Coronary Artery Lumen Research Articles

Prevalence of high-risk plaque features on cardiac computed tomography scans in patients with a coronary artery calcium score of zero

Abstract Introduction Coronary artery calcium (CAC) score of zero (so-called "power of zero") is associated with a very low rate of major adverse cardiac events (MACE), especially during short and midterm follow-up. However, a CAC score of zero does not definitively exclude the presence of atherosclerotic plaques or obstructive coronary artery disease (CAD). The composition of atherosclerotic plaques and the frequency of high-risk plaque features in this population are not well described. Purpose We sought to characterize the composition of atherosclerotic plaques and assess the frequency of high-risk plaque features on contrast-enhanced computed tomography (CT) images in patients with a zero CAC score. Methods The study enrolled patients with stable chest pain suspected of CAD referred for coronary CT imaging and having a CAC score of zero. Coronary CT angiography images were assessed by an expert reader to identify atherosclerotic plaques and high-risk plaque features in all coronary arteries with a diameter ≥1.5mm. The coronary artery lumen and plaques were manually segmented, and the degree of stenosis was evaluated following the Coronary Artery Disease Reporting and Data System (CAD-RADS) criteria. The presence of four high-risk plaque features was identified: positive remodeling, spotty calcification, low-attenuation plaque, and napkin ring sign. Total plaque volume, percent atheroma volume, and plaque composition were quantified using dedicated software (Figure 1). Results A total of 145 patients (mean age 54.2±12.1 years, 35.9% males) were included in the analysis. At least one coronary artery plaque was identified in 30 individuals (20.7%). 22 (15.2%), 7 (4.8%), and 1 (0.7%) patients were categorized into CAD-RADS 1, CAD-RADS 2, and CAD-RADS 3 categories, respectively. Among 30 patients with any coronary artery plaque, at least one high-risk feature was found in 10 individuals (33.3%), while 3 individuals (10.0%) had two features. Positive remodeling was found in 7 (23.3%), spotty calcification in 3 (10.0%), low-attenuation plaque in 3 (10.0%), and napkin ring sign in 0 patients, respectively (Figure 1). The mean total plaque volume was 48.2±54.3mm³, and the mean percent atheroma volume was 1.2±0.8%. Total plaque volume comprised low-attenuation (0.4%), fibro-fatty (58.9%), fibrous (39.4%), and calcified (1.3%) plaque volumes. Notably, in 3 (10.0%) individuals, the presence of calcified plaque was identified, which on non-contrast CT images did not meet the Agatston criteria for the CAC score. Conclusions Our study demonstrates a significant prevalence of atherosclerotic plaques and high-risk plaque features in patients with a CAC score of zero. Specifically, one in every five study participants had identifiable atherosclerotic plaque, with one in every three of those exhibiting one or more high-risk plaque features. The prognostic significance of these findings warrants further evaluation in studies with longitudinal follow-up.

Serial optical coherence tomography assessment of coronary atherosclerosis and long-term clinical outcomes

Abstract Background The impact of high-risk coronary artery plaques identified using optical coherence tomography (OCT) on late luminal narrowing and clinical events remains poorly understood. Methods This multicenter prospective study included 176 patients who underwent percutaneous coronary intervention (PCI) and serial OCT at baseline and 1-year follow-up to investigate non-target regions with angiographically intermediate stenosis. The primary outcome measure was luminal narrowing within the matched regions of interest in the non-target regions over a 1-year period. The secondary outcome measures included all-cause death, cardiac death, nonfatal myocardial infarction, and ischemia-driven coronary artery revascularization within 3 years. Results At 1 year after PCI, the coronary artery lumen area in non-target regions significantly decreased from 6.06 (95% confidence interval [CI], 5.60–6.53) to 5.88 (95% CI, 5.41–6.35) mm2, with a difference of -0.18 (95% CI, -0.22 to -0.14 mm2; P<0.001). This decrease was pronounced in thin-cap fibroatheromas (TCFAs), thick-cap fibroatheromas, mixed plaques, and fibrous plaques. The prevalence of TCFAs decreased from 3.4% to 3.3% (P<0.001), whereas that of thick-cap fibroatheromas also decreased from 35% to 33% (P<0.001). Patients with TCFA had a significantly higher risk of ischemia-driven non-target vessel revascularization (hazard ratio [HR], 2.42; 95% CI, 1.03–5.71; P=0.04), primarily due to revascularization in the imaged region. The higher prevalence of fibroatheroma was associated with a numerically increased risk of imaged region revascularization (HR per 10%, 1.38; 95% CI, 0.97–1.97; P=0.07). The prevalence of coronary artery calcium significantly increased from 31% at baseline to 34% at 1-year follow-up (P<0.001), accompanied by a significant increase in calcium thickness and angle. Diabetes and current smoking habits were independently associated with increasing calcium prevalence. No significant association was observed between the prevalence of coronary artery calcium and clinical outcomes within 3 years. Conclusions Coronary artery lumen area significantly decreased over a 1-year interval, particularly in TCFAs, thick-cap fibroatheromas, mixed plaques, and fibrous plaques. Although no significant association was noted between coronary artery calcium prevalence and clinical outcomes within 3 years, the interaction between calcium progression and long-term clinical events necessitates further investigation.

