Acute Coronary Syndrome Lesions Research Articles

Quantitative flow ratio or angiography for the assessment of non-culprit lesions in acute coronary syndromes, a randomized trial.

Patients undergoing percutaneous coronary intervention for acute coronary syndromes often have multivessel disease (MVD). Quantitative flow ratio (QFR) is an angiography-based technology that may help quantify the functional significance of non-culprit lesions, with the advantage that measurements are possible also once the patient is discharged from the catheterization laboratory. Our two-center, randomized superiority trial aimed to test whether QFR, as compared to angiography, modifies the rate of non-culprit lesion interventions (primary functional endpoint) and improves the outcomes of patients with acute coronary syndromes and MVD (primary clinical endpoint). In total, 202 consecutive patients (64 [56-71] years of age, 160 men) with STEMI (n = 69 (34%)), NSTEMI (n = 94 (47%)), or unstable angina (n = 39 (19%)) and MVD who had undergone successful treatment of all culprit lesions were randomized 1:1 to angiography- vs. QFR-guided delayed revascularization of 246 non-culprit stenoses (1.2/patient). The proportion of patients assigned to medical treatment versus percutaneous intervention was not different between groups (angiography group: 45 (45%) vs. QFR: 56 (55%), P = 0.125; relative risk = 0.80 (0.60-1.06)). At 12months, a primary clinical endpoint event (composite of death, nonfatal myocardial infarction, revascularization, and significant angina) occurred in 24 patients (angiography-guided) and 23 patients (QFR-guided; P = 0.637, HR = 1.16 [0.63-2.15]). None of its components was different between groups. QFR guidance based on analysis of images from the primary intervention was not associated with a difference in the rate of non-culprit lesion staged revascularization nor in the 12-month incidence of clinical events in patients with acute coronary syndromes and multivessel disease. ClinicalTrials.gov Registry (NCT04808310).

Poor prognosis of patients with acute coronary syndrome presenting optical coherence tomography-defined calcified nodule at culprit lesions after emergent percutaneous coronary intervention

Abstract Background Optical coherence tomography (OCT) enables the diagnosis of underlying causes of acute coronary syndrome (ACS). Calcified nodule (CN) is reported to be a rare but important cause of ACS, although its prognostic impact on clinical outcomes after emergent percutaneous coronary intervention (EPCI) remains undetermined. TACTICS registry is an investigator-initiated, prospective, multicenter, observational study to be conducted at 22 hospitals in Japan to clarify the prevalence of underlying causes of ACS defined by OCT (plaque rupture [PR], plaque erosion [PE] and CN) and its impact on clinical outcomes, and assess the feasibility of OCT-guided emergent PCI (UMIN-CTR, ID 000039050). Purpose This study aimed to clarify the prevalence of CN at the culprit lesions in ACS patients and its prognostication after EPCI in a large prospective registry. Methods We assessed 702 patients enrolled in TACTICS registry who underwent OCT assessment of the culprit lesion during EPCI. Advanced chronic kidney disease (CKD) was defined as those with creatinine clearance <30 ml/min/1.73m2. The prevalence of OCT-defined CN and occurrence of MACE, defined as a composite of cardiovascular death, myocardial infarction, heart failure, or ischemia-driven unplanned revascularization at 1 year were compared between patients with and without advanced CKD. Result Patients with advanced CKD was found in 5.4% of a total cohort. The prevalence of CN was 3.0% in patients with non-advanced CKD and 21.1% in those with advanced CKD (p<0.001). In advanced CKD, MACE occurred most frequently in patients with CN (87.5%), followed by plaque rupture (11.8%) and plaque erosion (10.0%) (p<0.001). In Cox hazard analysis, CN was a significant predictor for MACE in advanced CKD (hazard ratio [HR], 12.94 (3.31-50.67), p<0.001). In contrast, CN was not significant predictor for MACE in non-advanced CKD (HR1.931 (0.706-5.281), p=0.200). Conclusion CN is significantly more frequently found at the culprit lesions of ACS in advanced CKD patients. CN was associated with poor outcome in advanced CKD patients.

Monocyte-to-High Density Lipoprotein Cholesterol Ratio Positively Predicts Coronary Artery Disease and Multi-Vessel Lesions in Acute Coronary Syndrome.

