with angiography-guided PCI in patients with acute myocardial infarction and multivessel disease. Design, Setting, and Participants: In this prespecified cost-effectiveness analysis of the FRAME-AMI randomized clinical trial, patients were randomly allocated to either FFR-guided or angiography-guided PCI for non-IRA lesions between August 19, 2016, and December 24, 2020. Patients were aged 19 years or older, had ST-segment elevation myocardial infarction (STEMI) or non-STEMI and underwent successful primary or urgent PCI, and had at least 1 non-IRA lesion (diameter stenosis >50% in a major epicardial coronary artery or major side branch with a vessel diameter of ≥2.0 mm). Data analysis was performed on August 27, 2023. Intervention: Fractional flow reserve-guided vs angiography-guided PCI for non-IRA lesions. Main Outcomes and Measures: The model simulated death, myocardial infarction, and repeat revascularization. Future medical costs and benefits were discounted by 4.5% per year. The main outcomes were quality-adjusted life-years (QALYs), direct medical costs, incremental cost-effectiveness ratio (ICER), and incremental net monetary benefit (INB) of FFR-guided PCI compared with angiography-guided PCI. State-transition Markov models were applied to the Korean, US, and European health care systems using medical cost (presented in US dollars), utilities data, and transition probabilities from meta-analysis of previous trials. Results: The FRAME-AMI trial randomized 562 patients, with a mean (SD) age of 63.3 (11.4) years. Most patients were men (474 [84.3%]). Fractional flow reserve-guided PCI increased QALYs by 0.06 compared with angiography-guided PCI. The total cumulative cost per patient was estimated as $1208 less for FFR-guided compared with angiography-guided PCI. The ICER was -$19 484 and the INB was $3378, indicating that FFR-guided PCI was more cost-effective for patients with acute myocardial infarction and multivessel disease. Probabilistic sensitivity analysis showed consistent results and the likelihood iteration of cost-effectiveness in FFR-guided PCI was 97%. When transition probabilities from the pairwise meta-analysis of the FLOWER-MI and FRAME-AMI trials were used, FFR-guided PCI was more cost-effective than angiography-guided PCI in the Korean, US, and European health care systems, with an INB of $3910, $8557, and $2210, respectively. In probabilistic sensitivity analysis, the likelihood iteration of cost-effectiveness with FFR-guided PCI was 85%, 82%, and 31% for the Korean, US, and European health care systems, respectively. Conclusions and Relevance: This cost-effectiveness analysis suggests that FFR-guided PCI for non-IRA lesions saved medical costs and increased quality of life better than angiography-guided PCI for patients with acute myocardial infarction and multivessel disease. Fractional flow reserve-guided PCI should be considered in determining the treatment strategy for non-IRA stenoses in these patients. Trial Registration: ClinicalTrials.gov Identifier: NCT02715518.

Angiographic Severity of the Nonculprit Lesion and the Efficacy of Fractional Flow Reserve-Guided Complete Revascularization in Patients With AMI: FRAME-AMI Substudy.

BACKGROUND: The benefit of fractional flow reserve (FFR)-guided percutaneous coronary intervention (PCI) for noninfarct-related artery (IRA) lesions with angiographically severe stenosis in patients with acute myocardial infarction is unclear. METHODS: Among 562 patients from the FRAME-AMI trial (Fractional Flow Reserve Versus Angiography-Guided Strategy for Management of Non-Infraction Related Artery Stenosis in Patients With Acute Myocardial Infarction) who were randomly allocated into either FFR-guided or angiography-guided PCI for non-IRA lesions, the current study evaluated the relationship between non-IRA stenosis measured by quantitative coronary angiography (QCA) and the efficacy of FFR-guided PCI. The incidence of the primary end point (death, myocardial infarction, or repeat revascularization) was compared between FFR- and angiography-guided PCI according to non-IRA stenosis severity (QCA stenosis ≥70% or <70%). RESULTS: A total of 562 patients were assigned to FFR-guided (n=284) versus angiography-guided PCI (n=278). At a median follow-up of 3.5 years, the primary end point occurred in 14 of 181 patients with FFR-guided PCI and 31 of 197 patients with angiography-guided PCI among patients with QCA stenosis ≥70% (8.5% versus 19.2%; hazard ratio, 0.41 [95% CI, 0.22-0.80]; P=0.008), while occurred in 4 of 103 patients with FFR-guided PCI and 9 of 81 patients with angiography-guided PCI among those with QCA stenosis <70% (3.9% versus 11.1%; P=0.315). There was no significant interaction between treatment strategy and non-IRA stenosis severity (P for interaction=0.636). FFR-guided PCI was associated with the reduction of death and myocardial infarction in both patients with QCA stenosis ≥70% (6.7% versus 15.1%; P=0.008) and those with QCA stenosis <70% (1.0% versus 9.6%; P=0.042) compared with angiography-guided PCI. CONCLUSIONS: In patients with acute myocardial infarction and multivessel disease, FFR-guided PCI tended to have a lower risk of primary end point than angiography-guided PCI regardless of non-IRA stenosis severity without significant interaction. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT02715518.

