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.

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.

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.

Intravascular imaging-guided percutaneous coronary intervention in patients with acute myocardial infarction and cardiogenic shock

INTRODUCTION AND OBJECTIVES

There are no clinical data on the efficacy of intravascular imaging-guided percutaneous coronary intervention (PCI) compared with angiography-guided PCI in patients with acute myocardial infarction (AMI) and cardiogenic shock. The current study sought to evaluate the impact of intravascular imaging-guided PCI in patients with AMI and cardiogenic shock.

METHODS

Among a total of 28 732 patients from the nationwide pooled registry of KAMIR-NIH (November, 2011 to December, 2015) and KAMIR-V (January, 2016 to June, 2020), we selected a total of 1833 patients (6.4%) with AMI and cardiogenic shock who underwent PCI of the culprit vessel. The primary endpoint was major adverse cardiovascular events (MACE) at 1 year, a composite of cardiac death, myocardial infarction, repeat revascularization, and definite or probable stent thrombosis.

RESULTS

Among the study population, 375 patients (20.5%) underwent intravascular imaging-guided PCI and 1458 patients (79.5%) underwent angiography-guided PCI. Intravascular imaging-guided PCI was associated with a significantly lower risk of 1-year MACE than angiography-guided PCI (19.5% vs 28.2%; HR, 0.59; 95%CI, 0.45-0.77; P<.001), mainly driven by a lower risk of cardiac death (13.7% vs 24.0%; adjusted HR, 0.53; 95%CI, 0.39-0.72; P<.001). These results were consistent in propensity score matching (HR, 0.68; 95%CI, 0.46-0.99), inverse probability weighting (HR, 0.61; 95%CI, 0.45-0.83), and Bayesian analysis (Odds ratio, 0.66, 95% credible interval, 0.49-0.88).

CONCLUSIONS

In AMI patients with cardiogenic shock, intravascular imaging-guided PCI was associated with a lower risk of MACE at 1-year than angiography-guided PCI, mainly driven by the lower risk of cardiac death.

Association between intensive care unit nursing grade and mortality in patients with cardiogenic shock and its cost-effectiveness

BACKGROUND

Despite the high workload of cardiac intensive care unit (ICU), there is a paucity of evidence on the association between nurse workforce and mortality in patients with cardiogenic shock (CS). This study aimed to evaluate the prognostic impact of the ICU nursing grade on mortality and cost-effectiveness in CS.

METHODS

A nationwide analysis was performed using the K-NHIS database. Patients diagnosed with CS and admitted to the ICU at tertiary hospitals were enrolled. ICU nursing grade was defined according to the bed-to-nurse ratio: grade1 (bed-to-nurse ratio < 0.5), grade2 (0.5 ≤ bed-to-nurse ratio < 0.63), and grade3 (0.63 ≤ bed-to-nurse ratio < 0.77) or above. The primary endpoint was in-hospital mortality. Cost-effective analysis was also performed.

RESULTS

Of the 72,950 patients with CS, 27,216 (37.3%) were in ICU nursing grade 1, 29,710 (40.7%) in grade 2, and 16,024 (22.0%) in grade ≥ 3. The adjusted-OR for in-hospital mortality was significantly higher in patients with grade 2 (grade 1 vs. grade 2, 30.6% vs. 37.5%, adjusted-OR 1.14, 95% CI1.09-1.19) and grade ≥ 3 (40.6%) with an adjusted-OR of 1.29 (95% CI 1.23-1.36) than those with grade 1. The incremental cost-effectiveness ratio of grade1 compared with grade 2 and ≥ 3 was $25,047/year and $42,888/year for hospitalization and $5151/year and $5269/year for 1-year follow-up, suggesting that grade 1 was cost-effective. In subgroup analysis, the beneficial effects of the high-intensity nursing grade on mortality were more prominent in patients who received CPR or multiple vasopressors usage.

CONCLUSIONS

For patients with CS, ICU grade 1 with a high-intensity nursing staff was associated with reduced mortality and more cost-effectiveness during hospitalization compared to grade 2 and grade ≥ 3, and its beneficial effects were more pronounced in subjects at high risk of CS.

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.