We investigated the hypothesis that MHR (monocyte-to-high density lipoprotein cholesterol ratio) is related to the severity of coronary artery in ACS (acute coronary syndrome). In this case-control study, we recruited 15,853 participants undergoing the first time percutaneous coronary intervention (PCI) including 4093 normal controls, 10,518 chronic coronary artery disease (CAD), and 1242 ACS cases. Examination of demographic clinical data and biochemical profiles, as well as MHR values, were performed before PCI. The relationship between MHR and severity of coronary artery lesion in ACS was analyzed. We also used a flow cytometric assay to distinguish CD14+/CD16- classical monocyte subsets in peripheral blood mononucleated cells from CAD patients. MHR was higher in patients with ACS compared with MHR in normal control and chronic CAD (normal control vs chronic CAD vs ACS: 0.46 ± 0.27 × 109/mmol vs 0.53 ± 0.29 × 109/mmol vs 0.73 ± 0.47 × 109/mmol, P < 0.001). MHR showed a significantly progressive increase as the angiographic severity of coronary lesions increased (single vessel lesion vs multi-vessel lesions in ACS: 0.54 ± 0.31 × 109/mmol vs 0.58 ± 0.35 × 109/mmol, P < 0.001), and classical monocyte subset to HDL-C ratio (CMHR) was increased in with CAD patients compared with control [4.69 (IQR, 1.06, 2.97) × 103/mmol vs 1.92 (IQR, 0.92, 3.04) × 103/mmol, P = 0.02]. Using a multivariate analysis, after adjusting for age, gender, body mass index (BMI), diabetes, and dyslipidemia, MHR was positively associated with multi-vessel lesions in ACS [OR (odds ratio): 1.28 (95% CI: 1.03-1.59, P = 0.029)]. MHR level could be a potential predictor of coronary artery lesion severity in ACS.

The Value of the Apolipoprotein B/Apolipoprotein A1 Ratio in Predicting the Rapid Progression of Non-Culprit Coronary Lesions in Acute Coronary Syndrome in Patients with Diabetes Mellitus after Percutaneous Coronary Intervention.

This study aims to assess the predictive value of the apolipoprotein B (ApoB) /apolipoprotein A1 (ApoA1) ratio in acute coronary syndrome (ACS) in patients with diabetes mellitus (DM) for the rapid progression (RP) of non-culprit coronary lesions (NCCLs) after percutaneous coronary intervention (PCI) and observe the effect of the ApoB/ApoA1 ratio on major adverse cardiac events (MACE).A total of 175 patients with DM presenting with ACS who received a PCI and an average 13-month follow-up coronary angiography (CAG) were enrolled from January 2015 to December 2020. According to the CAG, the patients were divided into the RP group and the non-RP group. MACE was defined as a composite of death from cardiac causes, cardiac arrest, myocardial infarction, or rehospitalization from unstable or progressive angina at the end of a 24-month follow-up.The low-density lipoprotein cholesterol (LDL-C), ApoB, ApoB/ApoA1 ratio, and LDL-C/high-density lipoprotein cholesterol (HDL-C) ratio levels at baseline were significantly higher in the RP group than in the non-RP group. The ApoA1 level at baseline in the non-RP group was significantly higher than in the RP group. The predictive significance of the ApoB/ApoA1 ratio (area under the curve (AUC) = 0.712) for the RP of NCCLs was significantly higher than those of ApoA1, ApoB, LDL-C/HDL-C ratio (AUC = 0.628, AUC = 0.640, and AUC = 0.620, respectively). A higher ApoB/ApoA1 ratio and the RP of NCCLs were significantly associated with the occurrence of MACE.The ApoB/ApoA1 ratio was an effective clinical indicator for the RP of NCCLs after PCI in patients with DM presenting with ACS. The high ApoB/ApoA1 ratio and the RP of NCCLs were two risks for MACE.

Model development and validation of noninvasive parameters based on coronary computed tomography angiography to predict culprit lesions in acute coronary syndromes within 3 years: value of plaque characteristics, hemodynamics and pericoronary adipose tissue.

