Fractional flow reserve versus angiography for guidance of PCI in patients with multivessel coronary artery disease (FAME): 5-year follow-up of a randomised controlled trial

Diagnostic performance of quantitative flow ratio versus fractional flow reserve and resting full-cycle ratio in intermediate coronary lesions

BACKGROUND

Quantitative flow ratio (QFR) is a novel angiography-derived index aimed to assess the functional relevance of coronary stenoses without pressure wires and adenosine. Good diagnostic yield with the hyperemic fractional flow reserve (FFR) have been reported, while data on the comparison of QFR to non-hyperemic pressure ratios (NHPR) are scarce.

METHODS

In this retrospective, observational and single-center study with a large population representative of the real practice, we assessed and compared the diagnostic performance of contrast flow (cQFR) and fixed flow (fQFR) QFR against the NHPR resting full-cyle ratio (RFR) using FFR as reference standard.

RESULTS

A total of 626 lesions from 544 patients were investigated. Mean diameter stenosis, FFR, cQFR, fQFR and RFR were 44.8%, 0.842, 0.847, 0.857 and 0.912, respectively. The correlation between cQFR and FFR was stronger (r = 0.830, P < 0.001) compared to that between FFR and RFR (r = 0.777, P < 0.001) and between cQFR and RFR (r = 0.687, P < 0.001). Using FFR ≤0.80 as reference, the sensitivity, specificity, positive predictive value, negative predictive value, and overall diagnostic accuracy for cQFR were 82%, 95%, 87%, 92%, and 91%, respectively. cQFR displayed a higher area under the curve (AUC) than fQFR and RFR (0.938 vs. 0.891 vs. 0.869, P < 0.01). The good diagnostic yield of cQFR appeared to be maintained in different clinical subsets including female gender, aortic valve stenosis and atrial fibrillation, and in different anatomical subsets including focal and non-focal lesions.

CONCLUSION

cQFR has a high and better diagnostic performance than the NHPR RFR in predicting FFR-based functional significance of coronary stenoses.

Assessment of left main coronary artery disease: a comparison between invasive and noninvasive

Left main coronary artery disease has significant therapeutic as well as prognostic implications. The presence of left main coronary artery stenosis is strongly associated with poor short- and long-term prognoses. Accurate identification of left main stenosis is extremely important since it would be the main factor to guide management. There are several modalities used to determine the presence of atherosclerosis and the degree of stenosis in a left main coronary artery. Newer modalities allow for an accurate evaluation of left main stenosis and atherosclerosis. In this review, we go through different invasive and noninvasive modalities to diagnose left main stenosis, shedding more light into coronary computed tomography angiography, and its accuracy in this specific diagnosis.

Coronary functional assessment in non-obstructive coronary artery disease: Present situation and future direction

Non-obstructive coronary artery disease (CAD), which is defined as coronary stenosis <50%, has been increasingly recognized as an emerging entity in clinical practice. Vasomotion abnormality and coronary microvascular dysfunction are two major mechanisms contributing to the occur of angina with non-obstructive CAD. Although routine coronary functional assessment is limited due to several disadvantages, functional evaluation can help to understand the pathophysiological mechanism and/or to exclude specific etiologies. In this review, we summarized the potential mechanisms involved in ischemia with non-obstructive coronary arteries (INOCA) and myocardial infarction with non-obstructive coronary arteries (MINOCA), the two major form of non-obstructive CAD. Additionally, we reviewed currently available functional assessment indices and their use in non-obstructive CAD. Furthermore, we speculated that novel technique combined anatomic and physiologic parameters might provide more individualized therapeutic choice for patients with non-obstructive CAD.

Diagnostic accuracy of dynamic CZT-SPECT in coronary artery disease. A systematic review and meta-analysis

BACKGROUND

With the appearance of cadmium-zinc-telluride (CZT) cameras, dynamic myocardial perfusion imaging (MPI) has been introduced, but comparable data to other MPI modalities, such as quantitative coronary angiography (CAG) with fractional flow reserve (FFR) and positron emission tomography (PET), are lacking. This study aimed to evaluate the diagnostic accuracy of dynamic CZT single-photon emission tomography (SPECT) in coronary artery disease compared to quantitative CAG, FFR, and PET as reference.

MATERIALS AND METHODS

Different databases were screened for eligible citations performing dynamic CZT-SPECT against CAG, FFR, or PET. PubMed, OvidSP (Medline), Web of Science, the Cochrane Library, and EMBASE were searched on the 5th of July 2020. Studies had to meet the following pre-established inclusion criteria: randomized controlled trials, retrospective trails or observational studies relevant for the diagnosis of coronary artery disease, and performing CZT-SPECT and within half a year the methodological references. Studies which considered coronary stenosis between 50% and 70% as significant based only on CAG were excluded. Data extracted were sensitivity, specificity, likelihood ratios, and diagnostic odds ratios. Quality was assessed with QUADAS-2 and statistical analysis was performed using a bivariate model.

RESULTS

Based on our criteria, a total of 9 studies containing 421 patients were included. For the assessment of CZT-SPECT, the diagnostic value pooled analysis with a bivariate model was calculated and yielded a sensitivity of 0.79 (% CI 0.73 to 0.85) and a specificity of 0.85 (95% CI 0.74 to 0.92). Diagnostic odds ratio (DOR) was 17.82 (95% CI 8.80 to 36.08, P < 0.001). Positive likelihood ratio (PLR) and negative likelihood ratio (NLR) were 3.86 (95% CI 2.76 to 5.38, P < 0.001) and 0.21 (95% CI 0.13 to 0.33, P < 0.001), respectively.

CONCLUSION

Based on the results of the current systematic review and meta-analysis, dynamic CZT-SPECT MPI demonstrated a good sensitivity and specificity to diagnose CAD as compared to the gold standards. However, due to the heterogeneity of the methodologies between the CZT-SPECT MPI studies and the relatively small number of included studies, it warrants further well-defined study protocols.

Physiological Approach for Coronary Artery Bifurcation Disease: Position Statement by Korean, Japanese, and European Bifurcation Clubs

Coronary artery bifurcation lesions are frequently encountered in cardiac catheterization laboratories and are associated with more complex procedures and worse clinical outcomes than nonbifurcation lesions. Therefore, anatomical and physiological assessment of bifurcation lesions before, during, and after percutaneous coronary intervention is of paramount clinical importance. Physiological assessment can help interventionalists appreciate the hemodynamic significance of coronary artery disease and guide ischemia-directed revascularization. However, it is important to understand that the physiological approach for bifurcation disease is more important than simply using physiological indexes for its assessment. This joint consensus document by the Korean, Japanese, and European bifurcation clubs presents the concept of a physiological approach for coronary bifurcation lesions, as well as current knowledge, practical tips, pitfalls, and future directions of applying physiological indexes in bifurcation percutaneous coronary intervention. This document aims to guide interventionalists in performing appropriate physiology-based assessments and treatment decisions for coronary bifurcation lesions.

Reclassification of Treatment Strategy with Fractional Flow Reserve in Cancer Patients with Coronary Artery Disease

Background and Objectives: Cancer and coronary artery disease (CAD) often coexist. Compared to quantitative coronary angiography (QCA), fractional flow reserve (FFR) has emerged as a more reliable method of identifying significant coronary stenoses. We aimed to assess the specific management, safety and outcomes of FFR-guided percutaneous coronary intervention (PCI) in cancer patients with stable CAD. Materials and Methods: FFR was used to assess cancer patients that underwent coronary angiography for stable CAD between September 2008 and May 2016, and were found to have ≥50% stenosis by QCA. Patients with lesions with an FFR > 0.75 received medical therapy alone, while those with FFR ≤ 0.75 were revascularized. Procedure-related complications, all-cause mortality, nonfatal myocardial infarction, or urgent revascularizations were analyzed. Results: Fifty-seven patients with stable CAD underwent FFR on 57 lesions. Out of 31 patients with ≥70% stenosis as measured by QCA, 14 (45.1%) had an FFR ≥ 0.75 and lesions were reclassified as moderate and did not receive PCI nor DAPT. Out of 26 patients with <70% stenosis as measured by QCA, 6 (23%) had an FFR < 0.75 and were reclassified as severe and were treated with PCI and associated DAPT. No periprocedural complications, urgent revascularization, acute coronary syndromes, or cardiovascular deaths were noted. There was a 22.8% mortality at 1 year, all cancer related. Patients who received a stent by FFR assessment showed a significant association with decreased risk of all-cause death (HR: 0.37, 95% CI 0.15−0.90, p = 0.03). Conclusions: Further studies are needed to define the optimal therapeutic approach for cancer patients with CAD. Using an FFR cut-off point of 0.75 to guide PCI translates into fewer interventions and can facilitate cancer care. There was an overall reduction in mortality in patients that received a stent, suggesting increased resilience to cancer therapy and progression.