Digital coincidence counting with 4πβ(PPC)-γ for the standardization of 60Co

A 4πβ(PPC)-γ coincidence system has been made at KRISS based on a digital DAQ. 60Co sources were measured to verify the system. The maximum detection efficiency for beta particles was estimated to be 96.7 %. Massic activities for sample sources had 0.005 % of the sample variability error, which was well within the expanded standard uncertainty of 0.54 % (k = 2).

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).

Physiologic Assessment After Percutaneous Coronary Interventions and Functionally Optimized Revascularization

Coronary physiologic assessment has become a standard of care for patients with coronary atherosclerotic disease. While most attention has focused on pre-interventional physiologic assessment to aid in revascularization decision-making, post-interventional physiologic assessment has not been as widely used, despite evidence supporting its role in assessment and optimization of the revascularization procedure. A thorough understanding of such evidence and ongoing studies would be crucial to incorporate post-interventional physiologic assessment into daily practice. Thus, this review provides a comprehensive overview of current evidence regarding the evolving role of physiologic assessment as a functional optimization tool for the entire revascularization process.

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.

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.

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.

Changes in microvascular resistance following percutaneous coronary intervention - From the ILIAS global registry

BACKGROUND

Microvascular resistance (MR) has prognostic value in acute and chronic coronary syndromes following percutaneous coronary intervention (PCI), however anatomic and physiologic determinants of the relative changes of MR and its association to target vessel failure (TVF) has not been investigated previously. This study aims to evaluate the association between changes in MR and TVF.

METHODS

This is a sub-study of the Inclusive Invasive Physiological Assessment in Angina Syndromes (ILIAS) registry which is a global multi-centre initiative pooling lesion-level coronary pressure and flow data.

RESULTS

Paired pre-post PCI haemodynamic data were available in n = 295 vessels out of n = 828 PCI treated patients and of these paired data on MR was present in n = 155 vessels. Vessels were divided according to increase vs. decrease % in microvascular resistance following PCI (ΔMR % ≤ 0 vs. ΔMR > 0%). Decreased microvascular resistance ΔMR % ≤ 0 occurred in vessels with lower pre-PCI fractional flow reserve (0.67 ± 0.15 vs. 0.72 ± 0.09 p = 0.051), coronary flow reserve (1.9 ± 0.8 vs. 2.6 ± 1.8 p < 0.0001) and higher hyperemic microvascular resistance (2.76 ± 1.3 vs. 1.62 ± 0.74 p = 0.001) and index of microvascular resistance (24.4 IQ (13.8) vs. 15. 8 IQ (13.2) p = 0.004). There was no difference in angiographic parameters between ΔMR % ≤ 0 vs. ΔMR > 0%. In a cox regression model ΔMR % > 0 was associated with increased rate of TVF (hazard ratio 95% CI 3.6 [1.2; 10.3] p = 0.018).

CONCLUSION

Increased MR post-PCI was associated with lesions of less severe hemodynamic influence at baseline and higher rates of TVF at follow-up.

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

BACKGROUND

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.

METHODS

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.

RESULTS

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).

CONCLUSIONS

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.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT02673424.

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.

Clinical Benefit of Intravascular Imaging Compared With Conventional Angiography in Left Main Coronary Artery Intervention

BACKGROUND

The RENOVATE-COMPLEX-PCI (Randomized Controlled Trial of Intravascular Imaging Guidance Versus Angiography-Guidance on Clinical Outcomes After Complex Percutaneous Coronary Intervention) demonstrated that intravascular imaging-guided percutaneous coronary intervention (PCI) improved clinical outcome compared with angiography-guided PCI for patients with complex coronary artery lesions. This study aims to assess whether the prognostic benefit of intravascular imaging-guided procedural optimization persists in patients undergoing PCI for left main coronary artery disease.

METHODS

Of 1639 patients enrolled in the RENOVATE-COMPLEX-PCI, 192 patients with left main coronary artery disease were selected for the current prespecified substudy. Selected patients were randomly assigned to either the intravascular imaging-guided PCI group (n=138) or the angiography-guided PCI group (n=54). 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.