Machine learning (ML) is combined with noninvasive parameters from coronary computed tomography angiography (CTA) to construct predictive models to identify culprit lesions that may lead to acute coronary syndrome (ACS). We retrospectively analyzed 132 patients with ACS at the Fourth Affiliated Hospital of Harbin Medical University who had coronary CTA between 3 months and 3 years before the ACS event, with a total of 240 lesions. Lesions from 2020 (n=154) were included in the training set, and lesions from 2021 (n=86) were included in the test set for internal validation. We evaluated the role of plaque characteristics, hemodynamic parameters and pericoronary adipose tissue (PCAT) attenuation from CTA in identifying culprit ACS lesions. In the training set, logistic regression was used to screen CTA-derived parameters with P values <0.05 for the model construction. Logistic regression, random forest, Bayesian and K-nearest neighbor algorithms were used to build classification models, and their performance was assessed using the test set. The following models were established to evaluate the effectiveness of different combinations of models to identify culprit lesions: Model 1 was established for plaque characteristics; Model 2 was established for hemodynamic parameters; Model 3 was established for PCAT attenuation; Model 4 was established for plaque characteristics and hemodynamic parameters; and Model 5 was established for plaque characteristics, hemodynamic parameters and PCAT attenuation. A total of ten high-risk factors were screened for the ML model construction, and the ML model based on the logistic regression algorithm had the best performance among the four algorithms (accuracy =0.721; sensitivity =0.892; specificity =0.592; positive prediction =0.623; and negative prediction =0.879). In this model, the minimum lumen area, positive remodeling and lesion-specific fat attenuation index (FAI) were the risk factors significantly associated with the culprit lesion. Analysis of the effect of different combinations of models to identify culprit lesions showed that Model 5 had the best predictive effect (AUC =0.819 and 95% CI: 0.722-0.916). ACS can be predicted using ML based on CTA parameters. Compared to other models, the model combining plaque characteristics, hemodynamic parameters and PCAT attenuation performed best in predicting the culprit lesion.

Comparison of single-stent and double-stent strategies for stenting a complex bifurcation lesion of the left main coronary artery in hemodynamically stable patients with acute coronary syndrome. Randomized study protocol (non-inferiority)

To date, a single­stent strategy for stenting bifurcation lesions is considered the most optimal and is recommended for routine use. However, there are complex lesions that are unique in terms of morphological and anatomical features. Such lesions are not clearly defined in literature and may require an alternative approach to stenting. In this study, a complex bifurcation lesion of the left main coronary artery is presented, as well as a prospective randomized analysis of immediate and long­term outcomes of two approaches to stenting such lesions (single­stent and double­stent) in hemodynamically stable patients with acute coronary syndrome. Objective. To perform a comparative analysis of intraoperative, immediate and long­term outcomes of single­stent and double­stent strategies for stenting a complex bifurcation lesion of the left main coronary artery (LMCA) in hemodynamically stable patients with acute coronary syndrome (ACS). Materials and methods. To the open prospective randomized single­center (non­inferiority) study it is planned to enroll 114 hemodynamically stable patients with ACS (n=114) and complex (according to study criteria) bifurcation lesions of the LMCA; patients will undergo a single­stent or double­stent strategy of percutaneous coronary intervention (PCI) with implantation of drug­eluting stents. Randomization into two groups will be performed after coronary angiography, confirmation of eligibility (checking for inclusion criteria and exclusion criteria), and signing of informed consent; group 1 ­ single­stent stenting strategy; group 2 ­ double­stent stenting strategy. The total duration of the study will be 52 weeks, with mandatory telephone calls on 30th (±3 days) and 364th (±3 days) day after PCI and the final in­person visit after the entire follow­up period. Over the course of the study, patients will receive optimal drug therapy according to clinical recommendations. During the follow­up period, information will be collected on the clinical status of patients, events in the combined control points, compliance/adjustment of drug therapy. During in­person visit, patients will undergo multispiral computed tomography of coronary arteries. Combined primary endpoint: cardiac death, non­fatal myocardial infarction, acute cerebrovascular accident and repeated revascularization of target vessel. Combined secondary endpoint: thrombosis and restenosis of the stent. Conclusion. In our study, a bifurcation lesion of the LMCA, unique in terms of morphological and anatomical criteria, will be identified in hemodynamically stable patients with ACS. This is a complex lesion that may initially require double­stent approach to stenting, which differs from the recommended single­stent strategy. Keywords: percutaneous coronary intervention, bifurcation stenting, single­stent technique, double­stent technique, culotte­stenting, crush­stenting, TAP­stenting, complex lesion, acute coronary heart disease

Feasibility of rotational atherectomy in patients with acute coronary syndrome: favorable in-hospital outcomes and clinical importance of complexed coronary atherosclerosis.

The feasibility of rotational atherectomy (RA) during percutaneous coronary intervention (PCI) in patients who present with acute coronary syndrome (ACS) remains fully unsettled. We retrospectively evaluated 198 consecutive patients who underwent RA during PCI from 2009 to 2020. All patients underwent intracoronary imaging (intravascular ultrasound 96.5%, optical coherence tomography 9.1%, both 5.6%) during PCI. Patients who underwent RA during PCI were divided into two groups: ACS (n = 49; unstable angina pectoris, n = 27; non-ST-elevation myocardial infarction, n = 18, and ST-elevation myocardial infarction, n = 4) and chronic coronary syndrome (CCS) (n = 149). The RA procedural success rate was comparable between in the ACS and CCS groups (93.9 vs. 89.9%, P = 0.41). No significant differences were observed in procedural complications and in-hospital death between the groups. The incidence of major adverse cardiovascular event (MACE) after 2years was significantly higher in ACS group compared with CCS group (38.7 vs. 17.4%, log-rank P = 0.002). Multivariable Cox regression analysis identified SYNTAX score or CABG SYNTAX score > 22 (hazard ratio (HR) 2.66, 95% confidence interval (CI) 1.40-5.06, P = 0.002) and mechanical circulatory support during the procedure (HR 2.61, 95% CI 1.21-5.59, P = 0.013) as predictors of MACE at 2years, but not ACS on index admission (HR 1.58, 95% CI 0.84-2.99, P = 0.151). RA procedure is feasible as a bail-out strategy for ACS lesions. However, more complexed coronary atherosclerosis and mechanical circulatory support during RA procedure, but no ACS lesions were associated with worse mid-term clinical outcomes.

