Clinical use of intracoronary imaging. Part 2: acute coronary syndromes, ambiguous coronary angiography findings, and guiding interventional decision-making: an expert consensus document of the European Association of Percutaneous Cardiovascular Interventions

Vulnerable plaque features and adverse events in patients with diabetes mellitus: a post hoc analysis of the COMBINE OCT-FFR trial

BACKGROUND

Thin-cap fibroatheroma (TCFA) lesions are associated with a high risk of future major adverse cardiovascular events. However, the impact of other optical coherence tomography-detected vulnerability features (OCT-VFs) and their interplay with TCFA in predicting adverse events remains unknown.

AIMS

We aimed to evaluate the individual as well as the combined prognostic impact of OCT-VFs in predicting the incidence of the lesion-oriented composite endpoint (LOCE) in non-ischaemic lesions in patients with diabetes mellitus (DM).

METHODS

COMBINE OCT-FFR (ClinicalTrials.gov: NCT02989740) was a prospective, double-blind, international, natural history study that included DM patients with ≥1 non-culprit lesions with a fractional flow reserve>0.80 undergoing systematic OCT assessment. OCT-VFs included the following: TCFA, reduced minimal lumen area (r-MLA), healed plaque (HP), and complicated plaque (CP). The primary endpoint, LOCE - a composite of cardiac mortality, target vessel myocardial infarction, or clinically driven target lesion revascularisation up to 5 years - was analysed according to the presence of these OCT-VFs, both individually and in combination.

RESULTS

TCFA, r-MLA, HP and CP were identified in 98 (25.3%), 190 (49.0%), 87 (22.4%), and 116 (29.9%) patients, respectively. The primary endpoint rate increased progressively from 6.3% to 55.6% (hazard ratio 15.2, 95% confidence interval: 4.53-51.0; p<0.001) in patients without OCT-VFs as compared to patients with concomitant HP, r-MLA, CP, and TCFA. The coexistence of TCFA with other OCT-VFs resulted in an increased risk of the LOCE at 5 years.

CONCLUSIONS

In DM patients with non-ischaemic lesions, TCFA was the strongest predictor of future LOCE events. However, lesions that present additional OCT-VFs are associated with a higher risk of adverse events than OCT-detected TCFA alone. Further randomised studies are warranted to confirm these findings and their potential clinical implications.

Intravascular imaging in the diagnosis and management of patients with suspected intracoronary pathologies: A CJC White Paper

Intravascular imaging has become an integral part of the diagnostic and management strategies for intracoronary pathologies. This White Paper summarizes current evidence and its implications on the use of intravascular imaging in interventional cardiology practice. The areas addressed are planning and optimization of percutaneous coronary intervention, management of stent failure, and evaluation of ambiguous coronary lesions and myocardial infarction with non-obstructive coronary disease (MINOCA). Findings are presented following the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system in an expert consensus process involving a diverse Writing group and vetted by a Review group. Expert consensus was achieved around nine statements. Use of intravascular imaging in guiding percutaneous revascularization is supported by high quality evidence, particularly for lesions with increased risk of recurrent events or stent failure. Specific considerations for intravascular imaging guidance of intervention in left main lesions, chronic occlusion lesions as well as patients at high risk of contrast nephropathy are explored. Use of intravascular imaging to identify pathologies associated with stent failure and guide repeat intervention, resolve ambiguities in lesion assessment and establish diagnoses in patients presenting with MINOCA is supported by moderate to low quality evidence. Each topic is accompanied by clinical pointers to aid the practicing interventional cardiologist in implementation of the White paper findings. The findings of this White Paper will help to guide the utilization of intravascular imaging towards those situations in which the balance of efficacy, safety and cost are most optimal.

A novel radiomics-based technique for identifying vulnerable coronary plaques: a follow-up study

BACKGROUND

Previous reports have suggested that coronary computed tomography angiography (CCTA)-based radiomics analysis is a potentially helpful tool for assessing vulnerable plaques. We aimed to investigate whether coronary radiomic analysis of CCTA images could identify vulnerable plaques in patients with stable angina pectoris.

METHODS

This retrospective study included patients initially diagnosed with stable angina pectoris. Patients were randomly divided into either the training or test dataset at an 8 : 2 ratio. Radiomics features were extracted from CCTA images. Radiomics models for predicting vulnerable plaques were developed using the support vector machine (SVM) algorithm. The model performance was assessed using the area under the curve (AUC); the accuracy, sensitivity, and specificity were calculated to compare the diagnostic performance using the two cohorts.

RESULTS

A total of 158 patients were included in the analysis. The SVM radiomics model performed well in predicting vulnerable plaques, with AUC values of 0.977 and 0.875 for the training and test cohorts, respectively. With optimal cutoff values, the radiomics model showed accuracies of 0.91 and 0.882 in the training and test cohorts, respectively.

CONCLUSION

Although further larger population studies are necessary, this novel CCTA radiomics model may identify vulnerable plaques in patients with stable angina pectoris.

Coronary artery calcification: concepts and clinical applications

Vascular calcification is an important hallmark of atherosclerosis. Coronary artery calcification (CAC) implies the presence of coronary artery disease (CAD), irrespective of risk factors or symptoms, is concomitant with the development of advanced atherosclerosis. Coronary thrombosis is the most common clinical end event leading to acute coronary syndrome (ACS). The least common type of pathology associated with thrombosis is the calcified nodule (CN). It usually occurs in elderly patients with severely calcified and tortuous arteries. The prevalence of calcified nodules in patients with ACS may be underestimated due to the lack of easily recognisable diagnostic methods. In this review, the authors will focus on the classification, clinical significance, pathogenesis, and diagnostic evaluation and treatment of CAC to further explore the clinical significance of CN.

Long-term impact of intravascular ultrasound-guidance for percutaneous coronary intervention on unprotected left main. The IMPACTUS-LM, an observational, multicentric study

INTRODUCTION

The potential benefit on long term outcomes of Percutaneous Coronary Intervention (PCI) on Unprotected Left Main (ULM) driven by IntraVascular UltraSound (IVUS) remains to be defined.

METHODS

IMPACTUS LM-PCI is an observational, multicenter study that enrolled consecutive patients with ULM disease undergoing coronary angioplasty in 13 European high-volume centers from January 2002 to December 2015. Major Adverse Cardiovascular Events (MACEs) a composite of cardiovascular (CV) death, target vessel revascularization (TVR) and myocardial infarction (MI) were the primary endpoints, while its single components along with all cause death the secondary ones.

RESULTS

627 patients with ULM disease were enrolled, 213 patients (34%) underwent IVUS-guided PCI while 414 (66%) angioguided PCI. Patients in the two cohorts had similar prevalence of risk factors except for active smoking and clinical presentation. During a median follow-up of 7.5 years, 47 (22%) patients in the IVUS group and 211 (51%) in the angio-guided group underwent the primary endpoint (HR 0.42; 95% CI [0.31-0.58] p < 0.001). After multivariate adjustment, IVUS was significantly associated with a reduced incidence of the primary endpoint (adj HR 0.39; 95% CI [0.23-0.64], p < 0.001), mainly driven by a reduction of TVR (ad HR 0.30, 95% CI [0.15-0.62], p = 0.001) and of all-cause death (adj HR 0.47, 95% CI [0.28-0.82], p = 0.008). IVUS use, age, diabetes, side branch stenosis, DES and creatinine at admission were independent predictors of MACE.

CONCLUSIONS

In patients undergoing ULM PCI, the use of IVUS was associated with a reduced risk at long-term follow-up of MACE, all-cause death and subsequent revascularization.

[Myocardial Infarction with no obstructive coronary arteries: Imaging plays a central role]

Myocardial infarction with non-obstructive coronary lesion (MINOCA) represents a non-negligible percentage of the proportion of myocardial infarctions (≈6%). Moreover, the long-term prognosis is poor, with an annual mortality rate of 2%. This high mortality rate may be explained by the fact that MINOCA represents a heterogeneous group, and the diagnosis of pathology is poorly understood. It is essential to be aware of this clinical presentation, and to follow the different diagnostic strategies, in order to identify the etiological mechanism, and thus set up a suitable treatment. Many tools are available to support diagnosis, notably in the fields of imaging, the principal contributors being coronary angiography, coronary physiology and pharmacological testing, as well as endo-coronary imaging and cardiac MRI. This review will provide an update on the definition, epidemiology, diagnostic strategies and treatment options for patients with MINOCA.

