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

ANOCA, INOCA, MINOCA: The New Frontier of Coronary Syndromes

The growing prevalence in the diagnosis of INOCA (Ischemia with Non-Obstructive Coronary Arteries), ANOCA (Angina with Non-Obstructive Coronary Arteries), and MINOCA (Myocardial Infarction with Non-Obstructive Coronary Arteries) highlights the need to reassess their clinical relevance. Historically regarded as benign syndromes, emerging evidence suggests that these conditions may cause serious cardiovascular events and considerable long-term disability. Additionally, emerging studies suggest that non-obstructive coronary artery disease (CAD) may have a higher prevalence compared to traditional obstructive forms of CAD. This leads to the need to better clarify the underlying pathogenic mechanisms as well as the risk factors associated with these syndromes. This is precisely the aim of this review, which focuses on the complex and heterogeneous mechanisms underlying these syndromes as well as the associated risk factors. This review also sums up the diagnostic steps necessary to achieve an accurate diagnosis, along with the interventional and pharmacological approaches to be implemented in light of the latest evidence.

Comparing FFR-Guided Complete Revascularization and Conservative Management for Non-Culprit Lesions in STEMI Patients With Multivessel Disease: A Systematic Review and Meta-Analysis

BACKGROUND

In patients with ST-segment elevation myocardial infarction (STEMI) and multivessel coronary artery disease, the optimal management strategy for non-culprit lesions is a subject of ongoing debate. There has been an increasing use of physiology-guidance to assess the extent of occlusion in non-culprit lesions, and hence the need for stenting. Fractional flow reserve (FFR) is commonly used as a technique. This analysis compares FFR versus conservative management in the management of non-culprit lesions in STEMI patients with multivessel disease.

METHODS

A comprehensive literature search was conducted on databases from inception to May 25, 2024. We conducted a random-effects meta-analysis using RevMan version 5.3.0, employing the Der-Simonian and Laird method to combine the data.

RESULTS

The analysis of five RCTs including 3759 patients revealed a significantly lower incidence of major adverse cardiovascular events (composite of all-cause mortality, non-fatal myocardial infarction and the need for repeat revascularization [PCI or CABG]) in the FFR group compared to the conservative management group (RR = 0.65, 95% CI: 0.44-0.96, p = 0.03). The revascularization rates were significantly lower in the FFR group (RR = 0.53, 95% CI: 0.43-0.66, p < 0.00001). Additionally, unplanned hospitalization leading to urgent repeat revascularization and any cause hospitalization were significantly lower in the FFR group (RR = 0.72, 95% CI: 0.56-0.94, p = 0.01), and (RR = 0.62, 95% CI: 0.46-0.84, p = 0.002), respectively. The FFR group had a higher risk of definite stent thrombosis (RR = 2.26, 95% CI: 1.10-4.64, p = 0.03). No significant differences were observed between the two groups in mortality, hospitalization for heart failure, or myocardial infarction. Similarly, bleeding rates, cerebrovascular accidents (CVAs), and contrast-induced nephropathy (CIN) were comparable between both groups.

CONCLUSION

Our findings support FFR-guided PCI to manage non-culprit lesions in STEMI patients with multivessel disease as it is potentially safe, with comparable rates of bleeding, CVAs and CIN. It also improves clinical outcomes, as well as reduces revascularization and hospitalization rates. The risk of stent thrombosis remains a concern, and hence the decision making for FFR-guided complete revascularization should take into account the complexity/risk of the procedure, as well as the patients' individual co-morbidities and preferences.

Non-culprit plaque healing on serial OCT imaging and future outcome in patients with acute coronary syndromes

BACKGROUND AND AIMS

Histologic studies indicated that healed plaque, characterized by a multilayered pattern, is indicative of prior atherothrombosis and subsequent healing. However, longitudinal in vivo data on healed plaque formation in non-culprit plaques are limited. This study aimed to investigate serial changes and clinical significance of new layered pattern formation in non-culprit plaques in patients with acute coronary syndromes (ACS) using serial optical coherence tomography (OCT) imaging.

METHODS

ACS patients who underwent two OCTs at baseline and 1-year follow-up were included. Serial changes in morphologic characteristics of non-culprit plaques were evaluated. New layered pattern was defined as a new signal-rich layer on the plaque surface at follow-up that was not present at baseline.