Identification of predictors for the comprehensive clinical risk and severity of coronary lesions of acute coronary syndrome.

Acute coronary syndrome (ACS) is the most common cause of death in patients with coronary artery disease. The aim of the study was to identify the predictors of both comprehensive clinical risk and severity of coronary lesions by comprehensive use of GRACE and SYNTAX scores in patients with ACS. Clinical data of 225 ACS patients who underwent coronary angiography between 2015 and 2016 were collected. Multiple logistic regression analysis (stepwise) was used to identify the predictors. The predictive ability of predictors and the model were determined using receiver operating characteristics analyses. Multivariable logistic regression analyses showed that high aspartate aminotransferase (AST) predicted the comprehensive clinical risk with odds ratios (ORs) and 95% confidence intervals (CIs) of 1.011 (1.002-1.021). High total cholesterol (TC) and red blood cell distribution width (RDW) predicted the severity of coronary lesions with ORs and 95% CIs of 1.517 (1.148-2.004) and 1.556 (1.195-2.028), respectively. Low prealbumin predicted both severity of coronary lesions and comprehensive clinical risk of ACS patients with ORs and 95% CIs of 0.743 (0.672-0.821) and 0.836 (0.769-0.909), respectively. The model with a combination of prealbumin and AST had the highest predictive efficacy for comprehensive clinical risk, and the combination of prealbumin, TC, and RDW had the highest predictive efficacy for the severity of coronary lesions. The sensitivity and specificity, and the optimal cut-off values of these four indexes were determined. Four predictors for the comprehensive clinical risk and severity of coronary lesions of ACS were identified, which provided important information for the early diagnosis and appropriate treatment of ACS.

Clinical Characteristics and Outcomes of Chinese Patients with Premature Acute Coronary Syndrome

This study aimed to investigate the clinical characteristics and major adverse cardiovascular events (MACEs) of Chinese patients with premature acute coronary syndrome (ACS) undergoing percutaneous coronary intervention (PCI). This study was a secondary retrospective analysis involving 2114 ACS patients undergoing PCI at a single center in China. The patients were divided into two groups according to age (premature ACS group: ≤ 55 years in men, ≤ 65 years in women; nonpremature ACS group: > 55 years in men, > 65 years in women). The primary endpoint was all-cause death, and the secondary endpoint was a composite of all-cause death, nonfatal myocardial infarction, nonfatal stroke, target vessel revascularization, and recurrent angina at follow-up, defined as MACEs. The incidence of all-cause death and MACEs was significantly lower in the premature than in the nonpremature ACS group (P < 0.001). Female sex, higher triglyceride levels, and higher low-density lipoprotein cholesterol levels were identified as independent risk factors that accelerated the development of ACS, whereas higher high-density lipoprotein cholesterol levels were identified as protective factors. Furthermore, in patients with premature ACS, non-ST-elevation ACS, cardiac insufficiency, multivessel disease, and left main lesion were risk factors for MACEs. Younger individuals, especially females, are advised to undergo early screening for the risk factors of premature ACS. Primary prevention of dyslipidemia should be more aggressively promoted at a young age. For premature ACS patients undergoing PCI, strengthened management and regular re-examinations are necessary to avoid adverse cardiovascular events as much as possible.

Clinical Outcome of Revascularization Deferral With Instantaneous Wave-Free Ratio and Fractional Flow Reserve: A 5-Year Follow-Up Substudy From the iFR-SWEDEHEART Trial.