Improved Functional Assessment of Ischemic Severity Using 3D Printed Models

Objective

To develop a novel in vitro method for evaluating coronary artery ischemia using a combination of non-invasive coronary CT angiograms (CCTA) and 3D printing (FFR_3D).

Methods

Twenty eight patients with varying degrees of coronary artery disease who underwent non-invasive CCTA scans and invasive fractional flow reserve (FFR) of their epicardial coronary arteries were included in this study. Coronary arteries were segmented and reconstructed from CCTA scans using Mimics (Materialize). The segmented models were then 3D printed using a Carbon M1 3D printer with urethane methacrylate (UMA) family of rigid resins. Physiological coronary circulation was modeled in vitro as flow-dependent stenosis resistance in series with variable downstream resistance. A range of physiological flow rates (Q) were applied using a peristaltic steady flow pump and titrated with a flow sensor. The pressure drop (ΔP) and the pressure ratio (P_d/P_a) were assessed for patient-specific aortic pressure (P_a) and differing flow rates (Q) to evaluate FFR_3D using the 3D printed model.

Results

There was a good positive correlation (r = 0.87, p < 0.0001) between FFR_3D and invasive FFR. Bland-Altman analysis revealed a good concordance between the FFR_3D and invasive FFR values with a mean bias of 0.02 (limits of agreement: −0.14 to 0.18; p = 0.2).

Conclusions

3D printed patient-specific models can be used in a non-invasive in vitro environment to quantify coronary artery ischemia with good correlation and concordance to that of invasive FFR.

Diagnostic Performance of CCTA and CT-FFR for the Detection of CAD in TAVR Work-Up

BACKGROUND

The work-up for transcatheter aortic valve replacement (TAVR) currently uses computed tomography to evaluate the annulus diameter and peripheral vascular access plus invasive coronary angiography (ICA) to assess significant coronary artery disease (CAD). ICA might partially be redundant with the use of coronary computed tomography angiography (CCTA). Prior studies found an improvement of the diagnostic accuracy of CCTA with the use of computed tomography-derived fractional flow reserve (CT-FFR).

OBJECTIVES

The aim of this study was to assess the diagnostic performance of CT-FFR for the diagnosis of CAD in the work-up for TAVR.

METHODS

Consecutive patients with severe symptomatic aortic valve stenosis who underwent TAVR work-up between 2015 and 2019 were included in this retrospective cross-sectional study. All patients underwent CCTA and ICA within 3 months, and the diagnostic performance of both CCTA and CT-FFR was assessed using ICA as the reference.

RESULTS

Seventy-six of the 338 patients included in the analysis had ≥1 significant coronary stenosis on ICA. The sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy per patient were 76.9%, 64.5%, 34.0%, 92.1%, and 66.9% for CCTA and 84.6%, 88.3%, 63.2%, 96.0%, and 87.6% for CT-FFR. The area under the receiver-operating characteristic curve was significantly different between CCTA and CT-FFR (0.84 vs 0.90, P = 0.02). A CT-FFR-guided approach could avoid ICA in 57.1% versus 43.6% of patients using CCTA.

CONCLUSIONS

CT-FFR significantly improves the diagnostic accuracy of CCTA without additional testing and increases the proportion of patients in whom ICA could have been safely avoided. It has the potential to be integrated in the current clinical work-up for TAVR for diagnosing stable CAD requiring treatment.

Functional Evaluation of Intermediate Coronary Lesions with Integrated Computed Tomography Angiography and Invasive Angiography in Patients with Stable Coronary Artery Disease

Background and objectives

The hemodynamic evaluation of coronary stenoses undergoes a transition from wire-based invasive measurements to image-based computational assessments. However, fractional flow reserve (FFR) values derived from coronary CT angiography (CCTA) and angiography-based quantitative flow ratio have certain limitations in accuracy and efficiency, preventing their widespread use in routine practice. Hence, we aimed to investigate the diagnostic performance of FFR derived from the integration of CCTA and invasive angiography (FFR_CT-angio) with artificial intelligence assistance in patients with stable coronary artery disease (CAD).

Methods

Forty stable CAD patients with 67 target vessels (50%-90% diameter stenosis) were included in this single-center retrospective study. All patients underwent CCTA followed by coronary angiography with FFR measurement within 30 days. Both CCTA and angiographic images were combined to generate a three-dimensional reconstruction of the coronary arteries using artificial intelligence. Subsequently, functional assessment was performed through a deep learning algorithm. FFR was used as the reference.

Results

FFR_CT-angio values were significantly correlated with FFR values (r = 0.81, P < 0.001, Spearman analysis). Per-vessel diagnostic accuracy of FFR_CT-angio was 92.54%. Sensitivity and specificity in identifying ischemic lesions were 100% and 88.10%, respectively. Positive predictive value and negative predictive value were 83.33% and 100%, respectively. Moreover, the diagnostic performance of FFR_CT-angio was satisfactory in different target vessels and different segment lesions.

Conclusions

FFR_CT-angio exhibits excellent diagnostic performance of identifying ischemic lesions in patients with stable CAD. Combining CCTA and angiographic imaging, FFR_CT-angio may represent an effective and practical alternative to invasive FFR in selected patients.

Clinical Outcomes Following Hemodynamic Parameter or Intravascular Imaging-Guided Percutaneous Coronary Intervention in the Era of Drug-Eluting Stents: An Updated Systematic Review and Bayesian Network Meta-Analysis of 28 Randomized Trials and 11,860 Patients

Background

Coronary angiography (CAG) is the standard imaging modality for guiding percutaneous coronary interventions (PCI). Intracoronary imaging techniques such as intravascular ultrasound (IVUS) and optical coherence tomography (OCT), and hemodynamic parameter like fractional flow reserve (FFR) can overcome some limitations of CAG.

Objective

We sought to explore the clinical outcomes of different PCI guidance modalities in the era of drug-eluting stent (DES).

Methods

A network meta-analysis of 28 randomized trials and 11,860 patients undergoing different modalities-guided PCI in the era of DES was performed. Odds ratio (OR) with 95% credible interval (CrI) were calculated.

Results

In comparison with CAG, IVUS was associated with a significant reduction in major adverse cardiovascular events (MACE, OR: 0.60; 95% CrI: 0.46–0.79), cardiovascular death (OR: 0.46; 95% CrI: 0.20–0.94), target vessel/lesion revascularization (TVR/TLR, OR: 0.55; 95% CrI: 0.41–0.74), and a trend toward decreased risk of stent thrombosis (OR: 0.44; 95% CrI: 0.17 to 1.00). FFR/quantitative flow ratio (QFR) could significantly reduce stroke compared with CAG, IVUS, and OCT/optical frequency domain imaging (OFDI). However, myocardial infarction (MI), all-cause death, stent thrombosis, and any revascularization presented similar risks for different PCI guidance modalities.

Conclusion

In the era of DES, IVUS led to lower risks of MACE than CAG, which was mainly due to lower risks of cardiovascular death and TVR/TLR. A trend toward decreased risk of stent thrombosis was also observed with IVUS. Hemodynamic parameter (FFR/QFR)-guided PCI could significantly reduce the stroke risk compared with CAG, IVUS, and OCT/OFDI.

Systematic Review Registration

[https://www.crd.york.ac.uk/PROSPERO/], identifier [CRD42021291442].