RESULTS

Among 553 non-culprit plaques observed in 222 patients, 82 (14.8 %) exhibited a new layered pattern at follow-up. Thin-cap fibroatheroma, macrophage, and thrombus were identified as independent predictors of the new layered pattern. Plaques with new layered pattern formation showed a greater significant reduction in luminal area and lipid content, as well as a greater increase in fibrous cap thickness compared to those without. The incidence of 6-year non-culprit-related major adverse cardiac events was higher in patients with new layered pattern than in those without (25.4 % vs. 10.8 %, p = 0.011), mainly due to clinically driven coronary revascularization.

CONCLUSIONS

Plaque destabilization and subsequent healing frequently occur in non-culprit plaques after ACS. The formation of a new layered pattern may contribute to temporary plaque stabilization, but results in luminal stenosis and worse clinical outcomes.

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.

CVIT 2025 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.

Effect of Intravascular Ultrasonography (IVUS) Imaging on Stent Optimization in Patients Achieving Optimal Results After Angiographic-Guided Stent Implantation: A Non-randomized Interventional Study

BACKGROUND

Angiography possesses limitations in assessing plaque composition, vessel width, diffuse reference vessel disease, lesion severity, and the success or failure of stent placement. Intravascular ultrasonography (IVUS) helps address several of these issues by offering enhanced visualization of the coronary architecture and stent placement.

METHODS

This study was conducted at the Department of Cardiology of All India Institute of Medical Sciences, Rishikesh. It spanned 12 months with a six-month follow-up and involved post-angiography-guided angioplasty and stenting. All patients underwent IVUS pullback. Due to the non-working of the unspecified surgical package under the Ayushman Bharat scheme, the study included 16 patients, with an intended target of 30 patients.

RESULTS

Half of the patients (eight, 50%) presented with acute coronary syndrome, while the other half presented with chronic stable angina. Left main coronary artery disease was present in 50% of patients, and 13 (81.25%) had complex coronary artery lesions. After angiography-guided angioplasty, IVUS pullback on all patients revealed that only three patients (18.75%) required post-IVUS optimization of the stent.

CONCLUSION

The majority of patients did not require post-IVUS optimization following angiography-guided angioplasty and stenting. No major adverse cardiovascular events were recorded, and no target vessel myocardial infarction (MI), target vessel revascularization, target lesion revascularization, or stent thrombosis (ST) were reported over the six-month follow-up period.

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.

Panvascular concept in the evaluation and treatment of intracranial atherosclerotic stenosis

Cerebrovascular disease is the leading causes of death and disability worldwide. Intracranial atherosclerotic stenosis (ICAS) is one of the major causes of ischemic stroke, especially in the Asian population. It is urgent to explore effective screening methods for early diagnosis to improve prognosis of patients with ICAS. Recently, the concept of panvascular medicine has provided a direction for the exploration of evaluation of ICAS. Based on the concept of "panvascular medicine," atherosclerosis is the common pathological feature of panvascular disease, such as ICAS and coronary artery disease (CAD). In-depth research on the formation and development of plaques, the development and application of more precise preoperative assessment and detection methods, and the utilization of new interventional equipment have greatly enhanced the precision of diagnosis and treatment of CAD. Studies attempt to apply similar evaluation and treatment in ICAS. The deeper understanding, the more accurate diagnosis and treatment, contributing to improve the prognosis of patients with ICAS. This review focuses on these evaluations and treatment of CAD applied in the field of ICAS.

Superiority of photon-counting computed tomography for detecting high-risk unstable angina patients: two case reports

Coronary artery disease is the leading cause of death among non-communicable diseases. The management strategy prioritizes early detection and optimal treatment, with emerging roles for imaging approaches. Photon-counting computed tomography is a new non-invasive diagnostic imaging tool that can detect high-risk plaques in coronary artery disease patients. Using photon-counting computed tomography in screening and intravascular ultrasound later in verifying diagnosis and intervention guidance could be a new technique to swiftly discover unstable plaques, prepare lesions for surgery, and determine the optimal percutaneous intervention strategy. However, there is no documentation available for this new approach. We reported two acute coronary syndromes managed with a combination of two imaging methods. Despite receiving medical therapy, the first case continued to experience chest pain, leading to the detection of plaque ulceration in the left anterior descending artery. On the other hand, two PCCT screenings within 6 months revealed plaque progression in the second case. We then used IVUS to confirm the lesions and proceed to intervention. We successfully discharged both cases, and they showed no symptoms 6 months after discharge.