RESULTS

At a median follow-up of 2.1 years (interquartile range 1.1 to 3.0 years), intravascular imaging-guided PCI was associated with lower incidence of primary end point compared with angiography-guided PCI (6.8% versus 25.1%; hazard ratio, 0.31 [95% CI, 0.13-0.76]; P=0.010). This significant reduction in primary end point was mainly driven by a lower risk of cardiac death or spontaneous target vessel-related myocardial infarction (1.6% versus 12.7%; hazard ratio, 0.16 [95% CI, 0.03-0.82]; P=0.028). Intravascular imaging-guided PCI was independently associated with a lower risk of primary end point, even after adjusting for various clinical factors (hazard ratio, 0.29 [95% CI, 0.12-0.72]; P=0.007).

CONCLUSIONS

Intravascular imaging-guided PCI showed clinical benefit over angiography-guided PCI for left main coronary artery disease in reducing the risk of cardiac death, target vessel-related myocardial infarction, or target vessel revascularization.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT03381872.

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.

Sex-Based Outcomes of P2Y12 Inhibitor Monotherapy After Three Months of Dual Antiplatelet Therapy in Patients Undergoing Percutaneous Coronary Intervention

BACKGROUND

In patients undergoing percutaneous coronary intervention (PCI) in the SMART-CHOICE trial, P2Y12 inhibitor monotherapy after three months of dual antiplatelet therapy (DAPT) achieved clinical outcomes comparable to those of 12 months of DAPT. Nonetheless, the effects of sex on these outcomes remain unknown.

METHODS

This open-label, non-inferiority, randomized study, conducted in 33 hospitals in South Korea, included 2,993 patients undergoing PCI with drug-eluting stents. Patients were randomly assigned to receive DAPT (aspirin plus a P2Y12 inhibitor) for three months then P2Y12 inhibitor alone for nine months, or DAPT for the entire 12 months. The primary endpoints were major adverse cardiac and cerebrovascular events (a composite of all-cause death, myocardial infarction, or stroke) 12 months after the index procedure. The bleeding endpoints were Bleeding Academic Research Consortium (BARC) bleeding types 2 to 5.

RESULTS

Of the patients, 795 (26.6%) were women, who were older and had a higher prevalence of hypertension, diabetes, and dyslipidemia than men. The sexes exhibited comparable primary endpoints (adjusted hazard ratio [HR], 0.93; 95% confidence interval [CI], 0.55-1.55; P = 0.770) and bleeding endpoints (adjusted HR, 1.07; 95% CI, 0.63-1.81; P = 0.811). P2Y12 inhibitor monotherapy vs DAPT was associated with lower risk of BARC type 2 to 5 bleeding in women (adjusted HR, 0.40; 95% CI, 0.16-0.98; P = 0.045) but the difference was not statistically significant when using the Bonferroni correction. The primary endpoints were similar between treatment groups in both sexes.

CONCLUSION

In both sexes undergoing PCI, P2Y12 inhibitor monotherapy after three months of DAPT achieved similar risks of the primary endpoints and the bleeding events compared with prolonged DAPT. Therefore, the benefits of early aspirin withdrawal with ongoing P2Y12 inhibitors may be comparable in women and men.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02079194.

Sex differences in prevalence and outcomes of the different endotypes of chronic coronary syndrome in symptomatic patients undergoing invasive coronary angiography: Insights from the global ILIAS invasive coronary physiology registry

BACKGROUND AND AIMS

The management of chronic coronary syndrome (CCS) is informed by studies predominantly including men. This study investigated the relationship between patients sex and different endotypes of CCS, including sex-specific clinical outcomes.

METHODS

In patients with CCS undergoing coronary angiography, invasive Fractional Flow Reserve (FFR) and Coronary Flow Reserve (CFR) were measured. Patients were stratified into groups: 1) obstructive coronary artery disease (oCAD) (FFR≤0.80, no revascularization), 2) undergoing revascularization, 3) non-obstructive coronary artery disease with coronary microvascular dysfunction (CMD) (FFR>0.80, CFR≤2.5), and 4) non-obstructive coronary artery disease without CMD (FFR>0.80 and CFR>2.5).