Organized thrombus is a frequent underlying feature in culprit lesion morphology in non-ST-elevation myocardial infarction. A study using optical coherence tomography and magnetic resonance imaging

The concept that the culprit lesion in non-ST segment elevation myocardial infarction (NSTEMI) is caused by sudden plaque rupture with acute thrombus formation has recently been challenged. While angiography is an old gold-standard for culprit identification it merely visualizes the lumen contour. Optical coherence tomography (OCT) provides a detailed view of culprit features. Combined with myocardial edema on cardiac magnetic resonance (CMR), indicating acute ischemia and thus culprit location, we aimed to characterize culprit lesions using OCT. Patients with NSTEMI referred for angiography were prospectively enrolled. OCT was performed on angiographic stenoses ≥50% and on operator-suspected culprit lesions. Hierarchical OCT-culprit identifiers were defined in case of multiple unstable lesions, including OCT-defined thrombus age. An OCT-based definition of an organizing thrombus as corresponding to histological early healing stage was introduced. Lesions were classified as OCT-culprit or non-culprit, and characteristics compared. CMR was performed in a subset of patients. We included 65 patients with 97 lesions, of which 49 patients (75%) had 53 (54%) OCT-culprit lesions. The most common OCT-culprit identifiers were the presence of acute (66%) and organizing thrombus (19%). Plaque rupture was visible in 45% of OCT-culprit lesions. CMR performed in 38 patients revealed myocardial oedema in the corresponding territories of 67% of acute thrombi and 50% of organizing thrombi. A culprit lesion was identified by OCT in 75% patients with NSTEMI. Acute thrombus was the most frequent feature followed by organizing thrombus. Applying specific OCT-criteria to identify the culprit could prove valuable in ambiguous cases.

The diagnosis and treatment of women with recurrent cardiac ischemia and normal coronary arteries

Cardiac disease is the leading cause of death in women. Among women with recurrent chest pain, abnormal electrocardiograms, and/or stress tests who undergo coronary angiography, as many as 50% have normal or <50% coronary artery obstructive disease. Pharmacologic stress assessment of coronary artery flow reserve in these women frequently demonstrates an inability to increase blood flow to >2.5 times normal flow. Contributory factors include abnormal epicardial or microvascular reactivity, microvascular remodeling or rarefaction, autonomic dysfunction, or coronary plaque rupture/erosion. Assessment is necessary of serum biomarkers and coronary artery flow reserve, fractional flow reserve, microvascular resistance, and epicardial/microvascular spasm. Aggressive treatment of women with positive tests is necessary because these women have an increased incidence of recurrent chest pain, repeated hospitalizations and coronary angiograms, and cardiac death.

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).

Effect of ticagrelor versus clopidogrel after implantation of drug-eluting stents guided by either intravascular ultrasound or angiography in patients with acute coronary syndrome-propensity score matching analysis

BACKGROUND

The effect of different dual antiplatelet therapies on thrombotic events on the background of intravascular ultrasound (IVUS) guidance is unclear. We investigated whether ticagrelor can provide any additional benefit to clopidogrel in reducing thrombotic events in acute coronary syndrome (ACS) treated with drug- eluting stent (DES), when guided by IVUS or not.

METHODS

A total of 5,666 ACS patients who underwent DES implantation and who were discharged on dual antiplatelet therapy were enrolled and grouped according to the use of IVUS or not. Each group was subdivided into two subgroups according to the type of P2Y12 inhibitor used after discharge. Propensity score matching (PSM) was used between the IVUS and no-IVUS groups. Covariate adjustment of Cox proportional hazards model was used between the ticagrelor and clopidogrel groups. Thrombotic event at 12 months was compared in groups separately.

RESULTS

After PSM, 12-month follow-up data were available for 1,174 patients. Major adverse cardiac events (MACE) were less frequent in the IVUS-guided group (2.2% vs. 4.3%, P = 0.081) with a trend toward statistical significance. Comparison of antiplatelet regimens revealed significantly fewer major adverse cardiac and cerebrovascular events (MACCE) with ticagrelor in the entire PSM cohort and angiography-guided subgroup (2.9% vs. 5.7%, P = 0.035; 3.1% vs. 6.4%, P = 0.020, respectively). Among patients in the IVUS-guided group the outcome was comparable (2.5% vs. 4.4%, P = 0.312). Ticagrelor was associated with increasing bleeding incidence in the entire PSM cohort (1.3% vs. 3.3%, P = 0.030), mainly due to Bleeding Academic Research Consortium type 2 bleeding (0.7% vs. 2.6%, P = 0.010). The results were consistent after covariate adjustment of Cox proportional hazards model.

CONCLUSION

The comparison of ischemic benefit between ticagrelor and clopidogrel was similar in patients receiving IVUS guidance during stent implantation, probably due to the precise implantation of IVUS. Multicenter, randomized studies should be performed to validate this conclusion.

Two-year results from Onyx ONE clear in patients with high bleeding risk on one-month DAPT with and without intracoronary imaging

BACKGROUND

Patients with high bleeding risk (HBR) are often treated with abbreviated dual antiplatelet therapy (DAPT) after percutaneous coronary intervention (PCI) to reduce bleeding risk, however this strategy is associated with an increase in ischemic events, especially if the acute PCI result is suboptimal. We compared clinical outcomes among patients with HBR treated with 1-month DAPT who underwent intravascular ultrasound (IVUS)- or optical coherence tomography (OCT)-guided PCI versus those who underwent angiography-guided PCI without intravascular imaging.

METHODS

The Onyx ONE Clear study includes patients with HBR from the Onyx ONE US/Japan and Onyx ONE randomized studies who were treated with the Resolute Onyx zotarolimus-eluting stent. The primary endpoint was the composite of cardiac death (CD) or myocardial infarction (MI) between 1 month and 2 years after PCI. Propensity-score adjustments and matching were performed for differences in baseline and procedural characteristics between groups.

RESULTS

Among the 1507 patients in Onyx ONE Clear, 271 (18.0 %) had IVUS or OCT used during PCI (Imaging-guided group) and 1236 (82.0 %) underwent Angiography-guided PCI (Angio-guided group). Imaging-guided patients were less likely to present with atrial fibrillation, acute coronary syndrome, and left ventricle ejection fraction ≤35 %. Conversely, Imaging-guided patients were more likely to have complex (ACC/AHA type B2/C), longer, and heavily calcified lesions. Between 1 month and 2 years, the composite rate of CD or MI was similar between Imaging-guided and Angio-guided patients (9.9 % vs. 12.4 %, P = 0.33). There was also no difference between groups after adjustment; (P = 0.56). However, CD was significantly lower among Imaging-guided patients (2.7 % vs. 6.1 %, P = 0.048). There were no between-group differences in MI or stent thrombosis. Propensity score matching results were similar.

CONCLUSION

Despite higher lesion complexity, using intravascular imaging guidance for PCI between 1-month and 2-years follow-up had comparable outcomes with angiographic guidance alone in patients with HBR treated with 1-month DAPT. (ClinicalTrials.gov: Identifier: NCT03647475 and NCT03344653).

NON-STANDARD ABBREVIATIONS AND ACRONYMS

BARC: Bleeding Academic Research Consortium; DAPT: dual antiplatelet therapy; DES: drug-eluting stent; HBR: high bleeding risk; IVUS: intravascular ultrasound; OCT: optical coherence tomography; SAPT: single antiplatelet therapy.

CVIT 2023 clinical expert consensus document on intravascular ultrasound

Intravascular ultrasound (IVUS) provides precise anatomic information in coronary arteries including quantitative measurements and morphological assessment. To standardize the IVUS analysis in the current era, this updated expert consensus document summarizes the methods of measurements and assessment of IVUS images and the clinical evidence of IVUS use in percutaneous coronary intervention.