Long-term Follow-up Optical Coherence Tomography Assessment of Primary Percutaneous Coronary Intervention for Unprotected Left Main

Background

Elective unprotected left main (ULM) percutaneous coronary intervention (PCI) has long-term mortality rates comparable to surgical revascularization, thanks to advances in drug-eluting stent (DES) design, improved PCI techniques, and frequent use of intravascular imaging. However, urgent PCI of ULM culprit lesions remains associated with high in-hospital mortality and unfavourable long-term outcomes, including DES restenosis and stent thrombosis (ST). This analysis aimed to examine the long-term outcomes and healing of DES implanted in ULM during primary PCI using high-resolution optical coherence tomography (OCT) imaging.

Methods

A total of 15 consecutive patients undergoing long-term OCT follow-up of ULM primary PCI from a high-volume center were included in this analysis. During the index primary PCI all subjects underwent angio-guided DES implantation, and follow-up was uneventful in all but one subject who had a non-target PCI lesion. The primary endpoint was the percentage of covered, uncovered, and malappossed stent struts at long-term follow-up. Secondary endpoints included quantitative and qualitative OCT measurements. For the left main bifurcation, a separate analysis was performed for three different segments: left main (LM), polygon of confluence (POC) and distal main branch (dMB), in all cases.

Results

The average follow-up interval until OCT was 1580 ± 1260 days. Despite aorto-ostial stent protrusions in 40% of patients, optimal image quality was achieved in 93.3% of cases. There were higher rates of malapposed (11.4 ± 16.6 vs. 13.1 ± 8.3 vs. 0.3 ± 0.5%; p < 0.001) and lower rates of covered struts (81.7 ± 16.8 vs. 83.7 ± 9.2 vs. 92.4 ± 6.8%; p = 0.041) observed for the LM and POC segment compared to the dMB. Significantly malapposed stent struts (>400 μm) were less likely to be covered at follow-up, than struts with a measured strut to vessel wall distance of <400 μm (15.4 ± 21.6 vs. 24.8 ± 23.9%; p = 0.011). Neoatherosclerosis was observed in 5 (33.3%) and restenotic neointimal hyperplasia (NIH) in 2 (13.3%) patients, requiring PCI in 33.3% of patients.

Conclusions

Long-term OCT examination of DES implanted during primary PCI for culprit ULM lesions demonstrated high rates of incomplete strut coverage, late malapposition, and high subclinical DES failure rates. These negative OCT results highlight the need for image optimization strategies during primary PCI to improve DES-related long-term outcomes.

Unlocking the Secrets of Acute Coronary Syndromes Using Intravascular Imaging: From Pathophysiology to Improving Outcomes

Acute coronary syndrome (ACS) represents the most severe manifestation of coronary artery disease. Intravascular imaging, both intravascular ultrasound (IVUS) and optical coherence tomography (OCT), have played crucial roles for the impressive reduction in mortality of ACS. Intravascular imaging is useful for the detection of atherosclerotic mechanism (plaque rupture, calcified nodules, or plaque erosions) and for the evaluation of nonatherosclerotic and nonobstructive types of ACS. In addition, IVUS and OCT play a crucial role in the optimization of the PCI. The aim of the current review is to present the role of intravascular imaging in identifying the mechanisms of ACS and its prognostic role in future events, to review the current guidelines suggesting intravascular imaging use in ACS, to summarize its role in PCI in patients with ACS, and to compare IVUS and OCT.

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. In this White Paper we summarize 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 nonobstructive coronary disease. The findings presented followed the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system in an expert consensus process that involved a diverse writing group vetted by a review group. Expert consensus was achieved around 9 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, and in 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 who present with myocardial infarction with nonobstructive coronary disease 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 presented in this White Paper will help to guide the use of intravascular imaging toward situations in which the balance of efficacy, safety, and cost are most optimal.

