Intracoronary Imaging Modalities Research Articles

Intracoronary imaging guidance of percutaneous coronary interventions: how and when to apply validated metrics to improve the outcome.

Percutaneous coronary intervention (PCI) is still burdened by a substantial number of complications despite constant technological advances, including the advent of intracoronary imaging (ICI) techniques. ICI modalities have been instrumental for the understanding the mechanism of PCI failure. Thanks to the ability to detail the pre-intervention coronary anatomy and identify the features indicative of sub-optimal stent deployment, ICI techniques can be utilised to improve coronary interventions in different clinical scenarios. More recently large randomized clinical trials on ICI guidance confirmed the clinical effectiveness of this approach especially in complex high-risk interventions.

Intracoronary imaging to guide percutaneous coronary intervention: from evidence to guidelines.

Despite notable advances in devices and techniques, percutaneous coronary intervention (PCI) is still affected by a substantial number of complications and failure rates. Over the years, the use of intracoronary imaging (ICI) has dramatically improved the understanding of mechanical and technical factors related to successful and failed PCI, becoming a mainstay in complex trans-catheter interventions. However, ICI modalities are invasive, time-consuming, and costly, and a net clinical benefit needs to be shown in order to recommend their routine use in clinical practice. In the past, the lack of evidence from randomized trials has been reflected in the scepticism shown by international guidelines. The recent publication of large randomized clinical trials conducted worldwide has provided new evidence regarding the clinical usefulness of ICI guidance in PCI. The consistent reduction of adverse events achieved in these trials, also demonstrated in an updated meta-analysis, suggested that the use of ICI in PCI is compelling to achieve optimal technical results and better outcomes, especially in complex high-risk interventions. Also considering the burden of information provided by ICI on coronary artery disease, looking from the inside seems today an opportunity that modern cardiology cannot ignore anymore.

Drug intervention as an emerging concept for secondary prevention in patients with coronary disease.

Non-culprit lesion-related coronary events are a significant concern in patients with coronary artery disease (CAD) undergoing coronary intervention. Since several studies using intra-coronary imaging modalities have reported a high prevalence of vulnerable plaques in non-culprit lesions at the initial coronary event, the immediate stabilization of these plaques by intensive pharmacological regimens may contribute to the reduction in the adverse events. Although current treatment guidelines recommend the titration of statin and other drugs to attain the treatment goal of low-density lipoprotein cholesterol (LDL-C) level in patients with CAD, the early prescription of strong LDL-C lowering drugs with more intensive regimen may further reduce the incidence of recurrent cardiovascular events. In fact, several studies with intensive regimen have demonstrated a higher percentage of patients with the attainment of LDL-C treatment goal in the early phase following discharge. In addition to many imaging studies showing plaque stabilization by LDL-C lowering drugs, several recent reports have shown the efficacy of early statin and proprotein convertase subtilisin/kexin type 9 inhibitors on the immediate stabilization of non-culprit coronary plaques. To raise awareness regarding this important concept of immediate plaque stabilization and subsequent reduction in the incidence of recurrent coronary events, the term 'Drug Intervention' has been introduced and gradually applied in the clinical field, although a clear definition is lacking. The main target of this concept is patients with acute coronary syndrome as a higher prevalence of vulnerable plaques in non-culprit lesions in addition to the worse clinical outcomes has been reported in recent imaging studies. In this article, we discuss the backgrounds and the concept of drug intervention.

Current role of intravascular imaging in percutaneous treatment of calcified coronary lesions.

Percutaneous treatment of calcified coronary lesions is still a challenge in modern interventional cardiology practice. Coronary angiography is limited to the precise and quantitative assessment of calcium in coronary arteries. Intracoronary imaging (ICI) modalities, including optical coherence tomography (OCT) and intravascular ultrasound (IVUS), produce a very detailed image of calcifications and could help in proper percutaneous treatment. Intracoronary imaging indicates the need to use additional tools and improves the final effect of an intervention. Drawing on the already published literature, the authors focused on the qualification of patients to the procedure, conduct and result of interventional procedures involving calcified lesions supported by ICI. The article shows the advantages and disadvantages of both ICI methods in general and especially in calcified lesions. Currently available tools dedicated to dealing with coronary calcium and helping to meet optimal stent implantation criteria are also described. This article reviews the data on ICI implementation in daily clinical practice to improve the results of percutaneous interventions, and indicates further directions.