RESULTS

1836 patients (2335 vessels) were included, comprising 1359 (74.0%) men and 477 (26.0%) women. oCAD was present in 14.1% and was significantly less prevalent in women than in men (10.3% vs 15.5%, respectively p < 0.01). Revascularization was present in 30.9% and was similarly prevalent in women and men (28.2% vs. 31.9%, respectively p = 0.13). CMD was present in 24.2% and was significantly more prevalent in women than men (28.6% vs 22.6%, respectively p < 0.01). Normal invasive measurements were found in 564 patients (33.0% women vs 30.0% men, p = 0.23). Male sex was associated with an increased risk of target vessel failure compared to women (HR.1.89, 95% CI 1.12-3.18, p = 0.018), regardless of CCS-endotype.

CONCLUSIONS

Sex differences exist in the prevalence and outcomes of different endotypes of CCS in symptomatic patients undergoing invasive coronary angiography. In particular, oCAD (and subsequent revascularization) were more prevalent in men. Conversely, CMD was more prevalent in women. Overall, men experienced a worse cardiovascular outcome compared to women, independent of any specific CCS endotype.

Intravascular Imaging in Patients With Complex Coronary Lesions and Chronic Kidney Disease

Importance

As patients with chronic kidney disease (CKD) are more likely to have complex coronary lesions, intravascular imaging guidance in percutaneous coronary intervention (PCI) for this population could be potentially beneficial.

Objectives

To investigate whether the outcomes of intravascular imaging-guided procedural optimization would be different according to the presence of CKD.

Design, Setting, and Participants

This was a prespecified substudy of RENOVATE-COMPLEX-PCI, a recently published multicenter randomized clinical trial in Korea studying the benefits of intravascular imaging for complex coronary lesions. Patients with complex coronary lesions, with or without CKD, were enrolled between May 2018 and May 2021. Data were analyzed from January to June 2023.

Interventions

PCI in each group was done either under the guidance of intravascular imaging or angiography alone.

Main Outcomes and Measures

The primary end point was target vessel failure (TVF) at the 3-year point, defined as a composite of cardiac death, target vessel-related myocardial infarction, or clinically driven target vessel revascularization.

Results

A total of 1639 patients (1300 male [79.3%]) treated with PCI for complex coronary lesions were stratified into CKD (296 participants) and non-CKD (1343 participants) groups. The mean (SD) age of each group was 70.3 (9.4) and 64.5 (10.1) years, and mean (SD) estimated serum creatinine was 2.9 (5.3) and 0.8 (0.2) mg/dL for CKD and non-CKD groups, respectively. Intravascular imaging-guided revascularization was associated with significantly lower incidence of the primary end point compared with angiography-guided revascularization in both CKD (13.3% vs 23.3%; hazard ratio [HR], 0.51; 95% CI, 0.27-0.93; P = .03) and non-CKD (6.4% vs 9.9%; HR, 0.66; 95% CI, 0.44-0.99; P = .05) groups. The significantly lower incidence of the primary end point was mainly associated with the lower risk of cardiac death or target vessel-related myocardial infarction (9.4% vs 22.2%; HR, 0.39; 95% CI, 0.20-0.76; P = .006) in the CKD group and by target vessel revascularization (3.0% vs 5.5%; HR, 0.55; 95% CI, 0.30-0.99; P = .05) in the non-CKD group. Those with a glomerular filtration rate of at least 30 mL/min/1.73m2 and less than 60 ml/kg/1.73m2 showed the greatest benefit from imaging-guided complex PCI (8.8% vs 21.2%; HR, 0.28; 95% CI, 0.11-0.68; P = .02).

Conclusions and Relevance

In this prespecified cohort substudy of the Randomized Controlled Trial of Intravascular Imaging Guidance versus Angiography-Guidance on Clinical Outcomes After Complex Percutaneous Coronary Intervention trial, intravascular imaging guidance showed clinical benefit over angiography guidance in reducing the risk of TVF, regardless of the presence of CKD. The greatest benefits of imaging-guided complex PCI were observed in stage 3 CKD.

Trial Registration

ClinicalTrials.gov Identifier: NCT03381872.