Lipid-lowering Therapy and Coronary Plaque Regression

Lipid-lowering therapy plays a central role in reducing cardiovascular events. Over the past few decades, clinical trials utilizing several imaging techniques have consistently shown that lipid-lowering therapy can reduce the coronary plaque burden and improve plaque composition. Although intravascular ultrasound has been the most extensively used modality to assess plaque burden, other invasive modalities, such as optical coherence tomography and near-infrared spectroscopy, provide relevant data on plaque vulnerability, and computed tomography angiography detects both plaque volume and characteristics non-invasively. A large body of evidence supports the notion that reducing low-density lipoprotein cholesterol using statins combined with ezetimibe and proprotein convertase subtillisin/kexin type 9 inhibitors consistently shows improvements in plaque burden and favorable morphological changes. This review summarizes previously obtained data on the impact of lipid-lowering treatment strategies on atherosclerotic plaque regression, as assessed using several imaging modalities.

MINOCA: A Pathophysiological Approach of Diagnosis and Treatment-A Narrative Review

Myocardial infarction with non-obstructive coronary arteries (MINOCA) is a clinical entity characterized by the absence of significant coronary artery obstruction in epicardial arteries (<50%) on coronary angiography in the setting of acute myocardial infarction (AMI). This article aims to provide a narrative review of the pathophysiological mechanisms, diagnostic challenges, and prognosis associated with MINOCA based on pathophysiology regarding the atherosclerotic and non-atherosclerotic causes. Etiological factors, including thromboembolism, coronary artery spasm, spontaneous coronary artery dissection, coronary microvascular disease, and supply-demand mismatch, are addressed. Imaging modalities such as echocardiography, advances in coronary angiography like intravascular ultrasound (IVUS) and optical coherence tomography (OCT), cardiac magnetic resonance (CMR), and coronary computed tomography angiography (CCTA) are also analyzed. MINOCA patients have a better short-term prognosis compared to those with obstructive coronary artery disease but face significant long-term risks, underscoring the need for precise diagnosis and management strategies. Elevated inflammatory markers and specific genetic predispositions are also associated with adverse outcomes in MINOCA. This review focused on MINOCA from a pathophysiological perspective on the diverse underlying mechanisms, the challenges in achieving accurate diagnosis, the importance of a tailored therapeutic approach and the necessity for further investigation of clinical outcomes.

Functional and morphological improvement of significant non-culprit coronary artery stenosis by LDL-C reduction with a PCSK9 antibody: Rationale and design of the randomized FITTER trial

Non-culprit coronary artery lesions are commonly present in patients presenting with an acute coronary syndrome (ACS). Additional stenting of non-culprit lesions in addition to the culprit lesion intends to prevent secondary events caused by these lesions. At the same time, multiple trials have demonstrated the potential of proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors in reducing plaque size and changing plaque composition of non-culprit lesions. Whether intensive low-density lipoprotein cholesterol (LDL-C) reduction with PCSK9 inhibitor evolocumab improves non-culprit vessel hemodynamics, reduces the risk of plaque rupture of important non-culprit lesions, and might obviate the need for additional stenting has not been investigated. The "Functional Improvement of non-infarcT related coronary artery stenosis by Extensive LDL-C Reduction with a PCSK9 Antibody" (FITTER) trial is a multi-center, randomized, double-blind, placebo-controlled clinical trial for patients presenting with ACS and multivessel disease (MVD). After treatment of the culprit lesion, fractional flow reserve (FFR) is performed in non-culprit vessels amenable for percutaneous coronary intervention (PCI). Coronary intervention in patients with hemodynamically important non-critical lesions (FFR: 0.67-0.85) is staged after baseline imaging using near-infrared spectroscopy (NIRS) and intravascular ultrasound (IVUS). Eligible patients are randomized and treated for 12 weeks with either evolocumab or placebo, in addition to high-intensity statin therapy. Follow-up angiography with repeat FFR and IVUS-NIRS is scheduled at 12 weeks. Staged PCI is performed at the operator's discretion.The FITTER trial is the first study to evaluate the effect of maximal LDL-C reduction by the PCSK9 inhibitor evolocumab on invasively measured FFR, plaque size, and plaque composition in hemodynamically important non-culprit lesions, during a treatment period of just 12 weeks after an ACS. Currently, all patients have been included (August 2023) and data analysis is ongoing.

Trial registration number

clinicaltrials.gov NCT04141579.