Characterization of quantitative flow ratio and fractional flow reserve discordance using doppler flow and clinical follow-up

The physiological mechanisms of quantitative flow ratio and fractional flow reserve disagreement are not fully understood. We aimed to characterize the coronary flow and resistance profile of intermediate stenosed epicardial coronary arteries with concordant and discordant FFR and QFR. Post-hoc analysis of the DEFINE-FLOW study. Anatomical and Doppler-derived physiological parameters were compared for lesions with FFR+QFR- (n = 18) vs. FFR+QFR+ (n = 43) and for FFR-QFR+ (n = 34) vs. FFR-QFR- (n = 139). The association of QFR results with the two-year rate of target vessel failure was assessed in the proportion of vessels (n = 195) that did not undergo revascularization. Coronary flow reserve was higher [2.3 (IQR: 2.1-2.7) vs. 1.9 (IQR: 1.5-2.4)], hyperemic microvascular resistance lower [1.72 (IQR: 1.48-2.31) vs. 2.26 (IQR: 1.79-2.87)] and anatomical lesion severity less severe [% diameter stenosis 45.5 (IQR: 41.5-52.5) vs. 58.5 (IQR: 53.1-64.0)] for FFR+QFR- lesions compared with FFR+QFR+ lesions. In comparison of FFR-QFR+ vs. FFR-QFR- lesions, lesion severity was more severe [% diameter stenosis 55.2 (IQR: 51.7-61.3) vs. 43.4 (IQR: 35.0-50.6)] while coronary flow reserve [2.2 (IQR: 1.9-2.9) vs. 2.2 (IQR: 1.9-2.6)] and hyperemic microvascular resistance [2.34 (IQR: 1.85-2.81) vs. 2.57 (IQR: 2.01-3.22)] did not differ. The agreement and diagnostic performance of FFR using hyperemic stenosis resistance (> 0.80) as reference standard was higher compared with QFR and coronary flow reserve. Disagreement between FFR and QFR is partly explained by physiological and anatomical factors. Clinical Trials Registration https://www.clinicaltrials.gov ; Unique identifier: NCT01813435.

Combined Assessment of FFR and CFR for Decision Making in Coronary Revascularization: From the Multicenter International ILIAS Registry

OBJECTIVES

The aim of this study was to demonstrate the clinical implications of combined assessment of fractional flow reserve (FFR) and coronary flow reserve (CFR).

BACKGROUND

Combined assessment of FFR and CFR allows detailed characterization of pathophysiology in chronic coronary syndromes. Data on the clinical implications of distinct FFR and CFR patterns are limited, leading to uncertainty regarding their relevance.

METHODS

Patients with chronic coronary syndromes and obstructive coronary artery disease were selected from the multicenter ILIAS (Inclusive Invasive Physiological Assessment in Angina Syndromes) registry. Patients were classified into 4 groups on the basis of FFR ≤0.80 and CFR <2.0. The endpoint was the 5-year target vessel failure (TVF) rate.

RESULTS

A total of 2,143 patients with 2,725 lesions were included. Compared with normal FFR/normal CFR, low FFR/low CFR carried the highest risk for TVF (HR: 5.4; 95% CI: 3.2-9.3; P < 0.001), significantly higher than in revascularized vessels (P = 0.007). Discordance, with either low FFR/normal CFR or normal FFR/low CFR, was associated with increased TVF rates compared with normal FFR/normal CFR (low FFR/normal CFR: HR: 3.5 [95% CI: 2.2-5.4; P < 0.001]; normal FFR/low CFR: HR: 3.0 [95% CI: 1.9-4.7; P < 0.001]). No difference in 5-year TVF was observed between the 2 discordant groups (P = 0.57) or between the discordant groups and the revascularized group (P = 0.26 vs low FFR/normal CFR; P = 0.60 vs normal FFR/low CFR).

CONCLUSIONS

Impaired coronary hemodynamics are uniformly associated with increased 5-year TVF rates. Nonrevascularized vessels with discordant FFR and CFR are associated with 5-year event rates that are equivalent to those of vessels that undergo revascularization, whereas vessels with combined low FFR and CFR exhibit event rates that are significantly higher than after revascularization. (Inclusive Invasive Physiological Assessment in Angina Syndromes Registry [ILIAS Registry]; NCT04485234).

Differential Prognostic Value of Revascularization for Coronary Stenosis With Intermediate FFR by Coronary Flow Reserve

OBJECTIVES

The authors sought to evaluate comparative prognosis between deferred versus performed percutaneous coronary intervention (PCI) according to coronary flow reserve (CFR) values of patients with intermediate fractional flow reserve (FFR).

BACKGROUND

For coronary stenosis with intermediate FFR, the prognostic value of PCI remains controversial. The prognostic impact of PCI may be different according to CFR in patients with intermediate FFR.

METHODS

From the ILIAS Registry (Inclusive Invasive Physiological Assessment in Angina Syndromes Registry, N = 2,322), 400 patients (412 vessels) with intermediate FFR (0.75-0.80) were selected. Patients were stratified into preserved CFR (>2.0, n = 253) and depressed CFR (≤2.0, n = 147) cohorts. Per-vessel clinical outcomes during 5 years of follow-up were compared between deferred versus performed PCI groups in both cohorts. The primary outcome was target vessel failure (TVF), a composite of cardiac death, target vessel myocardial infarction, or target vessel revascularization.

RESULTS

Among the study population, PCI was deferred for 210 patients (219 vessels, 53.2%) (deferred group) and performed for 190 patients (193 vessels, 46.8%) (performed group). The risk of TVF was comparable between the deferred and performed groups (12.8% vs 14.2%; adjusted HR: 1.403; 95% CI: 0.584-3.369; P = 0.448). When stratified by CFR, PCI was performed in 39.1% (100/261 vessels) of the preserved CFR cohort and 61.9% (93/151 vessels) of the depressed CFR cohort. Within the preserved CFR cohort, the risk of TVF did not differ significantly between the deferred and performed groups (11.0% vs 13.9%; adjusted HR: 0.770; 95% CI: 0.262-2.266; P = 0.635). However, in the depressed CFR cohort, the deferred group had a significantly higher risk of TVF than the performed group (17.2% vs 14.2%; adjusted HR: 4.932; 95% CI: 1.312-18.53; P = 0.018). A significant interaction was observed between CFR and the treatment decision (interaction P = 0.049). Results were consistent after inverse probability weighting adjustment.

CONCLUSIONS

In patients with intermediate FFR of 0.75 to 0.80, the prognostic value of PCI differed according to CFR, with a significant interaction. PCI was associated with a lower risk of TVF compared with the deferral strategy when CFR was depressed (≤2.0), but there was no difference when CFR was preserved (>2.0). CFR could be used as an additional risk stratification tool to determine treatment strategies in patients with intermediate FFR. (Inclusive Invasive Physiological Assessment in Angina Syndromes Registry [ILIAS Registry]; NCT04485234).

Fractional flow reserve versus angiography alone in guiding myocardial revascularisation: a systematic review and meta-analysis of randomised trials

BACKGROUND

Randomised trials evaluating the efficacy and safety of fractional flow reserve (FFR)-guided versus angiography-guided revascularisation among patients with obstructive coronary artery disease (CAD) have yielded mixed results.

AIMS

To examine the comparative efficacy and safety of FFR-guided versus angiography-guided revascularisation among patients with obstructive CAD.

METHODS

An electronic search of MEDLINE, SCOPUS and Cochrane databases without language restrictions was performed through November 2021 for randomised controlled trials that evaluated the outcomes of FFR-guided versus angiography-guided revascularisation. The primary outcome was major adverse cardiac events (MACE). Data were pooled using a random-effects model.

RESULTS

The final analysis included seven trials with 5094 patients. The weighted mean follow-up duration was 38 months. Compared with angiography guidance, FFR guidance was associated with fewer number of stents during revascularisation (standardised mean difference=-0.80; 95% CI -1.33 to -0.27), but no difference in total hospital cost. There was no difference between FFR-guided and angiography-guided revascularisation in long-term MACE (13.6% vs 13.9%; risk ratio (RR) 0.97, 95% CI 0.85 to 1.11). Meta-regression analyses did not reveal any evidence of effect modification for MACE with acute coronary syndrome (p=0.36), proportion of three-vessel disease (p=0.88) or left main disease (p=0.50). There were no differences between FFR-guided and angiography-guided revascularisation in the outcomes all-cause mortality (RR 1.16, 95% CI 0.80 to 1.68), cardiovascular mortality (RR 1.27, 95% CI 0.50 to 3.26), repeat revascularisation (RR 0.99, 95% CI 0.81 to 1.21), recurrent myocardial infarction (RR 0.92, 95% CI 0.74 to 1.14) or stent thrombosis (RR 0.61, 95% CI 0.31 to 1.21).