Pathophysiology and diagnostic pathway of myocardial infarction with non-obstructive coronary arteries

Myocardial infarction with non-obstructive coronary arteries (MINOCA) is a heterogeneous and diverse disease entity, which accounts for about 6 % of all acute myocardial infarction (AMI) cases. In patients with chest pain and acute myocardial injury detected by a highly sensitive troponin assay, the absence of epicardial coronary stenosis of 50 % or greater on angiography leads to the working diagnosis of MINOCA. The updated JCS/CVIT/JCC 2023 Guideline described MINOCA as a new disease concept and recommended a multimodality approach to uncovering the underlying causes of MINOCA. Cardiac magnetic resonance (CMR) is useful in not only making a definite diagnosis of MINOCA, but also excluding non-ischemic causes that mimic AMI such as takotsubo cardiomyopathy and myocarditis. Meanwhile, intracoronary imaging, particularly optical coherence tomography (OCT), enables us to evaluate precisely intracoronary morphological alterations including plaque disruption and spontaneous coronary artery dissection which are not revealed by angiographic findings alone. Recent studies have shown that an initial workup with the combination of CMR and OCT could provide a definite diagnosis in a significant percentage of patients suspected of MINOCA. Consecutively, patients with inconclusive results of a series of CMR and OCT implementation are eligible for assessing the potential for coronary functional abnormalities or blood coagulopathy as another factor involved in the development of MINOCA. Although uncovering the pathogenesis of MINOCA might be essential for establishing an individualized treatment approach, significant knowledge gaps in terms of secondary prevention strategies for MINOCA focusing on the improvement of long-term prognosis remain to be overcome. In this review, we summarize our current understanding of MINOCA and highlight contemporary diagnostic approaches for patients with suspected MINOCA.

Evidence-based Management of Left Main Coronary Artery Disease

Left main coronary artery disease (LMCAD) is associated with high morbidity and mortality due to the large myocardial mass at risk. Although medical treatment may be an option in selected low-risk patients, revascularisation is recommended to improve survival in the majority of patients presenting with a significant left main stenosis. In the past decade, multiple randomised clinical trials and meta-analyses have compared coronary artery bypass grafting surgery (CABG) versus percutaneous coronary intervention (PCI), finding controversial results. The strategy for LMCAD revascularisation is still challenging. Coronary anatomy complexity, clinical features and patient preferences are key elements to be considered by the heart team. The current guidelines define CABG as standard therapy, but the continuous improvements in PCI techniques, the use of intracoronary imaging and functional assessment make PCI a feasible alternative in selected patients, particularly in those with comorbidities and contraindications to CABG. This review analyses the most important studies comparing CABG versus PCI in patients with LMCAD.

Effect of PCSK9 antibodies on coronary plaque regression and stabilization derived from intravascular imaging in patients with coronary artery disease: A meta-analysis

BACKGROUND

Despite extensive evidence demonstrating the beneficial effects of the additional PCSK9 antibodies with high-density statins treatment on cardiovascular clinical outcomes, the potent causes underlying these effects remain elusive. This meta-analysis aimed at exploring the underlying causes to assess the effect of PCSK9 antibodies on the regression and stabilization of coronary plaque derived from intravascular imaging in statin-treated patients with coronary artery disease (CAD).

METHODS

PubMed, Embase, and Cochrane Library were searched from inception to February 1, 2023, for randomized controlled trials (RCTs), nonrandomized studies without language restrictions if they described the association between PCSK9 antibodies with coronary plaque regression and stabilization evaluated by intravascular imaging in statin-treated patients with CAD. Meta-analyses were performed for mean difference (MD) and odds ratio (OR) using a random-effects model. This study followed the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guideline.

RESULTS

A total of 9 studies (7 RCTs and 2 non-RCTs) with 2290 CAD patients were identified and included. Among statin-treated CAD patients, the addition use of PCSK9 antibodies was associated with IVUS-derived percent atheroma volume (PAV) (4 studies with 1875 participants; MD, -1.26; 95% CI, -1.51 to -1.00; P < 0.01), total atheroma volume (TAV) (4 studies with 1875 participants; MD, -7.23; 95% CI, -11.28 to -3.18; P < 0.01), incidence of PAV regression (4 studies with 1875 participants; OR, 2.24; 95% CI, 1.81 to 2.77; P < 0.01) and incidence of TAV regression (3 studies with 1256 participants; OR, 1.66; 95% CI, 1.33 to 2.09; P < 0.01) in Caucasians instead of Asians from multiple countries; OCT-derived minimum fibrous cap thickness (FCT) (6 studies with 841 participants; MD, 25.16; 95% CI, 14.06 to 36.27; P < 0.01), incidence of thin-capped fibroatheroma (TCFA) regression (2 studies with 222 participants; OR, 2.56; 95% CI, 1.42 to 4.61; P < 0.01) and maximum lipid arc (4 studies with 280 participants; MD, -14.96; 95% CI, -22.10 to -7.83; P < 0.01) in Asians and Caucasians without races restrictions.

CONCLUSIONS

PCSK9 antibodies resulted in significantly greater coronary plaque regression and stabilization in statin-treated CAD patients, mostly Caucasians from multiple countries. Further studies are needed to assess the effect for Asian patients.

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.

Acute Coronary Syndromes in Women: A Narrative Review of Sex-Specific Characteristics

Acute coronary syndromes (ACSs) encompass a spectrum of life-threatening cardiovascular conditions, including unstable angina (UA) and myocardial infarction. While significant progress has been made in the understanding and management of ACS over the years, it has become increasingly evident that sex-based differences play a pivotal role in the pathophysiology, presentation, and outcomes of these conditions. Despite this recognition, the majority of clinical research in the field has historically focused on male populations, leading to a significant knowledge gap in understanding the unique aspects of ACS in women. This review article aims to comprehensively explore and synthesize the current body of literature concerning the sex-specific characteristics of ACS, shedding light on the epidemiology, risk factors, clinical presentation, diagnostic challenges, treatment strategies, and prognosis in women. By elucidating the distinct aspects of ACS in women, this review intends to foster greater awareness and improved clinical management, ultimately contributing to enhanced cardiovascular care for female patients.

Invasive imaging modalities in a spontaneous coronary artery dissection: when "believing is seeing"

Spontaneous coronary artery dissection (SCAD) is a rare but increasingly recognized cause of acute coronary syndrome (ACS) with recent advancements in cardiac imaging facilitating its identification. However, SCAD is still often misdiagnosed due to the absence of angiographic hallmarks in a significant number of cases, highlighting the importance of meticulous interpretation of angiographic findings and, when necessary, additional usage of intravascular imaging to verify changes in arterial wall integrity and identify specific pathoanatomical features associated with SCAD. Accurate diagnosis of SCAD is crucial, as the optimal management strategies for patients with SCAD differ from those with atherosclerotic coronary disease. Current treatment strategies favor a conservative approach, wherein intervention is reserved for cases with persistent ischemia, patients with high-risk coronary anatomy, or patients with hemodynamic instability. In this paper, we provide a preview of invasive imaging modalities and classical angiographic and intravascular imaging hallmarks that may facilitate proper SCAD diagnosis.

Effect of Intensive Lipid-Lowering Therapy on Coronary Plaque Stabilization Derived from Optical Coherence Tomography: a Meta-analysis and Meta-regression

PURPOSE

The definitive impacts of intensive lipid-lowering therapy (LLT) on plaque stabilization and the relationship between the key markers during LLT and plaque stability remain unquestioned. Thus, these meta-analysis and meta-regression intend to holistically evaluate the influence exerted by rigorous LLT on the minimum fibrous cap thickness (FCT) and maximum lipid arc as discerned through optical coherence tomography (OCT). This study further scrutinizes the correlation of this impact with variations in high-sensitivity C-reactive protein (hs-CRP), low-density lipoprotein cholesterol (LDL-C), or additional parameters within patients diagnosed with coronary artery disease (CAD).

METHODS

Comprehensive searches were conducted on platforms including PubMed, Embase, and the Cochrane Library for randomized controlled trials (RCTs) published until June 1, 2023. The search was language agnostic and targeted RCTs elaborating on the correlation between high-intensity statin therapy or statins used concomitantly with other lipid-lowering medications and the minimum FCT and maximum lipid arc as assessed by OCT. The meta-analyses were executed employing a standard mean difference (SMD) algorithm with random-effects on continuous variables. These methodologies align with the Preferred Reporting Items for Systematic and Meta-analysis (PRISMA) guidelines.