Practical Application of Coronary Physiologic Assessment: Asia-Pacific Expert Consensus Document: Part 1.

Coronary physiologic assessment is performed to measure coronary pressure, flow, and resistance or their surrogates to enable the selection of appropriate management strategy and its optimization for patients with coronary artery disease. The value of physiologic assessment is supported by a large body of evidence that has led to major recommendations in clinical practice guidelines. This expert consensus document aims to convey practical and balanced recommendations and future perspectives for coronary physiologic assessment for physicians and patients in the Asia-Pacific region based on updated information in the field that including both wire- and image-based physiologic assessment. This is Part 1 of the whole consensus document, which describes the general concept of coronary physiology, as well as practical information on the clinical application of physiologic indices and novel image-based physiologic assessment.

Practical Application of Coronary Physiologic Assessment: Asia-Pacific Expert Consensus Document: Part 2.

Coronary physiologic assessment is performed to measure coronary pressure, flow, and resistance or their surrogates to enable the selection of appropriate management strategy and its optimization for patients with coronary artery disease. The value of physiologic assessment is supported by a large body of clinical data that has led to major recommendations in all practice guidelines. This expert consensus document aims to convey practical and balanced recommendations and future perspectives for coronary physiologic assessment for physicians and patients in the Asia-Pacific region, based on updated information in the field that includes both wire- and image-based physiologic assessment. This is Part 2 of the whole consensus document, which provides theoretical and practical information on physiologic indexes for specific clinical conditions and patient statuses.

Prognostic Implications of Individual and Combinations of Resting and Hyperemic Coronary Pressure and Flow Parameters.

Background: Coronary pressure- and flow-derived parameters have prognostic value. Objectives: This study aims to investigate the individual and combined prognostic relevance of pressure and flow parameters reflecting resting and hyperemic conditions. Methods: A total of 1,971 vessels deferred from revascularization after invasive pressure and flow assessment were included from the international multicenter registry. Abnormal resting pressure and flow were defined as distal coronary pressure/aortic pressure ≤0.92 and high resting flow (1/resting mean transit time >2.4 or resting average peak flow >22.7 cm/s), and abnormal hyperemic pressure and flow as fractional flow reserve ≤0.80 and low hyperemic flow (1/hyperemic mean transit time <2.2 or hyperemic average peak flow <25.0 cm/s), respectively. The clinical endpoint was target vessel failure (TVF), myocardial infarction (MI), or cardiac death at 5 years. Results: The mean % diameter stenosis was 46.8% ± 16.5%. Abnormal pressure and flow were independent predictors of TVF and cardiac death/MI (all P < 0.05). The risk of 5-year TVF or MI/cardiac death increased proportionally with neither, either, and both abnormal resting pressure and flow, and abnormal hyperemic pressure and flow (all P for trend < 0.001). Abnormal resting pressure and flow were associated with a higher rate of TVF or MI/cardiac death in vessels with normal fractional flow reserve; this association was similar for abnormal hyperemic pressure and flow in vessels with normal resting distal coronary pressure/aortic pressure (all P < 0.05). Conclusions: Abnormal resting and hyperemic pressure and flow were independent prognostic predictors. The abnormal flow had an additive prognostic value for pressure in both resting and hyperemic conditions with complementary prognostic between resting and hyperemic parameters.