CONCLUSION

Among patients with obstructive CAD, FFR-guided revascularisation did not reduce the risk of long-term adverse cardiac events or the individual outcomes. However, FFR-guided revascularisation was associated with fewer number of stents.

PROSPERO REGISTRATION NUMBER

CRD42021291596.

Physiologic Lesion Assessment to Optimize Multivessel Disease

PURPOSE OF REVIEW

Multivessel coronary artery disease, defined as significant stenosis in two or more major coronary arteries, is associated with high morbidity and mortality. The diagnosis and treatment of multivessel disease have evolved in the PCI era from solely a visual estimation of ischemic risk to a functional evaluation during angiography. This review summarizes the evidence and discusses the commonly used methods of multivessel coronary artery stenosis physiologic assessment.

RECENT FINDINGS

While FFR remains the gold standard in coronary physiologic assessment, several pressure-wire-based non-hyperemic indices of functional stenosis have been developed and validated as well as wire-free angiographically derived quantitative flow ratio. Identifying and treating functionally significant coronary atherosclerotic lesions reduce symptoms and major adverse cardiovascular events. Coronary physiologic assessment in multivessel disease minimizes the observer bias in visual estimates of stenosis, changes clinical management, and improves patient outcomes.

Contemporary Management of Stable Coronary Artery Disease

Coronary artery disease (CAD) continues to be the leading cause of mortality and morbidity in developed countries. Assessment of pre-test probability (PTP) based on patient's characteristics, gender and symptoms, help to identify more accurate patient's clinical likelihood of coronary artery disease. Consequently, non-invasive imaging tests are performed more appropriately to rule in or rule out CAD rather than invasive coronary angiography (ICA). Coronary computed tomography angiography (CCTA) is the first-line non-invasive imaging technique in patients with suspected CAD and could be used to plan and guide coronary intervention. Invasive coronary angiography remains the gold-standard method for the identification and characterization of coronary artery stenosis. However, it is recommended in patients where the imaging tests are non-conclusive, and the clinical likelihood is very high, remembering that in clinical practice, approximately 30 to 70% of patients with symptoms and/or signs of ischemia, referred to coronary angiography, have non obstructive coronary artery disease (INOCA). In this contest, physiology and imaging-guided revascularization represent the cornerstone of contemporary management of chronic coronary syndromes (CCS) patients allowing us to focus specifically on ischemia-inducing stenoses. Finally, we also discuss contemporary medical therapeutic approach for secondary prevention. The aim of this review is to provide an updated diagnostic and therapeutic approach for the management of patients with stable coronary artery disease.

Coronary Flow Variations Following Percutaneous Coronary Intervention Affect Diastolic Nonhyperemic Pressure Ratios More Than the Whole Cycle Ratios

Background Post-percutaneous coronary intervention (PCI) fractional flow reserve ≥0.90 is an accepted marker of procedural success, and a cutoff of ≥0.95 has recently been proposed for post-PCI instantaneous wave-free ratio. However, stability of nonhyperemic pressure ratios (NHPRs) post-PCI is not well characterized, and transient reactive submaximal hyperemia post-PCI may affect their precision. We performed this study to assess stability and reproducibility of NHPRs post-PCI. Methods and Results Fifty-seven patients (age, 63.77±10.67 years; men, 71%) underwent hemodynamic assessment immediately post-PCI and then after a recovery period of 10, 20, and 30 minutes and repeated at 3 months. Manual offline analysis was performed to derive resting and hyperemic pressure indexes (Pd/Pa resting pressure gradient, mathematically derived instantaneous wave-free ratio, resting full cycle ratio, and fractional flow reserve) and microcirculatory resistances (basal microvascular resistance and index of microvascular resistance). Transient submaximal hyperemia occurring post-PCI was demonstrated by longer thermodilution time at 30 minutes compared with immediately post-PCI; mean difference of thermodilution time was 0.17 seconds (95% CI, 0.07-0.26 seconds; P=0.04). Basal microcirculatory resistance was also higher at 30 minutes than immediately post-PCI; mean difference of basal microvascular resistance was 10.89 mm Hg.s (95% CI, 2.25-19.52 mm Hg.s; P=0.04). Despite this, group analysis confirmed no significant differences in the values of resting whole cycle pressure ratios (Pd/Pa and resting full cycle ratio) as well as diastolic pressure ratios (diastolic pressure ratio and mathematically derived instantaneous wave-free ratio). Whole cardiac cycle NHPRs demonstrated the best overall stability post-PCI, and 1 in 5 repeated diastolic NHPRs crossed the clinical decision threshold. Conclusions Whole cycle NHPRs demonstrate better reproducibility and clinical precision post-PCI than diastolic NHPRs, possibly because of less perturbation from predominantly diastolic reactive hyperemia and left ventricular stunning. Registration URL: https://clinicaltrials.gov/ct2/show/NCT03502083; Unique identifier: NCT03502083 and URL: https://clinicaltrials.gov/ct2/show/NCT03076476; Unique identifier: NCT03076476.

Feasibility and Comparison of Resting Full-Cycle Ratio and Computed Tomography Fractional Flow Reserve in Patients with Severe Aortic Valve Stenosis

Background: Computed tomography derived Fractional Flow Reserve (CT-FFR) has been shown to decrease the referral rate for invasive coronary angiography (ICA). The purpose of the study was to evaluate the diagnostic performance of CT-FFR compared to hyperemia-free index Resting Full-cycle Ratio (RFR) in patients with relevant aortic stenosis (AS) and intermediate coronary stenosis. Methods: 41 patients with 46 coronary lesions underwent ICA with quantitative coronary angiography (QCA), pressure wire assessment and routine pre-transcatheter aortic valve replacement (TAVR) computed tomography (CT). CT-FFR analysis was performed using prototype on-site software. Results: RFR showed a significant correlation with CT-FFR (Pearson’s correlation, r = 0.632, p < 0.001). On a per-lesion basis, diagnostic accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of CT-FFR were 82.6% (95% CI 68.6−92.2), 69.6% (95% CI 47.1−86.8), 95.7% (95% CI  78.1−99.9), 94.1% (95% CI 69.8−99.1), and 75.9% (95% CI 62.7−85.4), respectively. The optimal cutoff value of the CT-FFR for RFR ≤ 0.89 prediction was 0.815. The area under the receiver curve showed a larger area under the curve for CT-FFR (0.87; 95% CI 0.75−0.98) compared with CTA stenosis of ≥50% (0.54, 95% CI 0.38−0.71), CTA ≥ 70% (0.72, 95% CI 0.57−0.87) and QCA ≥ 50% (0.67, 95% CI 0.52−0.83). Conclusions: CT-FFR assessed by routine pre-TAVR CT is safe and feasible and shows a significant correlation with RFR in patients with AS. CT-FFR is superior to QCA ≥ 50%, CT ≥ 50% and CT ≥ 70% in assessing the hemodynamic relevance of intermediate coronary lesions. Thus, CT-FFR has the potential to guide revascularization in patients with AS.

Quantitative Flow Ratio or Angiography for the Assessment of Non-culprit Lesions in Acute Coronary Syndromes: Protocol of the Randomized Trial QUOMODO

Background

Approximately 50% of the patients undergoing percutaneous coronary intervention (PCI) for acute coronary syndromes (ACS) have additional stenotic lesions in non-infarct-related coronary arteries. The decision whether these stenoses require further treatment is routinely based on angiography alone. The quantitative flow ratio (QFR) is a simple non-invasive method that may help quantify the functional significance of these intermediate coronary artery lesions. The aim of our single-center, randomized superiority trial is to test the impact and efficacy of QFR, as compared to angiography, in the treatment of patients with ACS with multivessel coronary artery disease. Primary goal of the study is to investigate 1. The impact of QFR on the proportion of patients receiving PCI vs. conservative therapy and 2. whether QFR improves angina pectoris and overall cardiovascular outcomes.