QFR Assessment and Prognosis After Nonculprit PCI in Patients With Acute Myocardial Infarction

BACKGROUND

Complete revascularization using either angiography-guided or fractional flow reserve (FFR)-guided strategy can improve clinical outcomes in patients with acute myocardial infarction (AMI) and multivessel disease. However, there is concern that angiography-guided percutaneous coronary intervention (PCI) may result in un-necessary PCI of the non-infarct-related artery (non-IRA), and its long-term prognosis is still unclear.

OBJECTIVES

This study sought to evaluate clinical outcomes after non-IRA PCI according to the quantitative flow ratio (QFR).

METHODS

We performed post hoc QFR analysis of non-IRA lesions of AMI patients enrolled in the FRAME-AMI (FFR Versus Angiography-Guided Strategy for Management of AMI With Multivessel Disease) trial, which randomly allocated 562 patients into either FFR-guided PCI (FFR ≤0.80) or angiography-guided PCI (diameter stenosis >50%) for non-IRA lesions. Patients were classified by non-IRA QFR values into the QFR ≤0.80 and QFR >0.80 groups. The primary outcome was a major adverse cardiac event (MACE), a composite of cardiac death, myocardial infarction, and repeat revascularization.

RESULTS

A total of 443 patients (552 lesions) were eligible for QFR analysis. Of 209 patients in the angiography-guided PCI group, 30.0% (n = 60) underwent non-IRA PCI despite having QFR >0.80 in the non-IRA. Conversely, only 2.7% (n = 4) among 209 patients in the FFR-guided PCI group had QFR >0.80 in the non-IRA. At a median follow-up of 3.5 years, the rate of MACEs was significantly higher among patients with non-IRA PCI despite QFR >0.80 than in patients with deferred PCI for non-IRA lesions (12.9% vs 3.1%; HR: 4.13; 95% CI: 1.10-15.57; P = 0.036). Non-IRA PCI despite QFR >0.80 was associated with a higher risk of non-IRA MACEs than patients with deferred PCI for non-IRA lesions (12.9% vs 2.1%; HR: 5.44; 95% CI: 1.13-26.19; P = 0.035).

CONCLUSIONS

In AMI patients with multivessel disease, 30.0% of angiography-guided PCI resulted in un-necessary PCI for the non-IRA with QFR >0.80, which was significantly associated with an increased risk of MACEs than in those with deferred PCI for non-IRA lesions. (FFR Versus Angiography-Guided Strategy for Management of AMI With Multivessel Disease [FRAME-AMI] ClinicalTrials.gov number; NCT02715518).

Sex Differences in Fractional Flow Reserve- or Intravascular Ultrasound-Guided Percutaneous Coronary Intervention

BACKGROUND

A recent randomized trial reported fractional flow reserve (FFR)-guided percutaneous coronary intervention (PCI) strategy was noninferior to the intracoronary ultrasound (IVUS)-guided PCI strategy with respect to clinical outcomes with fewer revascularizations.

OBJECTIVES

This study sought to investigate the sex differences in treatment and clinical outcomes according to physiology- or imaging-guided PCI strategies.

METHODS

In this secondary analysis of the FLAVOUR (Fractional Flow Reserve or Intravascular Ultrasonography to Guide PCI) trial, the impact of sex on procedural characteristics, PCI rate, and outcomes according to different strategies and treatment types (PCI vs deferral of PCI) was analyzed. The primary outcome was target vessel failure (TVF) at 24 months, defined as a composite of cardiac death, target vessel myocardial infarction, and target vessel revascularization.

RESULTS

Of 1,619 patients, 30% were women. Compared with men, women had a smaller minimal lumen area, smaller plaque burden, and higher FFR. They had a lower PCI rate (40.8% vs 47.9%; P = 0.008), which was mainly contributed by FFR guidance. Overall, women showed a lower TVF rate (2.4% vs 4.5%). According to the treatment type, the cumulative incidence of TVF was lower in women than in men among those with the deferral of PCI (1.7% vs 5.2%). However, this trend was not observed in patients who underwent PCI. In both women and men, there were no differences in clinical outcomes between the FFR- and IVUS-guided strategies.

CONCLUSIONS

In cases of intermediate stenosis, despite receiving fewer interventions, women had more favorable outcomes than men. The use of FFR led to a lower PCI rate but had a similar prognostic value compared with IVUS in both women and men.