RESULTS

A spectrum of 12 RCTs engaging 972 patients were identified and mobilized for these analyses. Meta-analysis outcomes depicted a conspicuous correlation between intensive LLT and an enhanced minimum FCT (12 studies with 972 participants; SMD, 0.87; 95% CI, 0.54 to 1.21; P < 0.01), reduced maximum lipid arc (9 studies with 564 participants; SMD, -0.43; 95% CI, -0.58 to -0.29; P < 0.01). Meta-regression analysis has determined an association of elevated minimum FCT with decreased LDL-C (β, -0.0157; 95% CI, -0.0292 to -0.0023; P = 0.025), total cholesterol (TC) (β, -0.0154; 95% CI, -0.0303 to -0.0005; P = 0.044), and apolipoprotein B (ApoB) (β, -0.0209; 95% CI, -0.0361 to -0.0057; P = 0.022). However, no significant association was discerned relative to variations in hs-CRP/CRP (β, -0.1518; 95% CI, -1.3766 to -1.0730; P = 0.772), triglyceride (TG) (β, -0.0030; 95% CI, -0.0258 to -0.0318; P = 0.822), and high-density lipoprotein cholesterol (HDL-C) (β, 0.0313; 95% CI, -0.0965 to 0.1590; P = 0.608). Subsequent subgroup meta-analysis demonstrated that high-intensity statin therapy (5 studies with 204 participants; SMD, 1.03; 95% CI, 0.67 to 1.39; P < 0.01), as well as a combinative approach including PCSK9 antibodies and statins (3 studies with 522 participants; SMD, 1.17; 95% CI, 0.62 to 1.73; P < 0.01) contributed to an increase in minimum FCT. Parallelly, high-intensity statin therapy (4 studies with 183 participants; SMD, -0.42; 95% CI, -0.65 to -0.19; P < 0.01) or the combined application of PCSK9 antibodies and statins (2 studies with 222 participants; SMD, -0.98; 95% CI, -1.26 to -0.70; P < 0.01) was evidenced to decrease the maximum lipid arc.

CONCLUSIONS

Intensive LLT, mainly high-intensity statin therapy and combined PCSK9 antibody with statin, has a beneficial effect on coronary plaque stabilization derived from OCT in patients with CAD. Coronary plaque stabilization is primarily due to lipid-lowering effect, not anti-inflammatory effect. Moreover, the lipid-lowering effect has nothing to do with the changes in HDL-C and TG, but is mainly related to the reduction of LDL-C, TC, and ApoB.

Clinical quantitative coronary artery stenosis and coronary atherosclerosis imaging: a Consensus Statement from the Quantitative Cardiovascular Imaging Study Group

The detection and characterization of coronary artery stenosis and atherosclerosis using imaging tools are key for clinical decision-making in patients with known or suspected coronary artery disease. In this regard, imaging-based quantification can be improved by choosing the most appropriate imaging modality for diagnosis, treatment and procedural planning. In this Consensus Statement, we provide clinical consensus recommendations on the optimal use of different imaging techniques in various patient populations and describe the advances in imaging technology. Clinical consensus recommendations on the appropriateness of each imaging technique for direct coronary artery visualization were derived through a three-step, real-time Delphi process that took place before, during and after the Second International Quantitative Cardiovascular Imaging Meeting in September 2022. According to the Delphi survey answers, CT is the method of choice to rule out obstructive stenosis in patients with an intermediate pre-test probability of coronary artery disease and enables quantitative assessment of coronary plaque with respect to dimensions, composition, location and related risk of future cardiovascular events, whereas MRI facilitates the visualization of coronary plaque and can be used in experienced centres as a radiation-free, second-line option for non-invasive coronary angiography. PET has the greatest potential for quantifying inflammation in coronary plaque but SPECT currently has a limited role in clinical coronary artery stenosis and atherosclerosis imaging. Invasive coronary angiography is the reference standard for stenosis assessment but cannot characterize coronary plaques. Finally, intravascular ultrasonography and optical coherence tomography are the most important invasive imaging modalities for the identification of plaques at high risk of rupture. The recommendations made in this Consensus Statement will help clinicians to choose the most appropriate imaging modality on the basis of the specific clinical scenario, individual patient characteristics and the availability of each imaging modality.

Diagnostic Puzzles and Cause-Targeted Treatment Strategies in Myocardial Infarction with Non-Obstructive Coronary Arteries: An Updated Review

Myocardial infarction with nonobstructive coronary arteries (MINOCA) is a distinct subtype of myocardial infarction (MI), occurring in about 8-10% of spontaneous MI cases referred for coronary angiography. Unlike MI with obstructive coronary artery disease, MINOCA's pathogenesis is more intricate and heterogeneous, involving mechanisms such as coronary thromboembolism, coronary vasospasm, microvascular dysfunction, dissection, or plaque rupture. Diagnosing MINOCA presents challenges and includes invasive and non-invasive strategies aiming to differentiate it from alternative diagnoses and confirm the criteria of elevated cardiac biomarkers, non-obstructive coronary arteries, and the absence of alternate explanations for the acute presentation. Tailored management strategies for MINOCA hinge on identifying the underlying cause of the infarction, necessitating systematic diagnostic approaches. Furthermore, determining the optimal post-MINOCA medication regimen remains uncertain. This review aims to comprehensively address the current state of knowledge, encompassing diagnostic and therapeutic approaches, in the context of MINOCA while also highlighting the evolving landscape and future directions for advancing our understanding and management of this intricate myocardial infarction subtype.

The Usefulness of Intracoronary Imaging in Patients with ST-Segment Elevation Myocardial Infarction

Intracoronary imaging (ICI) modalities, namely intravascular ultrasound (IVUS) and optical coherence tomography (OCT), have shown to be able to reduce major adverse cardiovascular events in patients undergoing percutaneous coronary intervention (PCI). Nevertheless, patients with ST-segment elevation myocardial infarction (STEMI) have been practically excluded from contemporary large randomized controlled trials. The available data are limited and derive mostly from observational studies. Nevertheless, contemporary studies are in favor of ICI utilization in patients who undergo primary PCI. Regarding technical aspects of PCI, ICI has been associated with the implantation of larger stent diameters, higher balloon inflations and lower residual in-stent stenosis post-PCI. OCT, although used significantly less often than IVUS, is a useful tool in the context of myocardial infarction without obstructive coronary artery disease since, due to its high spatial resolution, it can identify the underlying mechanism of STEMI, and, thus, guide therapy. Stent thrombosis (ST) is a rare, albeit a potential lethal, complication that is expressed clinically as STEMI in the vast majority of cases. Use of ICI is encouraged with current guidelines in order to discriminate the mechanism of ST among stent malapposition, underexpansion, uncovered stent struts, edge dissections, ruptured neoatherosclerotic lesions and coronary evaginations. Finally, ICI has been proposed as a tool to facilitate stent deferring during primary PCI based on culprit lesion characteristics.

Feasibility and safety of non-contrast optical coherence tomography imaging using hydroxyethyl starch in coronary arteries

Intracoronary optical coherence tomography (OCT) requires injection of flushing media for image acquisition. Alternative flushing media needs to be investigated to reduce the risk of contrast-induced renal dysfunction. We investigated the feasibility and safety of pentastarch (hydroxyethyl starch) for clinical OCT imaging. We prospectively enrolled 43 patients with 70 coronary lesions (46-stented; 24-native). Total 81 OCT pullback pairs were obtained by manual injection of iodine contrast, followed by pentastarch. Each pullback was assessed frame-by-frame using an automated customized lumen contour/stent strut segmentation algorithm. Paired images were compared for the clear image segments (CIS), blood-flushing capability, and quantitative morphometric measurements. Overall image quality, as assessed by the proportion of CIS, was comparable between the contrast- and pentastarch-flushed images (97.1% vs. 96.5%; p = 0.160). The pixel-based blood-flushing capability was similar between the groups (0.951 [0.947-0.953] vs. 0.950 [0.948-0.952], p = 0.125). Quantitative two- and three-dimensional morphometric measurements of the paired images correlated well (p < 0.001) with excellent inter-measurement variability. All patients safely underwent OCT imaging using pentastarch without resulting in clinically relevant complications or renal deterioration. Non-contrast OCT imaging using pentastarch is clinically safe and technically feasible with excellent image quality and could be a promising alternative strategy for patients at high risk of renal impairment.