Role of intracoronary imaging in severely calcific disease

<p>Coronary artery calcium (CAC) poses a major challenge during percutaneous coronary intervention (PCI). The prevalence of significant calcium is reported to be as high as 32%, with higher incidences in the male sex, alongside hypertension, an ST-segment elevation myocardial infarction (STEMI) presentation, and an advancing age. The identification and modification of calcium is important as an association between the presence of CAC and the observation of major adverse cardiovascular events, even in asymptomatic patients. Although angiographically-identified calcium likely reflects the highest burden disease, an inability to assess the calcium, both qualitatively and quantitatively, limits the interventionists in their strategy to achieve an optimal PCI result. Additionally, treating a stent underexpansion in a heavily calcified vessel is more difficult than preventing it. Intra-coronary imaging modalities such as optical coherence tomography (OCT) and intra-vascular ultrasound (IVUS) offer upfront valuable information that may guide the choice of calcium modification tools, evaluate the efficacy of modification/debulking, and permit an optimal stent expansion. Contemporary randomised studies of intra-coronary imaging- vs angiography-guided intervention have demonstrated a clear benefit in adopting an image-guided approach. This review article summarises the value of IVUS and OCT in patients who present with severe calcific diseases.</p>

Intracoronary imaging of complex coronary artery lesions: A lesion-level analysis from SCAAR simulating the IMPROVE trial

Abstract Background Intravascular ultrasound (IVUS) and optical coherence tomography (OCT) are two intracoronary imaging modalities which can be used to optimize stent implantation and expansion. The IMPROVE trial is an ongoing randomized study investigating the impact of IVUS on percutaneous coronary intervention (PCI) of complex lesions. We conducted a nationwide retrospective observational study simulating the IMPROVE trial. Purpose The aim of this study is to determine whether intracoronary imaging is associated with improved outcome after PCI of complex lesions. Methods Using the Swedish Coronary Angiography and Angioplasty registry (SCAAR) we identified complex lesions undergoing PCI between 1 January 2016 and 15 January 2022. Complex lesions were defined as (1) in-stent restenosis, (2) chronic total occlusions, (3) bifurcations and (4) lesions stented with a ≥ 28 mm stent. Lesions were stratified into two groups according to use of intracoronary imaging or not. The groups underwent propensity score (PS) matching to balance baseline demographics. Outcome was assessed with univariable cox regression models and Kaplan Meier estimates. The primary endpoint was target lesion revascularization (TLR) within 2-years assessed on lesion level where each patient could contribute with more than one lesion. Secondary endpoint included all-cause mortality analyzed on patient level. Results After PS-matching, two groups with 9,404 lesions each were formed. Baseline characteristics after PS matching did not show any significant demographic differences. The intracoronary imaging group contributed more often with more than one lesion. Intracoronary imaging was associated with significantly lower rates of TLR (hazard ratio (HR): 0.80 (95% confidence interval (CI): 0.67-0.94), p=0.008) and all-cause mortality (HR: 0.69 (95% CI 0.61-0.78), p<0.001). Conclusion In this study on complex lesions undergoing PCI, the use of intracoronary imaging was associated with an improved outcome. These results encourage intracoronary imaging when assessing complex lesions.Baseline characteristicsOutcome

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.

Effects of Lipid Lowering Therapies on Vulnerable Plaque Features: An Updated Narrative Review of the Literature.

The clinical evidence on the efficacy of lipid lowering therapy in patients with coronary artery disease (CAD) is unequivocally established. However, the effects of these therapies on plaque composition and stability are less clear. The use of intracoronary imaging (ICI) technologies has emerged as a complement to conventional angiography to further characterize plaque morphology and detect high-risk plaque features related to cardiovascular events. Along with clinical outcomes studies, parallel imaging trials employing serial evaluations with intravascular ultrasound (IVUS) have shown that pharmacological treatment has the capacity to either slow disease progression or promote plaque regression, depending on the degree of lipid lowering achieved. Subsequently, the introduction of high-intensity lipid lowering therapy led to much lower levels of low-density lipoprotein cholesterol (LDL-C) levels than achieved in the past, resulting in greater clinical benefit. However, the degree of atheroma regression showed in concomitant imaging trials appeared more modest as compared to the magnitude of clinical benefit accrued from high-intensity statin therapy. Recently, new randomized trials have investigated the additional effects of achieving very low levels of LDL-C on high-risk plaque features-such as fibrous cap thickness and large lipid accumulation-beyond its size. This paper provides an overview of the currently available evidence of the effects of moderate to high-intensity lipid lowering therapy on high-risk plaque features as assessed by different ICI modalities, reviews data supporting the use of these trials, and analyse the future perspectives in this field.