Background Although physiology-based assessment of coronary artery stenosis using instantaneous wave-free ratio (iFR) and fractional flow reserve (FFR) are established methods of guiding coronary revascularization, its clinical outcome in long-term deferral needs further evaluation, especially with acute coronary syndrome as a clinical presentation. The aim was to evaluate the long-term clinical outcome of deferral of revascularization based on iFR or FFR. Methods and Results This is a substudy of the iFR-SWEDEHEART (Instantaneous Wave-Free Ratio Versus Fractional Flow Reserve in Patients With Stable Angina Pectoris or Acute Coronary Syndrome) randomized clinical trial, where patients deferred from revascularization from each study arm were selected. Nine hundred eight patients deferred from coronary revascularization with iFR (n=473) and FFR (n=435) were followed for 5 years. The national quality registry, SWEDEHEART (Swedish Web-System for Enhancement and Development of Evidence-Based Care in Heart Disease Evaluated According to Recommended Therapies), was used for patient data collection and clinical follow-up. The end point was major adverse cardiac events and their individual components all-cause death, cardiovascular death, noncardiovascular death, nonfatal myocardial infarction, and unplanned revascularization. No significant difference was found in major adverse cardiac events (iFR 18.6% versus FFR 16.8%; adjusted hazard ratio, 1.08 [95% CI, 0.79-1.48]; P=0.63) or their individual components. Conclusions No differences in clinical outcomes after 5-year follow-up were noted when comparing iFR versus FFR as methods for deferral of coronary revascularization in patients presenting with stable angina pectoris and acute coronary syndrome. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT02166736.

Rota-Lithotripsy as a Novel Bail-Out Strategy for Highly Calcified Coronary Lesions in Acute Coronary Syndrome.

Heavily calcified lesions in acute coronary syndrome (ACS) still represent a challenging subset for percutaneous coronary intervention (PCI). Rota-lithotripsy-a marriage of rotational atherectomy and intravascular lithotripsy-has recently been introduced to clinical practice as a novel therapeutic option. This study is among the to present the 6-month clinical outcomes of rota-lithotripsy when performed in the ACS setting. The study cohort consisted of 15 consecutive ACS patients who underwent a rota-lithotripsy-PCI due to the presence of a highly calcified, undilatable lesion. The procedural success ratio reached 100%. During the 6-month follow-up, in two of the patients, instances of MACE (major adverse cardiac events) occurred, including one fatal event. Additionally, during the observation period, one target lesion failure, due to subacute stent thrombosis, was identified. Rotational atherectomy with the subsequent use of shockwave intravascular lithotripsy appears to be a safe and effective therapeutic bail-out option for the management of highly calcified coronary artery lesions. Despite, these initial favorable outcomes, carrying out a large number of studies with long-term observations is still necessary in order to establish the potential benefits and shortcomings of rota-lithotripsy.

TCT-136 Use of Sirolimus-Coated Balloon in De Novo Small-Vessel Coronary Lesions in Acute Coronary Syndrome: Long-Term Follow-Up From a Single-Center Registry

TCT-136 Use of Sirolimus-Coated Balloon in De Novo Small-Vessel Coronary Lesions in Acute Coronary Syndrome: Long-Term Follow-Up From a Single-Center Registry

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

BackgroundApproximately 50% of the patients undergoing percutaneous coronary intervention (PCI) for acute coronary syndromes (ACS) have additional stenotic lesions in non-infarct-related coronary arteries. The decision whether these stenoses require further treatment is routinely based on angiography alone. The quantitative flow ratio (QFR) is a simple non-invasive method that may help quantify the functional significance of these intermediate coronary artery lesions. The aim of our single-center, randomized superiority trial is to test the impact and efficacy of QFR, as compared to angiography, in the treatment of patients with ACS with multivessel coronary artery disease. Primary goal of the study is to investigate 1. The impact of QFR on the proportion of patients receiving PCI vs. conservative therapy and 2. whether QFR improves angina pectoris and overall cardiovascular outcomes.Methods and AnalysisAfter treatment of the culprit lesion(s), a total of 200 consecutive ACS patients will be randomized 1:1 to angiography- vs. QFR-guided revascularization of non-culprit stenoses. Patients and clinicians responsible are blinded to the randomization group. The primary functional endpoint is defined as the proportion of patients assigned to medical treatment in the two groups. The primary clinical endpoint is a composite of death, non-fatal myocardial infarction, revascularization and significant angina at 12 months. Secondary endpoints include changes in the SAQ subgroups, and clinical events at 3- and 12-month follow-up.DiscussionThis study is designed to investigate whether QFR-based decision-making is associated with a decrease in angina and an improved prognosis in patients with multivessel disease.Trial Registration NumberClinicalTrials.gov Registry (NCT04808310).

Combined Use of Multiple Intravascular Imaging Techniques in Acute Coronary Syndrome.