Impact of ultra-high-resolution on cardiac CT assessment of coronary artery stenoses, plaque burden/composition, and pericoronary adipose tissue attenuation

Abstract Background Conventional coronary computed tomography angiography (CCTA) overestimates stenoses within stents and calcified arteries due to "blooming" artifacts. Ultra-high-resolution coronary CT (UHR-CT) may overcome this limitation because of higher spatial resolution. Purpose To investigate differences in coronary arterial lumen volume, stenosis severity, and plaque composition, between CCTA and UHRCT in patients with stents and/or high coronary calcium scores. Methods As part of a prospective pilot study, 14 patients referred for invasive coronary angiography for evaluation of obstructive CAD underwent UHRCT (Canon Precision, 160 x 0.25mm slices) prior to catheterization. Images of identical cardiac phases were reconstructed in two badges for comparison: 1) Ultra-high resolution using a 1,024 x 1,024 matrix, 0.25 mm, and 2) conventional resolution with a 524 x 524 matrix, 0.5 mm. All images were reconstructed using iterative reconstruction algorithm (AIDR 3D) and a sharp kernel (FC05). For the left main and three coronary arteries, an automated contour analysis using a dedicated software (QAngioCT RE 3.2, Medis, Netherlands) was performed to compare conventional CCTA vs. UHR-CT resolution images across common vascular and plaque metrics, including lumen and vessel volume, plaque burden/volume, plaque composition based upon predefined fixed intensity cut-off values of CT attenuation, minimal and maximal plaque thickness, pericoronary adipose tissue attenuation (PCAT), minimal lumen area and diameter, and diameter stenosis. All lumen and vessel contours were generated by the software, without manual editing. The segment model proposed by the SCCT was used as reference and the lesions classified as greater than 25% stenosis by visual assessment were recorded. The quality of the images was subjectively assessed using a 5-point Likert scale. Vessel segments with scores 1 (severe artifacts) and 2 (pronounced artifacts) were not included in the analysis. Results The mean patient age was 68.5 years (±6.8), 2 were female (14.3%), 6 patients had stents (11 stented segments) and the mean Agatston score was 947.6 (±449) among the 8 non-stented patients. A total of 56 vessels, 133 segments, and 57 lesions were analyzed. Eight segments (6%) were excluded from the analysis due to poor quality. Results on a per segment and per lesion basis were summarized in the table. The mean PCAT value was significantly lower for the UHRCT images compared to NR reconstruction in both segment (p<0.001) and lesion based (p=0.002) analyses. Plaque differentiation varied by UHRCT resulted in a lower fibrous plaque volumes but higher necrotic (low attenuation) plaque volumes. Conclusions Ultra-high-resolution CT image analysis results in significantly different coronary artery plaque volume and PCAT assessment vs. conventional resolution CCTA. These findings have implications for evaluating high-risk plaque features and perivascular inflammation in patients.Table 1

Serial Optical Coherence Tomography Assessment of Coronary Atherosclerosis and Long-Term Clinical Outcomes.