Methods and Analysis

After treatment of the culprit lesion(s), a total of 200 consecutive ACS patients will be randomized 1:1 to angiography- vs. QFR-guided revascularization of non-culprit stenoses. Patients and clinicians responsible are blinded to the randomization group. The primary functional endpoint is defined as the proportion of patients assigned to medical treatment in the two groups. The primary clinical endpoint is a composite of death, non-fatal myocardial infarction, revascularization and significant angina at 12 months. Secondary endpoints include changes in the SAQ subgroups, and clinical events at 3- and 12-month follow-up.

Discussion

This study is designed to investigate whether QFR-based decision-making is associated with a decrease in angina and an improved prognosis in patients with multivessel disease.

Trial Registration Number

ClinicalTrials.gov Registry (NCT04808310).

The Relationship Between Attachment and Self-Injurious Behaviors in the Child and Adolescent Population: A Systematic Review of the Literature

Adolescents have high rates of self-injurious behavior (SIB), with suicide being the second leading cause of death. A consistent relationship between individual attachment and SIB was previously found in adult population; however, no such review has been undertaken for the child and adolescent population. A systematic search of PubMED, OVID, and PsychINFO up to March 31, 2020 was performed. Twenty-two articles met the inclusion criteria. Of the 22 articles, 21 found a positive association between attachment insecurity and SIB. Our results show a consistent relationship between attachment insecurity and SIB in children and adolescents, complementing the results found in the adult literature. These findings make a case for preventive strategies aimed at reducing self-injurious behaviors in youth by targeting attachment security.

Effects of diabetes mellitus on post-intervention coronary physiological assessment derived by quantitative flow ratio in patients with coronary artery disease underwent percutaneous coronary intervention

AIMS

To compare the prognostic implication of post-percutaneous coronary intervention (PCI) quantitative flow ratio (QFR) assessment in patients with and without diabetes enrolled in the all-comers, multicenter, randomized controlled PANDA III trial.

METHODS

All treated vessels in PANDA III trial were retrospectively assessed for post-PCI QFR. Vessels with available post-PCI QFR were further stratified into DM and non-DM cohorts, and prognostic performance of post-PCI QFR was compared in 2 cohorts. The primary outcome was 2-year vessel-oriented composite endpoint (VOCE), defined as composite of vessel-related cardiac death, vessel-related non-procedural myocardial infarction, and ischemia-driven target vessel revascularization.

RESULTS

Of 2,989 treated vessels, 2,227 (74.5%) with available post-PCI QFR were included, while 548 were presence of DM and 1,679 were not. The performance of post-PCI QFR to predict 2-year VOCE were moderate in both DM (area under the curve [AUC] 0.77, 95% confidence interval [CI]: 0.68 to 0.87) and non-DM cohorts (AUC 0.74, 95% CI: 0.67 to 0.82), while between-cohorts AUC difference was not significant (ΔAUC 0.03, P = 0.65). After multivariate adjustment, vessels with suboptimal post-PCI QFR results (≤0.92) were associated with higher risk of 2-year VOCE in both DM (adjusted HR 6.24, 95% CI: 2.40 to 16.2) and non-DM cohorts (adjusted HR 5.92, 95% CI: 3.28 to 10.7) without significant interaction (P for interaction 0.91).

CONCLUSIONS

This study, the first to directly compare clinical value of post-PCI QFR assessments in patients with and without DM, showed that a higher post-PCI QFR value was associated with improved long-term prognosis regardless of the presence of DM. Clinical Trial Registration Information URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT02017275.

Functional significance of intermediate coronary stenosis in patients with single-vessel coronary artery disease: A comparison of dynamic SPECT coronary flow reserve with intracoronary pressure-derived fractional flow reserve (FFR)

BACKGROUND

The aim of this study was to investigate the correlation of coronary flow reserve (CFR) assessed by rest/stress myocardial perfusion imaging with dynamic single-photon emission computed tomography (SPECT) with intracoronary pressure-derived fractional flow reserve (FFR) in patients with single-vessel coronary artery disease (CAD).

METHODS

Patients with suspected or known stable CAD who were referred for invasive coronary angiography were prospectively enrolled. Both invasive FFR and SPECT were performed in subjects with single-vessel intermediate coronary stenosis. A cutoff value of < 0.8 was used to define abnormal FFR.

RESULTS

A total of 34 patients were enrolled. The mean age of the subjects was 62.1 ± 6.7 years, and 79.4% were male. SPECT-derived CFR showed a significantly moderate correlation with FFR (r = 0.505, P = .003). The diagnostic performance for the identification of abnormal FFR in terms of sensitivity, specificity, and accuracy was 88.9%, 83.3%, and 87.9%, respectively, for CFR, with an optimized cutoff value of 1.73.

CONCLUSION

In patients with single-vessel CAD, SPECT CFR was useful for the detection of functionally significant stenosis. Our data support the use of this technique as an optional method for hemodynamic assessment, especially when FFR results are in normal range.

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

BACKGROUND

Instantaneous 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.

OBJECTIVES

The 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.

METHODS

iFR-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.

RESULTS

No 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.

CONCLUSIONS

In 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).

Challenges in Diagnosis and Functional Assessment of Coronary Artery Disease in Patients With Severe Aortic Stenosis

More than half of patients with severe aortic stenosis (AS) over 70 years old have coronary artery disease (CAD). Exertional angina is often present in AS-patients, even in the absence of significant CAD, as a result of oxygen supply/demand mismatch and exercise-induced myocardial ischemia. Moreover, persistent myocardial ischemia leads to extensive myocardial fibrosis and subsequent coronary microvascular dysfunction (CMD) which is defined as reduced coronary vasodilatory capacity below ischemic threshold. Therefore, angina, as well as noninvasive stress tests, have a low specificity and positive predictive value (PPV) for the assessment of epicardial coronary stenosis severity in AS-patients. Moreover, in symptomatic patients with severe AS exercise testing is even contraindicated. Given the limitations of noninvasive stress tests, coronary angiography remains the standard examination for determining the presence and severity of CAD in AS-patients, although angiography alone has poor accuracy in the evaluation of its functional severity. To overcome this limitation, the well-established invasive indices for the assessment of coronary stenosis severity, such as fractional flow reserve (FFR) and instantaneous wave-free ratio (iFR), are now in focus, especially in the contemporary era with the rapid increment of transcatheter aortic valve replacement (TAVR) for the treatment of AS-patients. TAVR induces an immediate decrease in hyperemic microcirculatory resistance and a concomitant increase in hyperemic flow velocity, whereas resting coronary hemodynamics remain unaltered. These findings suggest that FFR may underestimate coronary stenosis severity in AS-patients, whereas iFR as the non-hyperemic index is independent of the AS severity. However, because resting coronary hemodynamics do not improve immediately after TAVR, the coronary vasodilatory capacity in AS-patients treated by TAVR remain impaired, and thus the iFR may overestimate coronary stenosis severity in these patients. The optimal method for evaluating myocardial ischemia in patients with AS and co-existing CAD has not yet been fully established, and this important issue is under further investigation. This review is focused on challenges, limitations, and future perspectives in the functional assessment of coronary stenosis severity in these patients, bearing in mind the complexity of coronary physiology in the presence of this valvular heart disease.

Artificial Intelligence in Cardiovascular Atherosclerosis Imaging

At present, artificial intelligence (AI) has already been applied in cardiovascular imaging (e.g., image segmentation, automated measurements, and eventually, automated diagnosis) and it has been propelled to the forefront of cardiovascular medical imaging research. In this review, we presented the current status of artificial intelligence applied to image analysis of coronary atherosclerotic plaques, covering multiple areas from plaque component analysis (e.g., identification of plaque properties, identification of vulnerable plaque, detection of myocardial function, and risk prediction) to risk prediction. Additionally, we discuss the current evidence, strengths, limitations, and future directions for AI in cardiac imaging of atherosclerotic plaques, as well as lessons that can be learned from other areas. The continuous development of computer science and technology may further promote the development of this field.