Recent advances in intravascular imaging techniques have made it possible to assess the culprit lesions of acute coronary syndrome (ACS) in the clinical setting. Intravascular ultrasound (IVUS) is the most commonly used intravascular imaging technique that provides cross-sectional images of coronary arteries. IVUS can assess plaque burden and vessel remodeling. Optical coherence tomography (OCT) is a high-resolution (10 μm) intravascular imaging technique that uses near-infrared light. OCT can identify key features of atheroma, such as lipid core and thin fibrous cap. Near-infrared spectroscopy (NIRS) can detect lipid composition by analyzing the near-infrared absorption properties of coronary plaques. NIRS provides a chemogram of the coronary artery wall, which allows for specific quantification of lipid accumulation. These intravascular imaging techniques can depict histological features of plaque rupture, plaque erosion, and calcified nodule in ACS culprit lesions. However, no single imaging technique is perfect and each has its respective strengths and limitations. In this review, we summarize the implications of combined use of multiple intravascular imaging techniques to assess the pathology of ACS and guide lesion-specific treatment.

Efficacy and Safety of Excimer Laser Catheter in Patient with Complex or High Thrombotic Coronary Artery Stenosis

Background: Indications of excimer laser use in percutaneous coronary intervention (PCI) are uncrossable device after coronary guidewire passing and thrombus modification in Acute Coronary Syndrome lesion (ACS). The excimer laser has been used for more than twenty years. However, there are inconsistent data of the efficacy and safety in an excimer laser use over the drug-eluting stent (DES) era. The authors gathered data of patient that underwent PCI using excimer laser in contemporary PCI strategy. Primary outcome was efficacy of the excimer laser defined as technical success excimer laser. Materials and Methods: The present study was a single-center retrospective analysis of 115 lesions from 112 patients over eight years with 1.1% of all PCI used excimer laser-assisted catheter. The patient data were extracted from hospital-based inpatient and outpatient medical records. A technical success excimer laser was defined as the laser catheter could cross the entire length of the stenotic lesion determined by angiographic evidence of tip catheter beyond lesion or mention in the procedural record. Results: The mean patient age was 67.1 years old with 65.2% being male and 45.2% having diabetes. The average left ventricular ejection fraction (LVEF) was 51.9%. Chronic total occlusion was 39.1% followed by 33.9% of thrombotic lesion. Intravascular imaging was used in 64.4%. Overall technical success of excimer laser was 74.8% with significantly higher success rate in thrombotic groups at 94.9 versus 64.5% (p&lt;0.001). Overall procedural PCI success was 87.8% and no difference was observed between groups at 94.9% versus 84.2% (p=0.135). The slow flow phenomenon was significantly higher in the thrombotic groups at 17.9% versus 2.6% (p=0.007), whereas coronary perforation, major dissection, and death were not different. The authors found that older age such as 80 years or older and non-thrombotic lesions were significantly associated with technical failure of excimer laser use. Conclusion: Excimer laser had a high success rate in the thrombotic lesion and a fair success rate in non-thrombotic lesions. The PCI procedure success was high in both groups Keywords: Excimer laser; Percutaneous coronary intervention; Uncrossable lesion; Adjunctive lesion modification

Optical Coherence Tomography-OCT for Characterization of Non-Atherosclerotic Coronary Lesions in Acute Coronary Syndromes.

Cardiovascular diseases are the main cause of death worldwide, with coronary artery disease being the predominant underlying etiology. The most prevalent coronary lesions are represented by the atherosclerotic plaques, in more than 85% of cases, but there are several other non-atherosclerotic lesions such as spontaneous coronary artery dissection and/or hematoma and spontaneous recanalization of coronary thrombus, which are less common, approximately 5% of cases, but with similar clinical manifestations as well as complications. There are insufficient data regarding the pathological mechanism, true prevalence and optimal treatment of these kind of coronary lesions. Optical coherence tomography (OCT) is an intracoronary imaging technique, developed in order to overcome the diagnostic limitations of a standard coronary angiography and has an extremely high resolution, similar to that of a usual histological evaluation of a biopsy sample, thus, OCT provides a histological-like information, but in a in vivo environment. The aim of this article is to review the current knowledge regarding non-atherosclerotic coronary lesions, with an emphasis on the importance of OCT for optimal identification, characterization of pathogenic mechanisms and optimal treatment selection.