Coronary thrombus after cannabis consumption: the important role of intracoronary imaging modalities

Coronary thrombus after cannabis consumption: the important role of intracoronary imaging modalities

The PACMAN-AMI trial: a revolution in the treatment of acute coronary syndromes.

After an acute coronary syndrome (ACS), the risk of major adverse cardiovascular events (MACE) persists despite the reperfusion of the culprit lesion. The addition of proprotein convertase subtilisin/kexin type 9 inhibitors (PCSK9i) to standard lipid-lowering therapies has been demonstrated to effectively reduce the levels of low-density lipoprotein cholesterol (LDL-C), with a consistent decrease of MACE in large, randomized clinical trials enrolling patients at high risk of cardiovascular events. There is a strong rationale for an immediate and aggressive LDL-C lowering with the use of PCSK9i in ACS patients. The PACMAN-AMI trial tested this hypothesis demonstrating that in ACS patients, the addition of subcutaneous biweekly alirocumab, compared with placebo, to high-intensity statin therapy resulted in significantly greater coronary plaque regression in non-infarct-related arteries after 52 weeks, as assessed by novel intra-coronary imaging modalities. These findings might provide the mechanistic rationale in favour of early initiation of very intensive LDL-C-lowering therapy in the acute setting of ACS, potentially modifying the actual common pattern of treatment.

Role of plaque imaging for identification of vulnerable patients beyond the stage of myocardial ischemia.

Chronic coronary syndrome (CCS) is a progressive disease, which often first manifests as acute coronary syndrome (ACS). Imaging modalities are clinically useful in making decisions about the management of patients with CCS. Accumulating evidence has demonstrated that myocardial ischemia is a surrogate marker for CCS management; however, its ability to predict cardiovascular death or nonfatal myocardial infarction is limited. Herein, we present a review that highlights the latest knowledge available on coronary syndromes and discuss the role and limitations of imaging modalities in the diagnosis and management of patients with coronary artery disease. This review covers the essential aspects of the role of imaging in assessing myocardial ischemia and coronary plaque burden and composition. Furthermore, recent clinical trials on lipid-lowering and anti-inflammatory therapies have been discussed. Additionally, it provides a comprehensive overview of intracoronary and noninvasive cardiovascular imaging modalities and an understanding of ACS and CCS, with a focus on histopathology and pathophysiology.

Role of Intracoronary Imaging in Myocardial Infarction with Non-Obstructive Coronary Disease (MINOCA): A Review.

Myocardial infarction with non-obstructive coronary artery disease occurs in 6% to 15% of all presentation of myocardial infarctions. The pathophysiologic mechanisms of MINOCA include epicardial vasospasm, coronary microvascular disorder, spontaneous coronary artery dissection, and coronary thrombus/embolism. The diagnosis is challenging, supported by intracoronary imaging with intravascular ultrasound (IVUS) and optical coherent tomography (OCT), coronary physiology testing, and cardiac magnetic resonance imaging (CMR). OCT is able to identify atherosclerotic causes of MINOCA (plaque erosion, plaque rupture, and calcified nodule) and nonatherosclerotic causes (spontaneous artery dissection, and spasm). In this review, we summarize the performance of the two intracoronary imaging modalities (IVUS and OCT) in MINOCA and discuss the importance of supplementing these modalities with CMR in order to drive target therapy.

A State-Of-The-Art Review on Coronary Artery Border Segmentation Algorithms for Intravascular Ultrasound (IVUS) Images.

Intravascular Ultrasound images (IVUS) is a useful guide for medical practitioners to identify the vascular status of coronary arteries in human beings. IVUS is a unique intracoronary imaging modality that is used as an adjunct to angioplasty to view vessel structures using a catheter with high resolutions. Segmentation of IVUS images has always remained a challenging task due to various impediments, for example, similar tissue components, vessel structures, and artifacts imposed during the acquisition process. Many researchers have applied various techniques to develop standard methods of image interpretation, however, the ultimate goal is still elusive to most researchers. This challenge was presented at the MICCAI- Computing and Visualization for (Intra)Vascular Imaging (CVII) workshop in 2011. This paper presents a major review of recently reported work in the field, with a detailed analysis of various segmentation techniques applied in IVUS, and highlights the directions for future research. The findings recommend a reference database with a larger number of samples acquired at varied transducer frequencies with special consideration towards complex lesions, suitable validation metrics, and ground-truth definition as a standard against which to compare new and current algorithms.