The impact of high-risk coronary artery plaques identified using optical coherence tomography on late luminal narrowing and clinical events remains poorly understood. This multicenter prospective study included 176 patients who underwent percutaneous coronary intervention and serial optical coherence tomography at baseline and 1-year follow-up to investigate nontarget regions with angiographically intermediate stenosis. At 1 year after percutaneous coronary intervention, the coronary artery lumen area decreased significantly from 6.06 (95% CI, 5.60-6.53) mm2 to 5.88 (95% CI, 5.41-6.35) mm2 (difference, -0.18; 95% CI, -0.22 to -0.14 mm2; P<0.001), particularly in thin-cap fibroatheromas, thick-cap fibroatheromas, mixed plaques, and fibrous plaques. The prevalence of fibroatheroma decreased from 38% to 36% (P<0.001), whereas calcified plaque increased from 31% to 34% (P<0.001), accompanied by a significant increase in calcium thickness and angle. Diabetes and current smoking habits were independently associated with increasing calcium prevalence. Patients with thin-cap fibroatheroma had a significantly higher 3-year risk of ischemia-driven nontarget vessel revascularization (hazard ratio, 2.42 [95% CI, 1.03-5.71]; P=0.04), primarily due to revascularization in the imaged region. No significant association was observed between coronary artery calcium prevalence and clinical outcomes within 3 years. The coronary artery lumen area significantly decreased over a 1-year interval, particularly in thin-cap fibroatheromas, thick-cap fibroatheromas, mixed plaques, and fibrous plaques. Although thin-cap fibroatheroma prevalence was associated with higher risk of ischemia-driven nontarget vessel revascularization, no significant association was noted between coronary artery calcium prevalence and clinical outcomes within 3 years. The interaction between calcium progression and long-term clinical events necessitates further investigation. URL: https://www.umin.ac.jp/ctr/; Unique Identifier: UMIN000031937.

The effect of the liposomal form of alteplase on the effectiveness of thrombolysis in coronary arteries in acute myocardial infarction

A liposomal (Lip) formulation of tissue plasminogen activator, alteplase (AlT), has been developed. The quantitative and qualitative composition of the liposomes, as well as their physicochemical properties and proteolytic activity, have been studied in relation to the thrombolytic liposomal form. It was determined that a formulation consisting of liposomes with a phosphatidylcholine/cholesterol ratio of 1.5 : 1, and lipids/alteplase ratio of 1 : 1, is optimal for treating acute myocardial infarction (AMI) in experimental models. At different component ratios, liposomes had a negative zeta potential value greater than 30 mV, indicating their aggregative stability, even after storage for two days at 20 degrees Celsius. Liposomes derived from soy phosphatidylcholine showed greater colloidal stability with a zeta potential of approximately –57 mV and a lower hydrodynamic diameter of approximately 140 nanometers, compared to liposomes derived from egg phosphatidylcholine, which had a zeta potential around –35.4 mV and a hydrodynamic diameter around 220 nanometers. The initial content of free AlT in the liposome supernatant from egg phosphatidylcholine (Lipeg) was 15.0 ± 4.0 %. During the incubation period of 4 days, the concentration of free AlT decreased to 9.0 ± 4.5 %. In contrast, in liposomes derived from soy phosphatidylcholine (LipS), the content of free AlT increased from 11.0 ± 4.5 % to 32.5 ± 6.0 % over the same incubation period. The value of the proteolytic activity of tissue plasminogen activator (tPA) in the compositions of Lipeg(AlT) and Lips (AlT) depends on the type of phosphatidylcholine. The initial tPA activity in Lipeg (AlT) was 36.0 %, and after 1 day, it increased to 45 %. In Lips (AlT), the initial activity was 61.0 % and increased to 66 % after 1 day. When using the liposomal form of alteplase for delivery into the coronary arteries of rats with acute myocardial infarction (AMI), a more complete fibrin lysis is noted compared to animals receiving the native form of the drug. The developed system of targeted delivery of alteplase using soy liposomes has been shown to significantly improve the degree of coronary artery lumen restoration by more than 15 %, compared to the use of a conventional drug (p &lt; 0.05).