736 Hazy spots: through the eye of optical coherence tomography

Abstract Aims Acute stent thrombosis after coronary artery stent placement is a rare but serious complication in percutaneous coronary intervention (PCI). Stenting culprit lesions in acute coronary syndrome (ACS) has higher risk of acute stent thrombosis than stable coronary artery disease, and many local and systemic factors may contribute to increase this risk. Tissue protrusion (TP), and in particular, plaque prolapse after PCI can play a role in acute stent thrombosis, and intra-vessel imaging is the principal instrument to identify such underlying lumen alteration after stent implantation, and guide intervention. Methods and results We report the case of a 54-year-old man with a history of hypertension, dyslipidemia, type 2 diabetes mellitus, obesity and no other relevant comorbidities in remote history, who underwent a coronary angiography for an unstable angina. A long, calcific sub-occlusion of the left anterior descending artery (LAD), which involved LAD-first diagonal branch (D1) bifurcation (Medina 1.1.1) and LAD-D2 bifurcation (Medina 1.1.0) was found. After deployment of two overlapping drug-eluting stents (DES), (ULTIMASTER TANSEI 3.0 × 38 mm and 3.0 × 21 mm) and struts apposition optimization with sequence of proximal optimization technique (POT) on D1 and D2, and a kissing balloon technique (KS) on LAD-D2 bifurcation, a ‘hazy’ in-stent image was detected right after the LAD-D2 bifurcation, suggesting an acute in-stent thrombosis, in absence of flow alteration (TIMI 3), symptoms or ECG modifications. Multiple thrombus-aspiration were made and resulted in abundant thrombus removal and improvement in the angiographic image, with persistent valid flow on every three vessels (TIMI 3). After 5 days of triple anticoagulant therapy with ticagrelor, cardioaspirin and UFH infusion, he underwent a new coronary angiography control. A similar ‘hazy’ image was detected right after LAD-D2 bifurcation within the LAD. An optical coherence tomography (OCT) pullback was made to assess the nature of the angiographic finding. OCT showed good struts apposition in almost every cross-sectional images, but an evident TP was detected right on the angiographic hazy spot. OCT allowed to evaluate the lipid-richness of the stented plaque and the nature of the TP, which was mixed with evident both white and red thrombus apposition (minimum luminal area measured 4.5 mm2). OCT guided a new PCI, with a stent-in-stent implantation on LAD. TP was absent on the post-PCI OCT run. Conclusions In this report, we showed the usefulness of OCT in revealing a potential high risk thrombogenic source. OCT not only characterized something that angiography alone couldn’t, but suggested the etiology of the amount of thrombus removed by the vessel during the first PCI. Indeed, despite an optimized cycle of anticoagulant therapy, OCT still revealed several mixed thrombus apposition on the TP, and this suggested its role in the acute stent thrombosis. OCT guided the choice to appose a new stent-in-stent to solve a potential thrombogenic source.

Abstract 12211: Water Hammer Shock Causing Rupture Of Vulnerable Cap Of Culprit Lesions In Acute Coronary Syndrome: An Angiographic And Machine Learning Analysis

Introduction: Acute coronary syndrome (ACS) is caused by rupture of coronary plaques. What triggers these ruptures? Hypothesis: In the field of hydraulics, in a setting of a tank and draining pipe, if the valve at the distal end of the pipe is open, the fluid flows normally. If the valve closes abruptly, the flow next to the valve stops. However the fluid from the tank continues to flow forward and can collide with the distal stationary fluid. This is called water hammer shock. Could the same event happen in coronary arteries? The contraction of the left ventricle (LV) is similar to the abrupt closure of a valve, stopping the myocardial capillary flow. Could the systolic LV contraction trigger water hammer shock? Methods: Angiograms with culprit lesions of ACS (recorded at 15 images/second or 0.06 second per image) were reviewed. The first image was of the artery completely filled with contrast. The subsequent images showed the blood in white color blood moving in over a background of black contrast. The normal flow was laminar. When there was retrograde on top of turbulent flow, this was evidence of a collision between antegrade and retrograde flow (or water hammer shock). The measurements by visual angiographic evaluation and by Machine Learning (ML) included (1) the duration and (2) size of coronary segment with turbulence. The ML program had 2 models (build on Python). Model 1 was built based on U-net and Densenet-121 for vessel segmentation. Model 2 was used for classification of flow. The model 2 was trained based on the convolutional neural network. Results: Angiograms of 20 ACS patients showed laminar flow (90%) in diastole. The flow became turbulent during systole with retrograde flow. The area of collision or water hammer shock showed diffuse coarse mixing of black (contrast) and white (blood). The presence of turbulence matched the location of 85% of ruptured plaques. The duration of turbulence lasted 80% of systole. Special protocols were used successfully to train AI to recognize the lesions, retrograde and turbulent flow. Conclusions: With the new angiographic technique, detailed images of water hammer shock matched the location of ruptured plaques in ACS patients. These results may help to understand the genesis and offer precise prevention and treatment for ACS

Coronary lipid-rich plaque characteristics with acute coronary syndrome and chronic coronary syndrome: a near infrared spectroscopy and intravascular ultrasound study