Prediction of optical coherence tomography-detected calcified nodules using coronary computed tomography angiography

Diagnosis of calcified nodules (CNs) is critical in the proper management of coronary artery disease, but CNs can be detected only using intracoronary imaging modalities. This study aimed to investigate the ability of coronary computed tomography angiography (CCTA) in predicting CNs detected using optical coherence tomography (OCT). From 138 patients who underwent OCT-guided percutaneous coronary intervention (PCI) after CCTA evaluation, 141 PCI target vessels were retrospectively enrolled and classified into CN (12 vessels/11 patients; CNs in the PCI culprit lesion) and non-CN (129 vessels/127 patients; without CNs) groups based on the OCT analysis. Retrospective CCTA analysis revealed significantly higher coronary artery calcification score (CACS), calcified plaque volume (CPV), and maximum calcified plaque area (MCPA) of the target vessel in the CN group than in the non-CN group. Receiver operating characteristic curve indicated that CACS ≥ 162 (area under the ROC curve (AUC 0.76, sensitivity 83.3%, specificity 54.2%), CPV ≥ 20.1 mm3 (AUC 0.83, sensitivity 100%, specificity 57.3%), and MCPA ≥ 4.51 mm2 (AUC 0.87, sensitivity 91.7%, specificity 78.3%) were the best cutoff values for predicting CNs. MCPA showed the highest AUC among all the CCTA parameters. In conclusion, CCTA is useful for predicting OCT-detected CNs in PCI target vessels.

From regression to stabilization: new insights into the evolution of coronary atherosclerotic plaque

Coronary artery atherosclerosis is a constantly evolving disease. Over the years, new drug therapies have been shown to reduce adverse cardiovascular events and improve the survival of patients with coronary artery disease. New intracoronary imaging modalities, including intravascular ultrasound, optical coherence tomography, and near-infrared spectroscopy, have been introduced to detect the anatomic changes which follow an effective lipid-lowering therapy in human coronary plaques. Particularly, the use of optical coherence tomography made it possible to evaluate plaque composition and showed how an intensive lipid-lowering therapy can stabilize atherosclerosis by improving vulnerable plaque features. Future non-invasive applications are required for large-scale use of these findings.

Abstract 10907: Woven Coronary Artery: A River With Many Currents

Introduction: Congenital coronary artery anomalies can increase the risk of cardiovascular events and sudden death. A woven coronary artery is a rare abnormality with multiple lumens in a single vessel, giving the appearance of complex coronary plaque or a dissection flap on coronary angiography. Clinical Case: A 57-year-old man with group IV pulmonary hypertension and chronic right-sided heart failure presented for consideration of pulmonary endarterectomy. He underwent preoperative coronary angiography which demonstrated nonobstructive disease within the left anterior descending and circumflex arteries and a complex lesion in the right coronary artery (RCA- Figure 1). The lesion was further evaluated using intravascular ultrasound (IVUS) which demonstrated numerous, complex, communicating lumens and fenestrations within a single external elastic lamina suggestive of a woven coronary artery anomaly (Figure 2). This was recognized as a benign abnormality for which the patient was managed medically, and he underwent a successful pulmonary endarterectomy several days later. Discussion: Woven coronary arteries are rare and complex lesions made up of numerous lumens often found in the proximal to mid-RCA. These lesions typically permit normal blood flow and are found incidentally in asymptomatic patients. Woven coronary arteries can be mistaken for complex lesions, dissection, or recanalized thrombus, leading to unnecessary and potentially dangerous percutaneous coronary intervention. Woven arteries should not be treated with angioplasty in the absence of thrombotic occlusion as this can lead to arterial vessel damage. Intracoronary imaging, including IVUS, is vital to differentiate woven coronary arteries from other coronary pathologies. Conclusion: Woven coronary arteries may mimic dissection or recanalized thrombus, but can be promptly recognized as a benign congenital anomaly with intracoronary imaging modalities such as IVUS.