Cardiac CT angiography in current practice: An American society for preventive cardiology clinical practice statement✰

In this clinical practice statement, we represent a summary of the current evidence and clinical applications of cardiac computed tomography (CT) in evaluation of coronary artery disease (CAD), from an expert panel organized by the American Society for Preventive Cardiology (ASPC), and appraises the current use and indications of cardiac CT in clinical practice. Cardiac CT is emerging as a front line non-invasive diagnostic test for CAD, with evidence supporting the clinical utility of cardiac CT in diagnosis and prevention. CCTA offers several advantages beyond other testing modalities, due to its ability to identify and characterize coronary stenosis severity and pathophysiological changes in coronary atherosclerosis and stenosis, aiding in early diagnosis, prognosis and management of CAD. This document further explores the emerging applications of CCTA based on functional assessment using CT derived fractional flow reserve, peri‑coronary inflammation and artificial intelligence (AI) that can provide personalized risk assessment and guide targeted treatment. We sought to provide an expert consensus based on the latest evidence and best available clinical practice guidelines regarding the role of CCTA as an essential tool in cardiovascular prevention - applicable to risk assessment and early diagnosis and management, noting potential areas for future investigation.

Peripheral Coronary Artery Circulatory Dysfunction in Remote Stage Kawasaki Disease Patients Detected by Adenosine Stress 13N-Ammonia Myocardial Perfusion Positron Emission Tomography

Coronary peripheral circulatory disturbances in the remote stage of Kawasaki disease have been reported. In this study, of the 50 patients in the remote stage of Kawasaki disease who underwent coronary perfusion evaluation using adenosine-loaded ¹³N-ammonia positron emission tomography, 28 patients who did not have stenosis of ≥75% in the left coronary artery underwent an evaluation for myocardial flow reserve (MFR) of the left anterior descending artery (LAD) and left circumflex artery (LCx). Clinical findings were compared between patients with normal (≥2.0) and abnormal (<2.0) MFRs. In the group with an abnormal MFR in the LAD, the responsiveness of the coronary vascular resistance to adenosine stress decreased even in the LCx (3.50 ± 1.23 vs. 2.39 ± 0.25, p = 0.0100). In the group with an abnormal MFR in the LCx, the responsiveness of the coronary vascular resistance in the LAD also decreased (3.27 ± 1.39 vs. 2.03 ± 0.25, p = 0.0105), and the age of onset of Kawasaki disease tended to be younger in the group with abnormal MFR in the LAD and LCx. We found that the peripheral coronary circulation was extensively impaired in the remote stage of Kawasaki disease, suggesting that an early onset of Kawasaki disease may affect the peripheral coronary circulation in later years.

Outcomes of quantitative flow ratio-based percutaneous coronary intervention in an all-comers study

BACKGROUND

Quantitative flow ratio (QFR) is a novel angiography-based physiological index for fast computation of fractional flow reserve without the use of a pressure wire or induction of hyperaemia.

AIMS

We sought to investigate the prevalence and prognostic implications of achieving physiology-consistent percutaneous coronary intervention (PCI) according to the baseline angiographic QFR in an all-comers cohort.

METHODS

QFR was retrospectively analysed from the angiograms of 1,391 patients enrolled in the randomised PANDA III trial. Patients in whom all functionally ischaemic vessels (baseline QFR ≤0.80) were treated and in whom all non-ischaemic vessels (baseline QFR >0.80) were deferred were termed as having had QFR-consistent treatment; otherwise, they were termed as having had QFR-inconsistent treatment. The major outcome was two-year major adverse cardiac events (MACE; a composite of all-cause death, all myocardial infarction (MI), or any ischaemia-driven revascularisation).

RESULTS

Overall, 814 (58.5%) patients had QFR-consistent PCI, while 577 (41.5%) patients received QFR-inconsistent PCI. Patients with QFR-consistent versus those with QFR-inconsistent treatment had a lower risk of two-year MACE (8.4% vs 14.7%; hazard ratio [HR] 0.56, 95% confidence interval [CI]: 0.41-0.78). After adjusting for differences in baseline covariates, two-year rates of MACE remained significantly lower in the QFR-consistent group (8.8% vs 13.6%; adjusted HR 0.64, 95% CI: 0.44-0.93), due mainly to reduced ischaemia-driven revascularisation (2.9% vs 8.0%; adjusted HR 0.35, 95% CI: 0.20-0.60).

CONCLUSIONS

In this post hoc analysis of an all-comers PCI trial, approximately 60% of patients were treated in accordance with what the QFR measurement would have recommended, the achievement of which was associated with improved two-year clinical outcomes. ClinicalTrials.gov identifier: NCT02017275.

Computed tomography coronary angiography as the noninvasive in stable coronary artery disease? Long-term outcomes meta-analysis

Aim: To compare outcomes of coronary computed tomography angiography (CCTA) with that of functional testing (FT) in stable coronary artery disease. Methods: We searched PubMed, Embase, and Cochrane for randomized controlled trials (RCTs). A random-effects meta-analysis targeting all-cause death and nonfatal acute coronary syndromes was performed. Results: Eight RCTs enrolling 29,579 patients were included. Pooled relative risk (RR) for the primary end point was similar between CCTA and FT (RR = 0.97; 95% CI: 0.76-1.22). CCTA outperformed FT in nonfatal myocardial infarction (MI) (RR = 0.59; 95% CI: 0.41-0.83) and in downstream testing (OR: 0.47; 95% CI: 0.21-1.01). Conclusion: Updated data of stable coronary artery disease suggests that CCTA improved nonfatal MI and downstream testing.

Determinants of functional significance of coronary bifurcation lesions and clinical outcomes after physiology-guided treatment

OBJECTIVES

To determine the rate of functionally significant (fractional flow reserve, FFR ≤ 0.80) coronary bifurcation stenoses that are considered anatomically significant based on angiographic estimation and to define predictors of functional significance of stenoses in main vessel and side branch.

BACKGROUND

To date, the rate of functionally significant stenoses in angiographic significant coronary bifurcation stenoses has not been specifically determined.

METHODS

Patients with significant angiographic bifurcation lesions defined as diameter stenosis >50% in main vessel and/or side branch were included. FFR was performed in main vessel (MV) and side branch (SB) before and after percutaneous coronary intervention (PCI). The protocol was approved by the local ethics committee.

RESULTS

Overall, 171 patients with bifurcation lesions were included. Mean FFR in MV was 0.80 ± 0.01 and 0.84 ± 0.09 in SB. 46% (n = 78) of bifurcation lesions were functionally significant when assessed with FFR. Diameter stenosis in main vessel, lesion length, side branch territory and SYNTAX score (SS) were found as predictors for lesion functional severity (main vessel FFR ≤ 0.80). At the time of follow-up, there were no differences between the treated and deferred group regarding rates of all-cause death, cardio-vascular death, MACEs and POCE.

CONCLUSION

Less than half of all angiographic significant bifurcation lesions were functionally significant when assessed with FFR. There was no difference in clinical outcomes at mean time of three years follow-up in treated and deferred lesion.

Increased deformation of the left ventricle during exercise test measured by global longitudinal strain can rule out significant coronary artery disease in patients with suspected unstable angina pectoris

BACKGROUND

Noninvasive identification of significant coronary artery disease (CAD) in patients with unstable angina pectoris (UAP) is challenging. Exercise stress testing has been used for years in patients with suspected CAD but has low diagnostic accuracy. The use of Global longitudinal strain (GLS) by speckle tracking echocardiography is a highly sensitive and reproducible parameter for detection of myocardial ischemia. Our aim was to study if identification of normal or ischemic myocardium by measurement of GLS immediately after an ordinary bicycle exercise stress testing in patients with suspected UAP could identify or rule out significant CAD.

METHODS

Seventy-eight patients referred for coronary angiography from outpatient clinics and the emergency department with chest pain, inconclusive ECG and normal values of Troponin-T was included. All patients underwent echocardiographic examination at rest and immediately after maximum stress by exercise on a stationary bicycle. Significant CAD was defined by diameter stenosis > 90% by coronary angiography. In patients with coronary stenosis between 50-90%, fractional flow reserve (FFR) was measured and defined abnormal < .80. Analysis of echocardiographic data were performed blinded for angiographic data. Patients were discharged diagnosed with CAD (n = 34) or non-coronary chest pain (NCCP, n = 44).