Influence of the pressure wire on the fractional flow reserve calculation: CFD analysis of an ideal vessel and clinical patients with stenosis

Background and objectiveFractional Flow Reserve (FFR) is generally considered the gold standard in hemodynamics to assess the impact of a stenosis on the blood flow. The standard procedure to measure involves the displacement of a pressure guide along the circulatory system until it is placed next to the lesion to be analyzed. The main objective of the present study is to analyze the influence of the pressure guide on the invasive FFR measurements and its implications in clinical practice. MethodsWe studied the influence of pressure wires on the measurement of Fractional Flow Reserve (FFR) through a combination of Computational Fluid Dynamics (CFD) simulations using 45 clinical patient data with 58 lesions and ideal geometries. The analysis is conducted considering patients that were subjected to a computer tomography and also have direct measurements using a pressure guide. Influence of the stenosis severity, degree of occlusion and blood viscosity has also been studied. ResultsThe influence of pressure wires specifically affects severe stenosis with a lumen diameter reduction of 50 % or greater. This type of stenosis leads to reduced hyperemic flow and increased coronary pressure drop. Thus, we identified that the placement of wires during FFR measurements results in partial obstruction of the coronary artery lumen, leading to increased pressure drop and subsequent reduction in blood flow. The severity of low FFR values associated with severe stenosis may be prone to overestimation when compared to stenosis without severe narrowing. These results have practical implications, particularly in the interpretation of lesions falling within the “gray zone” (0,75−0,80). ConclusionsThe pressure wire's presence significantly alters the flow on severe lesions, which has an impact on the FFR calculation. In contrast, the impact of the pressure wire appears to be reduced when the FFR is larger than 0.8. The findings provide critical information for physicians, emphasizing the need for cautious interpretation of FFR values, particularly in severe stenosis. It also offers insights into improving the correlation between FFRct models and invasive measurements by incorporating the influence of pressure wires.

PON1 rs662, rs854560 and TRIB1 rs17321515, rs2954029 Gene Polymorphisms Are Associated with Lipid Parameters in Patients with Unstable Angina.

Acute coronary heart disease (CHD) is mainly caused by the rupture of an unstable atherosclerotic plaque. Many different factors can cause stenosis or even occlusion of the coronary artery lumen, such as vasculitis and platelet aggregation. Our study was performed to assess the association between PON1 rs662, rs854560 and TRIB1 rs17321515, rs2954029 polymorphisms and the risk of CHD, as well as the association between studied polymorphisms and selected clinical parameters affecting the risk of developing ischemic heart disease. A total of 232 patients with unstable angina were enrolled in this study. There were no statistically significant differences in the PON1 rs662, rs854560 and TRIB1 rs17321515, rs2954029 polymorphism distributions between the total study and control groups. Total cholesterol plasma levels were significantly higher in patients with the PON1 rs662 TT genotype compared to those with the CC+TC genotypes, as well as in patients with the PON1 rs854560 TT genotype compared to those with the AA+AT genotypes. LDL plasma levels were significantly increased in patients with the PON1 rs854560 TT genotype compared to those with the AA+AT genotypes. Plasma levels of HDL were significantly decreased in patients with the TRIB1 rs17321515 AA+AG genotypes compared to those with the GG genotype, as well as in patients with the TRIB1 rs2954029 AA+AT genotypes compared to those with the TT genotype. Our results suggest that the analysed polymorphisms are not risk factors for unstable angina in the Polish population. However, the results of this study indicate an association between the PON1 rs662, rs854560 and TRIB1 rs17321515, rs2954029 polymorphisms with lipid parameters in patients with coronary artery disease.