Optical Coherence Tomography in Myocardial Infarction Management: Enhancing Precision in Percutaneous Coronary Intervention

In acute myocardial infarction (AMI), the urgency of coronary revascularization through percutaneous coronary intervention (PCI) is paramount, offering notable advantages over pharmacologic treatment. However, the persistent risk of adverse events, including recurrent AMI and heart failure post-revascularization, underscores the necessity for enhanced strategies in managing coronary artery disease. Traditional angiography, while widely employed, presents significant limitations by providing only two-dimensional representations of complex three-dimensional vascular structures, hampering the accurate assessment of plaque characteristics and stenosis severity. Intravascular imaging, specifically optical coherence tomography (OCT), significantly addresses these limitations with superior spatial resolution compared to intravascular ultrasound (IVUS). Within the context of AMI, OCT serves dual purposes: as a diagnostic tool to accurately identify culprit lesions in ambiguous cases and as a guide for optimizing PCI procedures. Its capacity to differentiate between various mechanisms of acute coronary syndrome, such as plaque rupture and spontaneous coronary dissection, enhances its diagnostic potential. Furthermore, OCT facilitates precise lesion preparation, optimal stent sizing, and confirms stent deployment efficacy. Recent meta-analyses indicate that OCT-guided PCI markedly improves safety and efficacy in revascularization, subsequently decreasing the risks of mortality and complications. This review emphasizes the critical role of OCT in refining patient-specific therapeutic approaches, aligning with the principles of precision medicine to enhance clinical outcomes for individuals experiencing AMI.

Precision Medicine in Acute Coronary Syndromes

Nowadays, current guidelines on acute coronary syndrome (ACS) provide recommendations mainly based on the clinical presentation. However, greater attention is being directed to the specific pathophysiology underlying ACS, considering that plaque destabilization and rupture leading to luminal thrombotic obstruction is not the only pathway involved, albeit the most recognized. In this review, we discuss how intracoronary imaging and biomarkers allow the identification of specific ACS endotypes, leading to the recognition of different prognostic implications, tailored management strategies, and new potential therapeutic targets. Furthermore, different strategies can be applied on a personalized basis regarding antithrombotic therapy, non-culprit lesion revascularization, and microvascular obstruction (MVO). With respect to myocardial infarction with non-obstructive coronary arteries (MINOCA), we will present a precision medicine approach, suggested by current guidelines as the mainstay of the diagnostic process and with relevant therapeutic implications. Moreover, we aim at illustrating the clinical implications of targeted strategies for ACS secondary prevention, which may lower residual risk in selected patients.

Five-year follow-up of OCT-guided percutaneous coronary intervention in patients with ST-segment elevation myocardial infarction

BACKGROUND

Compared with intravascular ultrasound guidance, there is limited evidence for optical coherence tomography (OCT) guidance during primary percutaneous coronary intervention (pPCI) in ST-segment elevation myocardial infarction (STEMI) patients.

AIMS

We investigated the role of OCT in guiding a reperfusion strategy and improving the long-term prognosis of STEMI patients.

METHODS

All patients who were diagnosed with STEMI and who underwent pPCI between January 2017 and December 2020 were enrolled and divided into OCT-guided versus angiography-guided cohorts. They had routine follow-up for up to 5 years or until the time of the last known contact. All-cause death and cardiovascular death were designated as the primary and secondary endpoints, respectively.

RESULTS

A total of 3,897 patients were enrolled: 2,696 (69.2%) with OCT guidance and 1,201 (30.8%) with angiographic guidance. Patients in the OCT-guided cohort were less often treated with stenting during pPCI (62.6% vs 80.2%; p<0.001). The 5-year cumulative rates of all-cause mortality and cardiovascular mortality in the OCT-guided cohort were 10.4% and 8.0%, respectively, significantly lower than in the angiography-guided cohort (19.0% and 14.1%; both log-rank p<0.001). All 4 multivariate models showed that OCT guidance could significantly reduce 5-year all-cause mortality (hazard ratio [HR] in model 4: 0.689, 95% confidence interval [CI]: 0.551-0.862) and cardiovascular mortality (HR in model 4: 0.692, 95% CI: 0.536-0.895). After propensity score matching, the benefits of OCT guidance were consistent in terms of all-cause mortality (HR: 0.707, 95% CI: 0.548-0.913) and cardiovascular mortality (HR: 0.709, 95% CI: 0.526-0.955).

CONCLUSIONS

Compared with angiography alone, OCT guidance may change reperfusion strategies and lead to better long-term survival in STEMI patients undergoing pPCI. Findings in the current observational study should be further corroborated in randomised trials.