RESULTS

In patients with NCCP, GLS at rest was -21.1 ± 1.7% and -25.5 ± 2.6% at maximum stress (P < .01). In patients with CAD, GLS at rest was -16.8 ± 4.0% and remained unchanged at maximum stress (-16.6 ± 4.6%, P = .69). In patients with NCCP, LVEF was 56.1% ± 6.0 and increased to 61.8% 5.2, P < .01. In CAD patients, LVEF at rest was 54.7% ± 8.6 and increased to 58.2% ± 9.5 during stress, P = .16. In NCCP patients, Wall Motion Score index decreased .02 ± .07, P = .03 during stress and was without significant changes in patients with CAD. Area under the curve (AUC) for distinguishing CAD for was .97 (.95-1.00), .63 (.49-.76), and .71 (.59-.83) for GLS, LVEF, and WMSi, respectively.

CONCLUSION

In patients with suspected UAP, increased deformation of the left ventricle measured by GLS immediately after exercise stress testing identified normal myocardium without CAD. Reduced LV contractile function by GLS without increase after exercise identified significant CAD.

Comparison of Resting Full-Cycle Ratio and Fractional Flow Reserve in a German Real-World Cohort

Objective: The aim of this study was to evaluate non-hyperemic resting pressure ratios (NHPRs), especially the novel “resting full-cycle ratio” (RFR; lowest pressure distal to the stenosis/aortic pressure during the entire cardiac cycle), compared to the gold standard fractional flow reserve (FFR) in a “real-world” setting.

Methods: The study included patients undergoing coronary pressure wire studies at one German University Hospital. No patients were excluded based on any baseline or procedural characteristics, except for insufficient quality of traces. The diagnostic performance of four NHPRs vs. FFR ≤ 0.80 was tested. Morphological characteristics of stenoses were analyzed by quantitative coronary angiography.

Results: 617 patients with 712 coronary lesions were included. RFR showed a significant correlation with FFR (r = 0.766, p < 0.01). Diagnostic accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of RFR were 78% (95% confidence interval = 75; 81), 72% (65; 78), 81% (77; 84), 63% (57; 69), and 86% (83; 89). Relevant predictors for discordance of RFR ≤ 0.89/FFR > 0.8 were LAD lesions, peripheral artery disease, age, female sex and non-focal stenoses. Predictors for discordance of RFR > 0.89/FFR ≤ 0.8 included non-LCX lesions, percent diameter stenosis and previous percutaneous coronary intervention in the target vessel. RFR and all other NHPRs were highly correlated with each other.

Conclusion: All NHPRs have a similar correlation with the gold standard FFR and may facilitate the acceptance and implementation of physiological assessments of lesion severity. However, we found ~20% discordant results between NHPRs and FFR in our “all-comers” German cohort.

Functional Angioplasty: Definitions, Historical Overview, and Future Perspectives

Percutaneous coronary intervention (PCI) is used to treat obstructive coronary artery disease (CAD). The role of PCI is well defined in acute coronary syndrome, but that for stable CAD remains debatable. Although PCI generally relieves angina in patients with stable CAD, it may not change its prognosis. The extent and severity of CAD are major determinants of prognosis, and complete revascularization (CR) of all ischemia-causing lesions might improve outcomes. Several studies have shown better outcomes with CR than with incomplete revascularization, emphasizing the importance of functional angioplasty. However, different definitions of inducible myocardial ischemia have been used across studies, making their comparison difficult. Various diagnostic tools have been used to estimate the presence, extent, and severity of inducible myocardial ischemia. However, to date, there are no agreed reference standards of inducible myocardial ischemia. The hallmarks of inducible myocardial ischemia such as electrocardiographic changes and regional wall motion abnormalities may be more clinically relevant as the reference standard to define ischemia-causing lesions. In this review, we summarize studies regarding myocardial ischemia, PCI guidance, and possible explanations for similar findings across studies. Also, we provide some insights into the ideal definition of inducible myocardial ischemia and highlight the appropriate PCI strategy.

The Role of Coronary Physiology in Contemporary Percutaneous Coronary Interventions

Invasive assessment of coronary physiology has radically changed the paradigm of myocardial revascularization in patients with coronary artery disease. Despite the prognostic improvement associated with ischemia-driven revascularization strategy, functional assessment of angiographic intermediate epicardial stenosis remains largely underused in clinical practice. Multiple tools have been developed or are under development in order to reduce the invasiveness, cost, and extra procedural time associated with the invasive assessment of coronary physiology. Besides epicardial stenosis, a growing body of evidence highlights the role of coronary microcirculation in regulating coronary flow with consequent pathophysiological and clinical and prognostic implications. Adequate assessment of coronary microcirculation function and integrity has then become another component of the decision-making algorithm for optimal diagnosis and treatment of coronary syndromes. This review aims at providing a comprehensive description of tools and techniques currently available in the catheterization laboratory to obtain a thorough and complete functional assessment of the entire coronary tree (both for the epicardial and microvascular compartments).

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

BACKGROUND AND OBJECTIVES

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT04012281.

[Personalized Therapeutic Concepts in Chronic Coronary Syndromes]

Personalized Therapeutic Concepts in Chronic Coronary Syndromes Abstract. Chronic coronary syndromes (CCS) are related to substantial morbidity and mortality. Myocardial ischemia in CCS is caused by either obstructive or non-obstructive alterations of the coronary arteries, including both morphological and functional changes of epicardial vessels and the coronary microvasculature. Diagnostic algorithms of patients with suspected CCS include non-invasive and invasive imaging and functional testing. Therapeutic management comprises lifestyle changes, optimal medical therapy, and coronary revascularization when indicated. This review summarizes the contemporary management of patients with CCS, focusing on the role of invasive assessment and treatment.

Bifurcation functional significance score as predictor of mortality: a validating study

Considerable progress has been made in the treatment of coronary bifurcation stenosis. Anatomical characteristics of the vessel and lesion, however, fail to give information about the functional significance of the bifurcation stenosis. To the best of our knowledge, there is no study that systematically establishes the baseline functional significance of coronary stenosis and its effect on procedural and clinical outcomes. Patients with significant angiographic bifurcation lesions defined as diameter stenosis > 50% in main vessel and/or side branch were included. FFR was performed in main vessel (MV) and side branch (SB) before and after percutaneous coronary intervention (PCI). 169 patients from Fiesta study (derivation cohort) and 555 patients from prospective bifurcation registry (clinical effect cohort) were analyzed to validate angiographic prediction score (BFSS) used to determine the potentially functional significance of coronary bifurcation stenosis. Bifurcation functional significance score (including the following parameters-SYNTAX ≥ 11, SB/MB BARI score, MV %DS ≥ 55%, main branch (MB) %DS ≥ 65%, lesion length ≥ 25 mm) with a maximum value of 11 was developed. A cut-off value of 6.0 was shown to give the best discriminatory ability-with accuracy 87% (sensitivity 77%, specificity 96%, p < 0.001). There was also a significant difference in all-cause mortality between patients with BFSS ≥ 6.0 vs. BFSS < 6.0-25.5% vs. 18.4%, log-rank p = 0.001 as well as cardiac mortality: BFSS ≥ 6.0 vs. BFSS < 6.0-17.7% vs. 14.5%, log-rank (p = 0.016). The cardiac mortality was significantly lower in patients with smaller absolute SB territory, p = 0.023. An angiographic score (BFSS) with good discriminatory ability to determine the functional significance of coronary bifurcation stenosis was developed. The value for BFSS ≥ 6.0 can be used as a discriminator to define groups with higher risk for all-cause and cardiac mortality. Also, we found that the smaller side branches pose greater mortality risk.