Abstract Background Asians have a much lower incidence of adverse coronary events than Caucasians, and the characteristics of vulnerable plaque might be different among the ethnics. Purpose The aim of this study was to investigate the clinical characteristics of lipid-rich plaque (LRP) in the Asian population and we also aimed to distinguish the characteristics of an acute coronary syndrome (ACS) culprit lesion and a chronic coronary syndrome (CCS) culprit lesion. Furthermore, we evaluated the association between lipid core burden index (LCBI) and cardiovascular risk factors, lipid profiles, and inflammatory biomarkers, as determined in vivo by near infrared spectroscopy intravascular ultrasound (NIRS-IVUS) imaging in patients undergoing percutaneous coronary intervention (PCI). Methods We evaluated 207 patients (ACS, n=75; CCS, n=132) who underwent PCI under NIRS-IVUS. Plaque characteristics and the extent of LRP [defined as a long segment with a 4-mm maximum LCBI (maxLCBI4mm)] on NIRS in de-novo culprit and non-culprit segments were analyzed. Results The mean age was 65 years old and 82% of patients were male. The ACS culprit lesions had a significantly higher maxLCBI4mm (median [interquartile range (IQR)]: 533 [385–745] vs. 361 [174–527], p&amp;lt;0.001) than the CCS culprit lesions. Whereas, no significant difference was seen in maxLCBI4mm between ACS and CCS non-culprit lesion segments (246 [53, 342] vs. 185 [37, 350], p=0.47) (Figure 1). Receiver-operating characteristic analysis showed that the NIRS maxLCBI4mm could distinguish the ACS culprit segment from the CCS culprit segment, with a sensitivity of 73% and a specificity of 69% (c-statistic = 0.69; p&amp;lt;0.001, cut-off value of max LCBI4mm = 408) (Figure 2). On multivariate logistic analysis, a large LRP (defined as maxLCBI4mm ≥400) was the strongest independent predictor of the ACS culprit segment (odds ratio, 3.87; 95% confidence interval, 1.95–8.02). In non-culprit segments, 19.8% of patients had at least one large LRP without a small lumen. No significant correlation was found between the extent of LRP and circulating lipid profiles and inflammatory makers biomarkers (hs-CRP, IL-6, TNF-α) in both the culprit and non-culprit lesion segments, whereas the extent of LRP was positively correlated with IVUS plaque burden (r=0.24, p&amp;lt;0.001). Conclusions We confirmed that NIRS-IVUS plaque assessment could be useful to differentiate ACS from CCS culprit lesions, and that a threshold maxLCBI4mm ≥400 was clinically suitable in Japanese patients. No systemic surrogate markers were found to be associated with the extent of LRP by NIRS in culprit and non-culprit segments. Consequently, we believe that direct intravascular evaluation of coronary plaque characteristics remains important for identification of high-risk LRP. Funding Acknowledgement Type of funding sources: None. Figure 1. The difference of maxLCBI4mmFigure 2. ROC curve

Intravascular ultrasound insights into the unstable features of the coronary atherosclerotic plaques: A systematic review and meta‐analysis

There is a lack of a comprehensive picture of plaque geometry and composition of unstable atherosclerotic lesions as observed with intravascular ultrasound techniques. We analysed through a systematic review with meta-analysis 39 characteristics of atherosclerotic plaques in three scenarios involving culprit and non-culprit lesions from acute coronary syndromes vs stable angina pectoris patients, and culprit vs non-culprit lesions in acute coronary syndromes patients. A systematic search of PubMed and EMBASE, from inception to April 2020 was performed. The combined odds ratios or mean differences of all IVUS characteristics were calculated with random-effects models. Twenty-eight studies involving 5434 subjects, and 5618 lesions were included. Culprit lesions in acute coronary syndromes have larger plaque areas and remodeling indexes (MD=0.13 [0.08; 0.17], p<0.001) and contained larger necrotic cores (MD=0.67 (95% CI 0.19;1.15), p=0.006) that stable angina culprit lesions. In acute patients, culprit plaques were also more remodeled, had larger necrotic cores and had more frequently a Thin-Cap Fibroatheroma morphology (OR=1.79 (95% CI 1.21; 2.65), p=0.004) than non-culprit lesions. Non-culprit lesions in acute syndromes were more often ruptured (OR=2.25 (95% CI:1.05; 4.82), p=0.037) or Thin-Cap Fibroatheromas than in stable angina. Culprit lesions from acute coronary patients are larger, more positively remodeled and contained more lipids as compared to stable angina lesions or non-culprit in acute patients. Non culprit lesions are also more often complicated or vulnerable in acute than stable patients.