Intracoronary Imaging in left main stent percutaneous coronary intervention has a clear survival benefit particularly in more complex patients

Abstract Background Left Main Stem Disease (LMS) is prognostically important coronary artery disease that is managed either with coronary artery bypass surgery (CABG) or percutaneous coronary intervention (PCI). Use of intracoronary imaging (ICI) modalities such as intravascular ultrasound (IVUS) and optical coherence tomography (OCT) have been shown to improve outcomes with PCI revascularization. The primary objective of this study was to evaluate the impact of ICI on outcomes following LMS PCI. Methods Retrospective observation study of 498 (5.1% of all PCI cases) patients who had undergone LMS PCI at our tertiary primary PCI centre hospital over a 11-year period between July 2010-July 2021. Data was collected from electronic medical records. Follow-up was also obtained through linkage with the Office of National Statistics. Results The mean age at the time of enrolment was 70.7±11.5 years. Majority of the patients were male 351 (70.5%). 353 (70.9%) of cases had acute coronary syndrome (ACS) presentation while the remainder were elective procedures. Mean follow-up duration was 3.75±3.06 years. Survival calculated by Kaplan-Meier was 70%. 87 patients (17.5%) deceased during first year of enrolment. 344 (69.1%) patients had ICI, with IVUS in 316 (63.5%) and OCT in 28 (5.6%) patients. IVUS comprised 91.9% of ICI procedures. Protected LMS (OR 0.175, 95% CI: 0.037–0.833, P-value=0.029) and the use of left ventricular mechanical support device (OR 0.324, 95% CI: 0.122–0.859, P-value=0.024) were associated with decreased odds of undergoing an ICI. Patients undergoing ICI had significantly better survival compared to those without ICI (HR: 0.54, P<0.001). Moreover, OCT showed significantly better survival compared with IVUS (HR: 0.181, P=0.017). Use of ICI was associated with better survival in patients who had Rotablation (HR: 0.455, 95% CI: 0.232–0.892, P=0.022), ACS (HR: 0.523, 95% CI: 0.383–0.714, P<0.001) or comorbidities of diabetes and stroke (HR: 0.551, 95% CI: 0.337–0.807, P=0.002). Conclusion ICI in LMS PCI has a significant survival benefit in our dataset. This is especially the case in patients presenting with ACS, those with comorbidities of Diabetes mellitus and stroke and those undergoing rotablation. Funding Acknowledgement Type of funding sources: None.

Finding the Road to Rome in Cardiac Allograft Vasculopathy Imaging Surveillance.

Finding the Road to Rome in Cardiac Allograft Vasculopathy Imaging Surveillance.

Effects of aggressive predilatation, sizing, and postdilatation strategy for coronary bioresorbable vascular scaffolds implantation.

The results of the recent Amsterdam Investigator-Initiated Absorb Strategy All-Comers trial showed that the predilatation, sizing, and postdilatation (PSP) technique did not lower the long-term rates of scaffold thrombosis and adverse events. We evaluated the impact of aggressive PSP bioresorbable vascular scaffold (BRS) implantation on the short- and long-term clinical outcomes. From June 2014 to December 2016, 150 patients with BRS implantation were enrolled and received successful percutaneous coronary intervention (PCI), of whom 104 received aggressive PSP technique (high-pressure predilatation and lesion preparation in addition to the traditional PSP technique). Short- and long-term outcomes were compared. All patients underwent successful PCI and BRS implantation with final Thrombolysis in Myocardial Infarction grade 3 flow. The baseline and procedure characteristics were similar in both groups. Debulking techniques were used in 13 (8.7%) patients. Intracoronary imaging modalities were used in 73 (48.7%) patients. After BRS implantation, no adverse events were observed within 30 days in both groups. During the mean follow-up period of 2.98 ± 0.77 years, 12 (8.0%) patients experienced major adverse cardiovascular events (MACEs), including one cardiovascular death (0.6%), three nonfatal myocardial infarction (2.0 %), and 11 target-vessel revascularization (7.3 %). Multivariate Cox regression analysis showed that aggressive PSP remained an independent protective factor for MACEs. Moreover, the use of intracoronary imaging and rotablation atherectomy was associated with better clinical outcomes. Lesion preparation by aggressive PSP in BRS implantation was associated with better long-term clinical outcomes.

Clinical use of intracoronary imaging modalities in Poland. Expert opinion of the Association of Cardiovascular Interventions of the Polish Cardiac Society.

The article presents the most common, current indications for the use of intravascular invasive imag-ing diagnostic techniques, i.e. intravascular ultrasound and optical coherence tomography in Polish invasive cardiology centers. The application of the above-mentioned techniques in the diagnosis of stenosis of the left main coronary artery, optimization of stent implantation procedures, treatment of calcified lesions, and other clinically important issues are discussed.