Effectiveness and safety of optical coherence tomography-guided PCI in Indian patients with complex lesions: A multicenter, prospective registry

BACKGROUND

Optical coherence tomography (OCT) is reported to be a feasible and safe imaging modality for the guidance of percutaneous coronary intervention (PCI) of complex lesions.

METHODS

This multicenter, prospective registry assessed the minimum stent area (MSA) achieved under OCT guidance. A performance goal of 24% improvement in MSA over and above the recommendation set by the European Association of Percutaneous Cardiovascular Interventions Consensus 2018 (4.5 mm2 MSA for non-left main and 3.5 mm2 for small vessels). The incidence of contrast-induced nephropathy was also assessed. Core lab analysis was conducted.

RESULTS

Five hundred patients (average age: 59.4 ± 10.1 years; 83% males) with unstable angina (36.8%), NSTEMI (26.4%), and STEMI (22%) were enrolled. The primary endpoint was achieved in 93% of lesions with stent diameter ≥2.75 mm (average MSA: 6.44 mm2) and 87% of lesions with stent diameter ≤2.5 mm (average MSA: 4.56 mm2). The average MSA (with expansion ≥80% cutoff) was 6.63 mm2 and 4.74 mm2 with a stent diameter ≥2.75 mm and ≤2.5 mm, respectively. According to the core lab analysis, the average MSA achieved with a stent diameter ≥2.75 mm and ≤2.5 mm was 6.23 mm2 and 3.95 mm2, respectively (with expansion ≥80% cutoff). Clinically significant serum creatinine was noted in two patients (0.45%). Major adverse cardiac events at 1 year were noted in 1.2% (n = 6) of the patients; all were cardiac deaths.

CONCLUSION

PCI under OCT guidance improves procedural and long-term clinical outcomes in patients with complex lesions not just in a controlled trial environment but also in routine clinical practice.

Multimodality OCT, IVUS and FFR evaluation of coronary intermediate grade lesions in women vs. men

Background

The pathophysiology of atherosclerotic plaque formation and its vulnerability seem to differ between genders due to contrasting risk profiles and sex hormones, however this process is still insufficiently understood. The aim of the study was to compare the differences between sexes regarding the optical coherence tomography (OCT), intravascular ultrasound (IVUS) and fractional flow reserve (FFR)-derived coronary plaque indices.

Methods

In this single-center multimodality imaging study patients with intermediate grade coronary stenoses identified in coronary angiogram (CAG) were evaluated using OCT, IVUS and FFR. Stenoses were considered significant when the FFR value was ≤0.8. Minimal lumen area (MLA), was analyzed by OCT in addition to plaque stratification into fibrotic, calcific, lipidic and thin-cap fibroatheroma (TCFA). IVUS was used for evaluation of lumen-, plaque- and vessel volume, as well as plaque burden.

Results

A total of 112 patients (88 men and 24 women) with chronic coronary syndromes (CCS), who underwent CAG were enrolled. No significant differences in baseline characteristics were present between the study groups. The mean FFR was 0.76 (0.73-0.86) in women and 0.78 ± 0.12 in men (p = 0.695). OCT evaluation showed a higher prevalence of calcific plaques among women than men p = 0.002 whereas lipid plaques were more frequent in men (p = 0.04). No significant differences regarding minimal lumen diameter and minimal lumen area were found between the sexes. In IVUS analysis women presented with significantly smaller vessel area, plaque area, plaque volume, vessel volume (11.1 ± 3.3 mm² vs. 15.0 ± 4.6 mm² p = 0.001, 6.04 ± 1.7 mm² vs. 9.24 ± 2.89 mm² p < 0.001, 59.8 ± 35.2 mm³ vs. 96.3 (52.5-159.1) mm³ p = 0.005, 106.9 ± 59.8 mm³ vs. 153.3 (103-253.4) mm³ p = 0.015 respectively). At MLA site plaque burden was significantly greater for men than women (61.50 ± 7.7% vs. 55.5 ± 8.0% p = 0.005). Survival did not differ significantly between women and men (94.6 ± 41.9 months and 103.51 ± 36.7 months respectively; p = 0.187).

Conclusion

The presented study did not demonstrate significant differences in FFR values between women and men, yet a higher prevalence of calcific plaques by OCT and lower plaque burden at the MLA site by IVUS was found in women vs. men.

Utility of optical coherence tomography in acute coronary syndromes

Studies utilizing intravascular imaging have replicated the findings of histopathological studies, identifying the most common substrates for acute coronary syndromes (ACS) as plaque rupture, erosion, and calcified nodule, with spontaneous coronary artery dissection, coronary artery spasm, and coronary embolism constituting the less common etiologies. The purpose of this review is to summarize the data from clinical studies that have used high-resolution intravascular optical coherence tomography (OCT) to assess culprit plaque morphology in ACS. In addition, we discuss the utility of intravascular OCT for effective treatment of patients presenting with ACS, including the possibility of culprit lesion-based treatment by percutaneous coronary intervention.

Myocardial infarction with nonobstructive coronary arteries: from pathophysiology to therapeutic strategies

Myocardial infarction with nonobstructive coronary arteries (MINOCA) is a heterogeneous group of clinical entities characterized by clinical evidence of acute myocardial infarction (AMI) with normal or near-normal coronary arteries on coronary angiography (stenosis < 50%) and without an over the alternative diagnosis for the acute presentation. Its prevalence ranges from 6% to 11% among all patients with AMI, with a predominance of young, nonwhite females with fewer traditional risks than those with an obstructive coronary artery disease (MI-CAD). MINOCA can be due to either epicardial causes such as rupture or fissuring of unstable nonobstructive atherosclerotic plaque, coronary artery spasm, spontaneous coronary dissection and cardioembolism in-situ or microvascular causes. Besides, also type-2 AMI due to supply-demand mismatch and Takotsubo syndrome must be considered as a possible MINOCA cause. Because of the complex etiology and a limited amount of evidence, there is still some confusion around the management and treatment of these patients. Therefore, the key focus of this condition is to identify the underlying individual mechanisms to achieve patient-specific treatments. Clinical history, electrocardiogram, echocardiography, and coronary angiography represent the first-level diagnostic investigations, but coronary imaging with intravascular ultrasound and optical coherent tomography, coronary physiology testing, and cardiac magnetic resonance imaging offer additional information to understand the underlying cause of MINOCA. Although the prognosis is slightly better compared with MI-CAD patients, MINOCA is not always benign and depends on the etiopathology. This review analyzes all possible pathophysiological mechanisms that could lead to MINOCA and provides the most specific and appropriate therapeutic approach in each scenario.

Optical coherence tomography-derived lipid core burden index and clinical outcomes: results from the CLIMA registry

AIMS

The aim of this study was to assess the morphological characteristics and prognostic implications of the optical coherence tomography (OCT)-derived lipid core burden index (LCBI).

METHODS AND RESULTS

OCT-LCBI was assessed in 1003 patients with 1-year follow-up from the CLIMA multicentre registry using a validated software able to automatically obtain a maximum OCT-LCBI in 4 mm (maxOCT-LCBI4mm). Primary composite clinical endpoint included cardiac death, myocardial infarction, and target-vessel revascularization. A secondary analysis using clinical outcomes of CLIMA study was performed. Patients with a maxOCT-LCBI4mm ≥ 400 showed higher prevalence of fibrous cap thickness (FCT) <75 μm [odds ratio (OR) 1.43, 95% confidence interval (CI) 1.03-1.99; P = 0.034], lipid pool arc >180° (OR 3.93, 95%CI 2.97-5.21; P < 0.001), minimum lumen area <3.5 mm2 (OR 1.5, 95%CI 1.16-1.94; P = 0.002), macrophage infiltration (OR 2.38, 95%CI 1.81-3.13; P < 0.001), and intra-plaque intimal vasculature (OR 1.34, 95%CI 1.05-1.72; P = 0.021). A maxOCT-LCBI4mm ≥400 predicted the primary endpoint [adjusted hazard ratio (HR) 1.86, 95%CI 1.1-3.2; P = 0.019] as well as the CLIMA endpoint (HR 2.56, 95%CI 1.24-5.29; P = 0.011). Patients with high lipid content and thin FCT < 75 µm were at higher risk for adverse events (HR 4.88, 95%CI 2.44-9.72; P < 0.001).