Angiographic quantitative flow ratio-guided coronary intervention (FAVOR III China): a multicentre, randomised, sham-controlled trial

BACKGROUND

Compared with visual angiographic assessment, pressure wire-based physiological measurement more accurately identifies flow-limiting lesions in patients with coronary artery disease. Nonetheless, angiography remains the most widely used method to guide percutaneous coronary intervention (PCI). In FAVOR III China, we aimed to establish whether clinical outcomes might be improved by lesion selection for PCI using the quantitative flow ratio (QFR), a novel angiography-based approach to estimate the fractional flow reserve.

METHODS

FAVOR III China is a multicentre, blinded, randomised, sham-controlled trial done at 26 hospitals in China. Patients aged 18 years or older, with stable or unstable angina pectoris or patients who had a myocardial infarction at least 72 h before screening, who had at least one lesion with a diameter stenosis of 50-90% in a coronary artery with a reference vessel of at least 2·5 mm diameter by visual assessment were eligible. Patients were randomly assigned to a QFR-guided strategy (PCI performed only if QFR ≤0·80) or an angiography-guided strategy (PCI based on standard visual angiographic assessment). Participants and clinical assessors were masked to treatment allocation. The primary endpoint was the 1-year rate of major adverse cardiac events, a composite of death from any cause, myocardial infarction, or ischaemia-driven revascularisation. The primary analysis was done in the intention-to-treat population. The trial was registered with ClinicalTrials.gov (NCT03656848).

FINDINGS

Between Dec 25, 2018, and Jan 19, 2020, 3847 patients were enrolled. After exclusion of 22 patients who elected not to undergo PCI or who were withdrawn by their physicians, 3825 participants were included in the intention-to-treat population (1913 in the QFR-guided group and 1912 in the angiography-guided group). The mean age was 62·7 years (SD 10·1), 2699 (70·6%) were men and 1126 (29·4%) were women, 1295 (33·9%) had diabetes, and 2428 (63·5%) presented with an acute coronary syndrome. The 1-year primary endpoint occurred in 110 (Kaplan-Meier estimated rate 5·8%) participants in the QFR-guided group and in 167 (8·8%) participants in the angiography-guided group (difference, -3·0% [95% CI -4·7 to -1·4]; hazard ratio 0·65 [95% CI 0·51 to 0·83]; p=0·0004), driven by fewer myocardial infarctions and ischaemia-driven revascularisations in the QFR-guided group than in the angiography-guided group.

INTERPRETATION

In FAVOR III China, among patients undergoing PCI, a QFR-guided strategy of lesion selection improved 1-year clinical outcomes compared with standard angiography guidance.

FUNDING

Beijing Municipal Science and Technology Commission, Chinese Academy of Medical Sciences, and the National Clinical Research Centre for Cardiovascular Diseases, Fuwai Hospital.

Clinical Characteristics and Outcomes Among Patients Undergoing High-Risk Percutaneous Coronary Interventions by Single or Multiple Operators: Insights From the Veterans Affairs Clinical Assessment, Reporting, and Tracking Program

Background High-risk percutaneous coronary intervention (HR-PCI) is increasingly common among contemporary patients with coronary artery disease. Experts have advocated for a collaborative 2-operator approach to support intraprocedural decision-making for these complex interventions. The impact of a second operator on patient and procedural outcomes is unknown. Methods and Results Patients who underwent HR-PCI from 2015 to 2018 within the Veterans Affairs Healthcare System were identified. Propensity-matched cohorts were generated to compare the outcomes following HR-PCI performed by a single or multiple (≥2) operators. The primary end point was the 12-month rate of major adverse cardiovascular events. We identified 6672 patients who underwent HR-PCI during the study period; 6211 (93%) were treated by a single operator, and 461 (7%) were treated by multiple operators, with a nonsignificant trend toward increased multioperator procedures over time. A higher proportion of patients treated by multiple operators underwent left main (10% versus 7%, P=0.045) or chronic total occlusion intervention (11% versus 5%, P<0.001). Lead interventionalists participating in multioperator procedures practiced at centers with higher annual HR-PCI volumes (124±71.3 versus 111±69.2; standardized mean difference, 0.197; P<0.001) but otherwise performed a similar number of HR-PCI procedures per year (34.4±35.3 versus 34.7±30.7; standardized mean difference, 0.388; P=0.841) compared with their peers performing single-operator interventions. In a propensity-matched cohort, there was no significant difference in major adverse cardiovascular events (32% versus 30%, P=0.444) between patients who underwent single-operator versus multioperator HR-PCI. Adjusted analyses accounting for site-level variance showed no significant differences in outcomes. Conclusions Patients who underwent multioperator HR-PCI had similar outcomes compared with single-operator procedures. Further studies are needed to determine if the addition of a second operator offers clinical benefits to a subset of HR-PCI patients undergoing left main or chronic total occlusion intervention.

Adoption and patterns of use of invasive physiological assessment of coronary artery disease in a large cohort of 40821 real-world procedures over a 12-year period

INTRODUCTION AND OBJECTIVES

Use of invasive physiological assessment in patients with coronary artery disease varies widely and is perceived to be low. We aimed to examine adoption rates as well as patterns and determinants of use in an unselected population undergoing invasive coronary angiography over a long time frame.

METHODS

We retrospectively determined the per-procedure prevalence of physiological assessment in 40821 coronary cases performed between 2007 and 2018 in two large-volume centers. Adoption was examined according to procedure type and patient- and operator-related variables. Its association with relevant scientific landmarks, such as the release of clinical trial results and practice guidelines, was also assessed.

RESULTS

Overall adoption was low, ranging from 0.6% in patients undergoing invasive coronary angiography due to underlying valve disease, to 6% in the setting of stable coronary artery disease (CAD); it was 3.1% in patients sustaining an acute coronary syndrome. Of scientific landmarks, FAME 1, the long-term results of FAME 2 and the 2014 European myocardial revascularization guidelines were associated with changes in practice. Publication of instantaneous wave-free ratio (iFR) trials had no influence on adoption rates, except for a higher proportion of iFR use. In 42.9% of stable CAD patients undergoing percutaneous coronary intervention there was no objective non-invasive evidence of ischemia, nor was physiological assessment performed. Younger operator age (4.5% vs. 4.0% vs. 0.9% for ages <40, 40-55 and >55 years, respectively; p<0.001) and later time of procedure during the day (2.9% between 6 and 8 p.m. vs. 4.4% at other times) were independent correlates of use of invasive physiology.

CONCLUSIONS

Our study confirms the low use of invasive physiology in routine practice. The availability of resting indices did not increase adoption. Strategies are warranted to promote guideline implementation and to improve patient care and clinical outcomes.

Instantaneous wave-free ratio for guiding treatment of nonculprit lesions in patients with acute coronary syndrome: A retrospective study

BACKGROUND

The aim of this study was to analyze the feasibility of a physiological coronary evaluation with the instantaneous wave-free ratio (iFR) of nonculprit lesions in patients with acute coronary syndrome (ACS) successfully revascularized.

METHODS

A multicenter registry including patients of four high-volume PCI centers with ACS and underwent successful revascularization of the culprit vessel and had other nonculprit lesions that were physiologically evaluated with the iFR between January 2017 and December 2019. The primary endpoint was a composite of cardiac death, nonfatal myocardial infarction, probable or definitive stent thrombosis and new revascularization (MACEs).

RESULTS

A total of 356 patients with 472 nonculprit lesions were included. The mean age was 66 ± 11 years. The clinical presentation was ACS without persistent ST-segment elevation (NSTE-ACS) in 235 patients (66%) and ST-segment elevation myocardial infarction (STEMI) in 121 patients (34%). After a median follow-up period of 21 (14-30) months, the primary endpoint occurred in 32 patients (9%). There were no differences in outcomes regarding clinical presentation (NSTEMI vs. NSTE-ACS, 9.1 vs. 8.9%, p_adj  = 0.570) or iFR induced treatment strategy (patients with all lesions revascularized vs. patients with at least one lesion with an iFR > 0.89 deferred for revascularization, 10.5 vs. 8.4%, p_adj  = 0.476).

CONCLUSIONS

The use of the iFR to guide percutaneous coronary intervention decision making in nonculprit lesions seems to be feasible, with an acceptable percentage of MACEs at the mid-term follow-up. Patients with deferred revascularization of lesions without physiological significance and patients undergoing complete revascularization had a similar risk of MACEs.