Image-guided percutaneous revascularization of the coronary arteries

The European Society of Cardiology recently updated guidelines on the management of chronic coronary syndromes upgrading the use of intracoronary imaging for complex percutaneous coronary interventions (PCI) to a class 1A recommendation. It is essential that the interventional community appreciate the additive value of intracoronary imaging over angiography alone-not only to obtain optimal acute PCI results but also to improve longer-term cardiovascular outcomes. The purpose of this manuscript is to review the latest evidence that informed the recent guideline recommendations and expand on the specific role of the different imaging modalities before, during, and after PCI.

Long-term outcomes of IVUS-guided and angiography-guided drug-eluting stent implantation for left main coronary artery disease: a retrospective consort study

BACKGROUND

In patients with unprotected left main coronary artery disease (ULMCAD), this study compared the long-term prognosis of drug-eluting stent insertion guided by intravascular ultrasonography (IVUS) vs. angiography.

PATIENTS AND METHODS

This retrospective consort investigation was performed in December 2021. This analysis included 199 patients who underwent IVUS-guided (IVUS group, n = 81) or angiography-guided (angiography group, n = 118) drug-eluting stent implantation at the Affiliated Hospital of Inner Mongolia Medical University between September 2013 and September 2018. Major adverse cardiac events (MACE) were defined as cardiovascular death, sudden cardiac death, myocardial infarction.

RESULTS

The IVUS group had considerably lower proportions of MACE within 1 year postoperatively (P = 0.002) and cardiac mortality within 3 years postoperatively (P = 0.018) compared to the angiography group. However, after adjusting for confounding variables, the hazard ratio for 3-year cardiac mortality was similar between the two groups (P = 0.28). In the IVUS group, there was considerably greater minimum lumen diameter (MLD) (P = 0.046), and reduced frequencies of target vessel restenosis (P < 0.050) and myocardial infarction (MI) (P = 0.024) compared to the angiography group. Cox regression analysis for 3-year cardiac mortality found that MSD was independently associated with low cardiac mortality (HR = 0.1, 95% CI: 0.01-14.92, P = 0.030).

CONCLUSION

IVUS-guided drug-eluting stent implantation may lead to better long-term prognosis in patients with ULMCAD, and MSD may be a predictor for lower cardiac mortality.

Stratified medicine for acute and chronic coronary syndromes: A patient-tailored approach

The traditional approach to management of cardiovascular disease relies on grouping clinical presentations with common signs and symptoms into pre-specified disease pathways, all uniformly treated according to evidence-based guidelines ("one-size-fits-all"). The goal of precision medicine is to provide the right treatment to the right patients at the right time, combining data from time honoured sources (e.g., history, physical examination, imaging, laboratory) and those provided by multi-omics technologies. In patients with ischemic heart disease, biomarkers and intravascular assessment can be used to identify endotypes with different pathophysiology who may benefit from distinct treatments. This review discusses strategies for the application of stratified management to patients with acute and chronic coronary syndromes.

Association of in situ thrombus within the patent foramen ovale and patients with migraine: A prospective cohort study

Background

Patent foramen ovale (PFO) is associated with migraine; however, the mechanism of PFO-associated migraine is not well known; additionally, percutaneous closure is controversial. This study aimed to investigate in situ thrombi within the PFO and explore the possible predictors of the effectiveness of PFO closure in migraineurs.

Methods

This prospective cohort study included 48 asymptomatic patients and 92 migraineurs with PFO. Optical coherence tomography (OCT) was used to evaluate the PFO microstructure. Only migraineurs underwent percutaneous closure. Migraineurs were divided into two cohorts based on the presence of a thrombus within the PFO. The symptoms were assessed at the 12-month follow-up visit. Predictors were evaluated employing multivariate logistic regression and receiver operating characteristic curve analyses.

Results

In situ thrombi within PFO were identified in 69 migraineurs and in two asymptomatic patients (76.7 % vs. 4.3 %; P < 0.001). Additionally, endocardial irregularity, discontinuity, low signal, and spasm were found in 59 (65.6 %), 15 (16.7 %), 13 (14.4 %), and six (6.7 %) patients, respectively, in the migraine group. In situ thrombus was associated with migraine risk (OR 49.03; 95%CI 8.52-282.18; P < 0.001). At the 12-month follow-up of the migraineur cohort, the primary endpoint, a 50 % reduction in migraine frequency after closure (with or without thrombus in PFO) was met (85.3 % vs. 25.0 %; P < 0.001). In situ thrombus was associated with migraine relief (OR 6.75; 95%CI 1.28-35.56; P = 0.024).