CONCLUSIONS

A high maxOCT-LCBI4mm was related to poor outcome and vulnerable plaque features. This study represents a step further in the automated assessment of the coronary plaque risk profile.

A Coronary CT Angiography Radiomics Model to Identify Vulnerable Plaque and Predict Cardiovascular Events

Background A noninvasive coronary CT angiography (CCTA)-based radiomics technique may facilitate the identification of vulnerable plaques and patients at risk for future adverse events. Purpose To assess whether a CCTA-based radiomic signature (RS) of vulnerable plaques defined with intravascular US was associated with increased risk for future major adverse cardiac events (MACE). Materials and Methods In a retrospective study, an RS of vulnerable plaques was developed and validated using intravascular US as the reference standard. The RS development data set included patients first undergoing CCTA and then intravascular US within 3 months between June 2013 and December 2020 at one tertiary hospital. The development set was randomly assigned to training and validation sets at a 7:3 ratio. Diagnostic performance was assessed internally and externally from three tertiary hospitals using the area under the curve (AUC). The prognostic value of the RS for predicting MACE was evaluated in a prospective cohort with suspected coronary artery disease between April 2018 and March 2019. Multivariable Cox regression analysis was used to evaluate the RS and conventional anatomic plaque features (eg, segment involvement score) for predicting MACE. Results The RS development data set included 419 lesions from 225 patients (mean age, 64 years ± 10 [SD]; 68 men), while the prognostic cohort included 1020 lesions from 708 patients (mean age, 62 years ± 11; 498 men). Sixteen radiomic features, including two shape features and 14 textural features, were selected to build the RS. The RS yielded a moderate to good AUC in the training, validation, internal, and external test sets (AUC = 0.81, 0.75, 0.80, and 0.77, respectively). A high RS (≥1.07) was independently associated with MACE over a median 3-year follow-up (hazard ratio, 2.01; P = .005). Conclusion A coronary CT angiography-derived radiomic signature of coronary plaque enabled the detection of vulnerable plaques that were associated with increased risk for future adverse cardiac outcomes. © RSNA, 2023 Supplemental material is available for this article. See also the editorial by De Cecco and van Assen in this issue.

Intravascular Imaging During Percutaneous Coronary Intervention: JACC State-of-the-Art Review

Coronary angiography has historically served as the gold standard for diagnosis of coronary artery disease and guidance of percutaneous coronary intervention (PCI). Adjunctive use of contemporary intravascular imaging (IVI) technologies has emerged as a complement to conventional angiography-to further characterize plaque morphology and optimize the performance of PCI. IVI has utility for preintervention lesion and vessel assessment, periprocedural guidance of lesion preparation and stent deployment, and postintervention assessment of optimal endpoints and exclusion of complications. The role of IVI in reducing major adverse cardiac events in complex lesion subsets is emerging, and further studies evaluating broader use are underway or in development. This paper provides an overview of currently available IVI technologies, reviews data supporting their utilization for PCI guidance and optimization across a variety of lesion subsets, proposes best practices, and advocates for broader use of these technologies as a part of contemporary practice.

Optical coherence tomography and coronary revascularization: from indication to procedural optimization

Angiography alone is the most commonly used imaging modality for guidance of percutaneous coronary interventions. Angiography is limited, however, by several factors, including that it only portrays a low resolution, two-dimensional outline of the lumen and does not inform on plaque composition and functional stenosis severity. Optical coherence tomography (OCT) is an intracoronary imaging technique that has superior spatial resolution compared to all other imaging modalities. High-resolution imaging of the vascular wall enables precise measurement of vessel wall and luminal dimensions, more accurately informing about the anatomic severity of epicardial stenoses, and also provides input for computational models to assess functional severity. The very high-resolution images also permit plaque characterization that may be informative for prognostication. Moreover, periprocedural imaging provides valuable information to guide lesion preparation, stent implantation and to evaluate acute stent complications for which iterative treatment might reduce the occurrence of major adverse stent events. As such, OCT represent a potential future all-in-one tool that provides the data necessary to establish the indications, procedural planning and optimization, and final evaluation of percutaneous coronary revascularization.

Treatment strategies of acute myocardial infarction: updates on revascularization, pharmacological therapy, and beyond

Owing to recent advances in early reperfusion strategies, pharmacological therapy, standardized care, and the identification of vulnerable patient subsets, the prognosis of acute myocardial infarction has improved. However, there is still considerable room for improvement. This review article summarizes the latest evidence concerning clinical diagnosis and treatment of acute myocardial infarction.

Implications of computed tomography reconstruction algorithms on coronary atheroma quantification: Comparison with intravascular ultrasound

BACKGROUND

Advances in coronary computed tomography angiography (CCTA) reconstruction algorithms are expected to enhance the accuracy of CCTA plaque quantification. We aim to evaluate different CCTA reconstruction approaches in assessing vessel characteristics in coronary atheroma using intravascular ultrasound (IVUS) as the reference standard.

METHODS

Matched cross-sections (n ​= ​7241) from 50 vessels in 15 participants with chronic coronary syndrome who prospectively underwent CCTA and 3-vessel near-infrared spectroscopy-IVUS were included. Twelve CCTA datasets per patient were reconstructed using two different kernels, two slice thicknesses (0.75 ​mm and 0.50 ​mm) and three different strengths of advanced model-based iterative reconstruction (IR) algorithms. Lumen and vessel wall borders were manually annotated in every IVUS and CCTA cross-section which were co-registered using dedicated software. Image quality was sub-optimal in the reconstructions with a sharper kernel, so these were excluded. Intraclass correlation coefficient (ICC) and repeatability coefficient (RC) were used to compare the estimations of the 6 CT reconstruction approaches with those derived by IVUS.

RESULTS

Segment-level analysis showed good agreement between CCTA and IVUS for assessing atheroma volume with approach 0.50/5 (slice thickness 0.50 ​mm and highest strength 5 ADMIRE IR) being the best (total atheroma volume ICC: 0.91, RC: 0.67, p ​< ​0.001 and percentage atheroma volume ICC: 0.64, RC: 14.06, p ​< ​0.001). At lesion-level, there was no difference between the CCTA reconstructions for detecting plaques (accuracy range: 0.64-0.67; p ​= ​0.23); however, approach 0.50/5 was superior in assessing IVUS-derived lesion characteristics associated with plaque vulnerability (minimum lumen area ICC: 0.64, RC: 1.31, p ​< ​0.001 and plaque burden ICC: 0.45, RC: 32.0, p ​< ​0.001).

CONCLUSION

CCTA reconstruction with thinner slice thickness, smooth kernel and highest strength advanced IR enabled more accurate quantification of the lumen and plaque at a segment-, and lesion-level analysis in coronary atheroma when validated against intravascular ultrasound.

CLINICALTRIALS

gov (NCT03556644).

Wall shear stress-related plaque growth of lipid-rich plaques in human coronary arteries: an near-infrared spectroscopy and optical coherence tomography study

AIMS

Low wall shear stress (WSS) is acknowledged to play a role in plaque development through its influence on local endothelial function. Also, lipid-rich plaques (LRPs) are associated with endothelial dysfunction. However, little is known about the interplay between WSS and the presence of lipids with respect to plaque progression. Therefore, we aimed to study the differences in WSS-related plaque progression between LRPs, non-LRPs, or plaque-free regions in human coronary arteries.

METHODS AND RESULTS

In the present single-centre, prospective study, 40 patients who presented with an acute coronary syndrome successfully underwent near-infrared spectroscopy intravascular ultrasound (NIRS-IVUS) and optical coherence tomography (OCT) of at least one non-culprit vessel at baseline and completed a 1-year follow-up. WSS was computed applying computational fluid dynamics to a three-dimensional reconstruction of the coronary artery based on the fusion of the IVUS-segmented lumen with a CT-derived centreline, using invasive flow measurements as boundary conditions. For data analysis, each artery was divided into 1.5 mm/45° sectors. Plaque growth based on IVUS-derived percentage atheroma volume change was compared between LRPs, non-LRPs, and plaque-free wall segments, as assessed by both OCT and NIRS. Both NIRS- and OCT-detected lipid-rich sectors showed a significantly higher plaque progression than non-LRPs or plaque-free regions. Exposure to low WSS was associated with a higher plaque progression than exposure to mid or high WSS, even in the regions classified as a plaque-free wall. Furthermore, low WSS and the presence of lipids had a synergistic effect on plaque growth, resulting in the highest plaque progression in lipid-rich regions exposed to low shear stress.

CONCLUSION

This study demonstrates that NIRS- and OCT-detected lipid-rich regions exposed to low WSS are subject to enhanced plaque growth over a 1-year follow-up. The presence of lipids and low WSS proves to have a synergistic effect on plaque growth.

Sex-specific features of optical coherence tomography detected plaque vulnerability related to clinical outcomes: insights from the CLIMA study

PURPOSE

To investigate the different impact of optical coherence tomography (OCT)-derived vulnerable plaque features on future adverse events (AEs) according to the biological sex.

METHODS

The prospective multicenter CLIMA study (ClinicalTrials.gov: NCT02883088) enrolled 1003 patients with OCT plaque analysis of non-treated coronary plaques located in the proximal left anterior descending artery. Sex-specific differences in plaque composition and vulnerable features were described. We investigated the incidence of AEs, including cardiac death, any myocardial infarction and target vessel revascularization at 1-year.

RESULTS

Among 1003 patients, 24.6% were women. Women were older and more frequently affected by chronic kidney disease. Dyslipidemia, prior MI and smoking habit were more common in men. At OCT analysis, women had shorter plaque length (p < 0.001), ticker fibrous cap (p = 0.001), smaller maximum lipid arc (p = 0.019), lower macrophage infiltration (p < 0.001) and intra-plaque layered tissue (p = 0.007). During follow-up, 65 AEs were registered. The presence of a thin fibrous cap and a large macrophage infiltration (> 67°) predicted AEs in both sexes. The presence of macrophages (HR 3.38, p = 0.018) and a small minimum lumen area (HR 4.97, p = 0.002) were associated with AEs in women but not in men, while a large lipid arc (> 180°) was associated with AEs in men (HR 2.56, p = 0.003) but not in women.

CONCLUSION

This subanalysis of the CLIMA study investigated for the first-time sex-specific OCT features of plaque vulnerability associated with AEs. Local inflammation was associated with AEs in women and a large lipid arc was predictive in men. OCT may help develop sex-specific risk stratification strategies.

Underlying Causes of Myocardial Infarction with Nonobstructive Coronary Arteries: Optical Coherence Tomography and Cardiac Magnetic Resonance Imaging Pilot Study

BACKGROUND

Scientific statements recommend multimodality imaging in myocardial infarction with non-obstructive coronary arteries (MINOCA) to define the underlying cause.

AIM

We evaluated the diagnostic yield of intravascular optical coherence tomography (OCT) and cardiac magnetic resonance (CMR) in the MINOCA setting.

METHODS

In this prospective, single center, observational pilot study, we enrolled patients with MINOCA without previous coronary interventions. All patients underwent three vessel OCT, followed by CMR. Imaging results were combined to determine the mechanism of MINOCA, when possible.

RESULTS

We enrolled 10 patients in this pilot study. Women constituted 50% of the analyzed population. The mean age of patients was 52 years. ST-segment elevation was found in 30% of patients. A possible culprit lesion was identified by OCT in 70% of participants, most commonly plaque rupture or erosion. An ischemic pattern of CMR abnormalities was identified in 70% of participants. Myocarditis and Tako-Tsubo were identified in 30%. A cause of MINOCA was identified in all patients using multimodality imaging, while using OCT alone identification occurred in only 70% of patients.

CONCLUSION

In this pilot study, multimodality imaging with OCT and CMR identified potential mechanisms in all patients with a diagnosis of MINOCA, and it has the potential to guide medical therapy for secondary prevention.

Narrowing disparities in PCI outcomes in women; From risk assessment, to referral pathways and outcomes

This review evaluates published data regarding outcomes for women with ACS undergoing PCI. Data is discussed from a patient centred perspective and timeline, beginning with sex-based differences in perception of risk, time to presentation, time to treatment, access to angiography, access to angioplasty, the impact of incomplete revascularization, prescribing practices, under-representation of women in randomized controlled trials and in cardiology physician workforces. The objective of the review is to identify factors contributing to outcome disparities for women with ACS, and to discuss potential solutions to close this outcome gap.

Intracoronary Imaging of Vulnerable Plaque-From Clinical Research to Everyday Practice

The introduction into clinical practice of intravascular imaging, including intravascular ultrasound (IVUS), optical coherence tomography (OCT) and their derivatives, allowed for the in vivo assessment of coronary atherosclerosis in humans, including insights into plaque evolution and progression process. Intravascular ultrasound, the most commonly used intravascular modality in many countries, due to its low resolution cannot assess many features of vulnerable plaque such as lipid plaque or thin-cap fibroatheroma. Thus, novel methods were introduced to facilitate this problem including virtual histology intravascular ultrasound and later on near-infrared spectroscopy and OCT. Howbeit, none of the currently used modalities can assess all known characteristics of plaque vulnerability; hence, the idea of combining different intravascular imaging methods has emerged including NIRS-IVUS or OCT-IVUS imaging. All of those described methods may allow us to identify the most vulnerable plaques, which are prone to cause acute coronary syndrome, and thus they may allow us to introduce proper treatment before plaque destabilization.

Safety and Efficacy of Drug-Coated Balloons in Patients with Acute Coronary Syndromes and Vulnerable Plaque

BACKGROUND

Percutaneous coronary intervention (PCI) is the main treatment option for acute coronary syndromes (ACS) often related to the progression and rupture of vulnerable plaques. While drug-eluting stents (DES) are now routinely used in PCI, drug-coated balloons (DCB) are a new strategy to PCI and their practice in the treatment of ACS with vulnerable plaques has not been reported. This study aimed to evaluate the safety and efficacy of DCB in ACS complicated with vulnerable plaque lesions.

METHODS

123 patients were retrospectively analyzed and diagnosed with ACS and given PCI in our Cardiology Department from December 2020 to July 2022. Vulnerable plaques were confirmed by intravenous ultrasound (IVUS) in all patients. According to individual treatment plan, patients were entered into either DCB (n = 55) or DES (n = 68) groups. The results of coronary angiography and IVUS before and immediately after percutaneous coronary intervention were analyzed. The occurrence of major adverse cardiovascular events (MACE) and the results of coronary angiography were also evaluated during follow-up.

RESULTS

There were no significant differences in baseline clinical characteristics, preoperative minimal luminal diameter (MLD), and preoperative diameter stenosis (DS) between the two groups. Also, there were no differences in IVUS plaque burden (PB), vessel area, and lumen area in the two groups before and immediately after PCI. The efficacy analysis showed that immediately after PCI, the DCB group had smaller MLD and higher degrees of lumen stenosis than the DES group (P < 0.05). However, during follow-up, no significant differences in MLD and DS were seen in two groups; relatively, late loss in luminal diameter（LLL）in the DCB group was smaller (P＜0.05). Safety analysis showed that during follow-up, 9 patients developed restenosis after DCB implantation while restenosis occurred in 10 patients with DES treatment, no statistical difference in the incidence of restenosis in the two groups. Besides, there was no statistical difference in the incidence of major adverse cardiac events（MACE）during hospitalization and follow-up in the DCB group (7.3% (4/55)) and the DES group (8.8% (6/68)).