Conclusions

In situ thrombus and abnormal endocardium within PFOs were common in migraineurs, and in situ thrombus was a risk factor for migraine. Percutaneous closure was more effective in migraineurs with thrombi within the PFO. OCT imaging improved the understanding of pathogenic PFOs and may be helpful in selecting suitable migraineurs for PFO closure.

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.

Atherosclerotic Plaque Erosion: Mechanisms, Clinical Implications, and Potential Therapeutic Strategies-A Review

ABSTRACT

Atherosclerosis is an insidious and progressive inflammatory disease characterized by the formation of lipid-laden plaques within the intima of arterial walls with potentially devastating consequences. While rupture of vulnerable plaques has been extensively studied, a distinct mechanism known as plaque erosion (PE) has gained recognition and attention in recent years. PE, characterized by the loss of endothelial cell lining in the presence of intact fibrous cap, contributes to a significant and growing proportion of acute coronary events. However, despite a heterogeneous substrate underlying coronary thrombosis, treatment remains identical. This article provides an overview of atherosclerotic PE characteristics and its underlying mechanisms, highlights its clinical implications, and discusses potential therapeutic strategies.

Role of Lipid-Lowering and Anti-Inflammatory Therapies on Plaque Stabilization

Atherosclerosis is the predominant underlying etiopathology of coronary artery disease. Changes in plaque phenotype from stable to high risk may spur future major adverse cardiac events (MACE). Different pharmacological therapies have been implemented to mitigate this risk. Over the last two decades, intravascular imaging modalities have emerged in clinical studies to clarify how these therapies may affect the composition and burden of coronary plaques. Lipid-lowering agents, such as statins, ezetimibe, and proprotein convertase subtilisin/kexin type 9 inhibitors, were shown not only to reduce low-density lipoprotein levels and MACE but also to directly affect features of coronary plaque vulnerability. Studies have demonstrated that lipid-lowering therapy reduces the percentage of atheroma volume and number of macrophages and increases fibrous cap thickness. Future studies should answer the question of whether pharmacological plaque stabilization may be sufficient to mitigate the risk of MACE for selected groups of patients with atherosclerotic coronary disease.

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.

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.

No-reflow after primary percutaneous coronary intervention in patients with ST-elevation myocardial infarction: an angiographic core laboratory analysis of the TOTAL Trial

BACKGROUND

The optimal strategy to prevent no-reflow in ST-elevation myocardial infarction (STEMI) patients undergoing percutaneous coronary intervention (PCI) is unknown.

AIMS

We aimed to examine the effect of thrombectomy on the outcome of no-reflow in key subgroups and the adverse clinical outcomes associated with no-reflow.

METHODS

We performed a post hoc analysis of the TOTAL Trial, a randomised trial of 10,732 patients comparing thrombectomy versus PCI alone. This analysis utilised the angiographic data of 1,800 randomly selected patients.

RESULTS

No-reflow was diagnosed in 196 of 1,800 eligible patients (10.9%). No-reflow occurred in 95/891 (10.7%) patients randomised to thrombectomy compared with 101/909 (11.1%) in the PCI-alone arm (odds ratio [OR] 0.95, 95% confidence interval [CI]: 0.71-1.28; p-value=0.76). In the subgroup of patients who underwent direct stenting, those randomised to thrombectomy compared with PCI alone experienced less no-reflow (19/371 [5.1%] vs 21/216 [9.7%], OR 0.50, 95% CI: 0.26-0.96). In patients who did not undergo direct stenting, there was no difference between the groups (64/504 [12.7%] vs 75/686 [10.9%)], OR 1.18, 95% CI: 0.82-1.69; interaction p-value=0.02). No-reflow patients had a significantly increased risk of experiencing the primary composite outcome (cardiovascular death, recurrent myocardial infarction, cardiogenic shock, or NYHA Class IV heart failure) at 1 year (adjusted hazard ratio 1.70, 95% CI: 1.13-2.56; p-value=0.01).

CONCLUSIONS

In patients with STEMI treated by PCI, thrombectomy did not reduce no-reflow in all patients but may be synergistic with direct stenting. No-reflow is associated with increased adverse clinical outcomes.