CONCLUSION

DCB is safe and effective for ACS complicated with vulnerable plaque and has an advantage over DES in LLL.

Intravascular optical coherence elastography

Optical coherence elastography (OCE), a functional extension of optical coherence tomography (OCT), visualizes tissue strain to deduce the tissue's biomechanical properties. In this study, we demonstrate intravascular OCE using a 1.1 mm motorized catheter and a 1.6 MHz Fourier domain mode-locked OCT system. We induced an intraluminal pressure change by varying the infusion rate from the proximal end of the catheter. We analysed the pixel-matched phase change between two different frames to yield the radial strain. Imaging experiments were carried out in a phantom and in human coronary arteries in vitro. At an imaging speed of 3019 frames/s, we were able to capture the dynamic strain. Stiff inclusions in the phantom and calcification in atherosclerotic plaques are associated with low strain values and can be distinguished from the surrounding soft material, which exhibits elevated strain. For the first time, circumferential intravascular OCE images are provided side by side with conventional OCT images, simultaneously mapping both the tissue structure and stiffness.

Instantaneous Wave-Free Ratio for the Assessment of Intermediate Left Main Coronary Artery Stenosis: Correlations With Fractional Flow Reserve/Intravascular Ultrasound and Prognostic Implications: The iLITRO-EPIC07 Study

BACKGROUND

There is little information available on agreement between fractional flow reserve (FFR) and instantaneous wave-free ratio (iFR) in left main coronary artery (LMCA) intermediate stenosis. Besides, several meta-analyses support the use of FFR to guide LMCA revascularization, but limited information is available on iFR in this setting. Our aims were to establish the concordance between FFR and iFR in intermediate LMCA lesions, to evaluate with intravascular ultrasound (IVUS) in cases of FFR/iFR discordance, and to prospectively validate the safety of deferring revascularization based on a hybrid decision-making strategy combining iFR and IVUS.

METHODS

Prospective, observational, multicenter registry with 300 consecutive patients with intermediate LMCA stenosis who underwent FFR and iFR and, in case of discordance, IVUS and minimal lumen area measurements. Primary clinical end point was a composite of cardiovascular death, LMCA lesion-related nonfatal myocardial infarction, or unplanned LMCA revascularization.

RESULTS

FFR and iFR had an agreement of 80% (both positive in 67 and both negative in 167 patients); in case of disagreement (31 FFR+/iFR- and 29 FFR-/iFR+) minimal lumen area was ≥6 mm² in 8.7% of patients with FFR+ and 14.6% with iFR+. Among the 300 patients, 105 (35%) underwent revascularization and 181 (60%) were deferred according to iFR and IVUS. At a median follow-up of 20 months, major adverse cardiac events incidence was 8.3% in the defer group and 13.3% in the revascularization group (hazard ratio, 0.71 [95% CI 0.30-1.72]; P=0.45).

CONCLUSIONS

In patients with intermediate LMCA stenosis, a physiology-guided treatment decision is feasible either with FFR or iFR with moderate concordance between both indices. In case of disagreement, the use of IVUS may be useful to indicate revascularization. Deferral of revascularization based on iFR appears to be safe in terms of major adverse cardiac events.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT03767621.

Morphometric Assessment for Functional Evaluation of Coronary Stenosis with Optical Coherence Tomography and the Optical Flow Ratio in a Vessel with Single Stenosis

Objectives: The study aimed to evaluate the diagnostic performance of optical coherence tomography (OCT) in identifying functionally significant coronary stenosis in a vessel with single stenosis. Background: The OCT-based morphofunctional computational method for deriving the optical flow ratio (OFR) has diagnostic value, as it can identify the functional severity of coronary stenosis, but the ability of the OFR to aid the OCT in determining coronary stenosis hemodynamics in single-stenosis lesion remains unclear. Methods: 74 vessels with single stenosis were studied in 69 patients; all cases were performed through OCT and quantitative flow ratio (QFR), and OCT images were used to perform OFR. Results: Among vessels with single stenosis, OFR showed a good correlation with QFR (r = 0.86; p < 0.001). Taking QFR as the standard, the vessel-level diagnosis accuracy, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of OFR were 90% (95% CI: 81 to 96), 94% (95% CI: 77 to 99), 88% (95% CI: 74 to 96), 85% (95% CI: 68 to 94) and 95% (95% CI: 82 to 99), respectively. Among vessels with OFR/QFR concordance, both the minimum lumen area (MLA) and minimum lumen diameter (MLD) showed excellent diagnostic efficiency (MLA: area under the curve (AUC) = 0.92, 95% CI: 0.85 to 0.98, p < 0.001; MLD: AUC = 0.93, 95% CI: 0.86 to 0.98, p < 0.001) in determining the functional significance of coronary stenosis in a single stenosis lesion, and the best cutoff values were 1.55 mm2 and 1.40 mm. Conclusions: OFR has a good correlation with QFR. OCT-measured MLA and MLD have excellent diagnostic efficiency in identifying the hemodynamic significance of coronary stenosis in a vessel with single stenosis.

Percutaneous Coronary Angioplasty in Patients with Cancer: Clinical Challenges and Management Strategies

The number of cancer survivors in the United States is projected to increase by 31% by 2030. With advances in early screening, diagnosis and therapeutic strategies, a steadily increasing number of patients are surviving cancer. Coronary artery disease (CAD) is now one of the leading causes of death amongst cancer survivors, with the latter group of patients having a higher risk of CAD compared to the general population. Our review covers a range of specific challenges faced by doctors when considering percutaneous coronary interventions (PCI) in cancer patients; clinical outcomes in cancer patients undergoing PCI, as well as some important technical considerations to be made when making decisions regarding the management strategy in this special population of patients.

Gut Microbiota and Coronary Plaque Characteristics

Background The relationship between gut microbiota and in vivo coronary plaque characteristics has not been reported. This study was conducted to investigate the relationship between gut microbiota and coronary plaque characteristics in patients with coronary artery disease. Methods and Results Patients who underwent both optical coherence tomography and intravascular ultrasound imaging and provided stool and blood specimens were included. The composition of gut microbiota was evaluated using 16S rRNA sequencing. A total of 55 patients were included. At the genus level, 2 bacteria were associated with the presence of thin-cap fibroatheroma, and 9 bacteria were associated with smaller fibrous cap thickness. Among them, some bacteria had significant associations with inflammatory/prothrombotic biomarkers. Dysgonomonas had a positive correlation with interleukin-6, Paraprevotella had a positive correlation with fibrinogen and negative correlation with high-density lipoprotein cholesterol, Succinatimonas had positive correlations with fibrinogen and homocysteine, and Bacillus had positive correlations with fibrinogen and high-sensitivity C-reactive protein. In addition, Paraprevotella, Succinatimonas, and Bacillus were also associated with greater plaque volume. Ten bacteria were associated with larger fibrous cap thickness. Some were associated with protective biomarker changes; Anaerostipes had negative correlations with trimethylamine N-oxide, tumor necrosis factor α, and interleukin-6, and Dielma had negative correlations with trimethylamine N-oxide, white blood cells, plasminogen activator inhibitor-1, and homocysteine, and a positive correlation with high-density lipoprotein cholesterol. Conclusions Bacteria that were associated with vulnerable coronary plaque phenotype and greater plaque burden were identified. These bacteria were also associated with elevated inflammatory or prothrombotic biomarkers. Registration URL: https://www.umin.ac.jp/ctr/; Unique identifier: UMIN000041692.

Application of optical coherence tomography in decision-making of post-thrombectomy adjunctive treatments

An adult patient with acute basilar artery occlusion underwent mechanical thrombectomy. After complete reperfusion, a 70% residual stenosis of the proximal basilar artery was observed. Intravascular optical coherence tomography (OCT) identified lipid plaques with an intact fibrous cap and thrombus in the culprit lesion, indicating plaque erosion was the mechanism of in situ thrombosis. Adjunctive antiplatelet therapy rather than rescue interventions was pursued for its beneficial effects in acute coronary syndrome caused by plaque erosion. The patient had a 90-day modified Rankin Scale score of 0. OCT enables precise evaluation of vessel characteristics following thrombectomy, so may improve outcomes through subsequent tailored treatments.