Quantitative analysis of blooming artifact caused by calcification based on X-ray energy difference using computed tomography

Blooming artifacts caused by calcifications appearing on computed tomography (CT) images lead to an underestimation of the coronary artery lumen size, and higher X-ray energy levels are suggested to reduce the blooming artifacts with subjective visual assessment. This study aimed to evaluate the effect of higher X-ray energy levels on the quantitative measurement of adjacent pixels affected by calcification using CT images. In this two-part study, CT images were acquired from dual-energy CT scanners by changing the X-ray energy levels such as kilovoltage peak (kVp) and kilo-electron volts (keV). Adjacent pixels affected by calcification were measured using the brightened length, excluding the actual calcified length, as determined by the full width at third maximum. In a separate clinical study, the adjacent affected pixels associated with 23 calcifications across 10 patients were measured using the same method as that used in the phantom study. Phantom and clinical studies showed that the change in kVp (field of view [FOV] 300 mm: p = 0.167, 0.494, and 0.861 for vendors 1, 2, and 3, respectively) and keV levels (p = 0.178 for vendor 2) failed to reduce the adjacent pixels affected by calcification, respectively. Moreover, the change in keV levels showed different aspects of adjacent pixels affected by calcification in the phantom study (FOV 300 mm: no significant difference [p = 0.191], increase [p < 0.001], and decrease [p < 0.001] for vendors 1, 2, and 3, respectively). Quantitative measurements revealed no significant relationship between higher X-ray energy levels and the adjacent pixels affected by calcification.

Automatic Coronary Artery Plaque Quantification and CAD-RADS Prediction Using Mesh Priors.

Coronary artery disease (CAD) remains the leading cause of death worldwide. Patients with suspected CAD undergo coronary CT angiography (CCTA) to evaluate the risk of cardiovascular events and determine the treatment. Clinical analysis of coronary arteries in CCTA comprises the identification of atherosclerotic plaque, as well as the grading of any coronary artery stenosis typically obtained through the CAD-Reporting and Data System (CAD-RADS). This requires analysis of the coronary lumen and plaque. While voxel-wise segmentation is a commonly used approach in various segmentation tasks, it does not guarantee topologically plausible shapes. To address this, in this work, we propose to directly infer surface meshes for coronary artery lumen and plaque based on a centerline prior and use it in the downstream task of CAD-RADS scoring. The method is developed and evaluated using a total of 2407 CCTA scans. Our method achieved lesion-wise volume intraclass correlation coefficients of 0.98, 0.79, and 0.85 for calcified, non-calcified, and total plaque volume respectively. Patient-level CAD-RADS categorization was evaluated on a representative hold-out test set of 300 scans, for which the achieved linearly weighted kappa ( κ ) was 0.75. CAD-RADS categorization on the set of 658 scans from another hospital and scanner led to a κ of 0.71. The results demonstrate that direct inference of coronary artery meshes for lumen and plaque is feasible, and allows for the automated prediction of routinely performed CAD-RADS categorization.

Impact of Slow Deep Breathing Exercises using Incentive Spirometry on Functional Capacity among Patients with Coronary Artery Disease

Introduction A condition known as coronary artery disease occurs when the myocardium does not receive enough blood or oxygen. It is caused by blockage of the coronary arteries and is characterized by an imbalance in the supply and demand of oxygen. Usually, it involves blood flow obstruction caused by plaques that form in the coronary artery lumen. It is the leading global cause of death. Methods Participants in this quasi-experimental research design included patients with coronary artery diseases. Patients with severe respiratory conditions, a history of coughing, difficulty breathing deeply, non-pulmonary status at first examination, and inability to complete the study were among the exclusion criteria. the participants in the study were 50 samples (25 research groups and 25 control groups), the research groups were given an incentive spirometer in addition to hands-on instruction on how to use it and collect accurate measurements. Patients were told to lie down or sit in order to breathe in and out through the tube 10 times. Patients were instructed to do this exercise three times every eight hours for a duration of three weeks. Findings: Three weeks following the intervention, a re-assessment of the functional capacity, revealed an improvement in factional capacity solely in the study groups relative to the pre-test. Conclusion Using an innovative spirometer, the study demonstrated the impact of various deep breaths on the functional capacity of patients with CAD. Nearly all patients demonstrated a significant short-term improvement in their functional capacity, and no significant side effects were found. Consequently, this methodology can be applied in subsequent research to examine long-term impacts for weeks or months. Because it is simple to use and the measurement is non-intrusive, this method is perfect for self-monitoring at home.

Rapid automated lumen segmentation of coronary optical coherence tomography images followed by 3D reconstruction of coronary arteries.

Optical coherence tomography has emerged as an important intracoronary imaging technique for coronary artery disease diagnosis as it produces high-resolution cross-sectional images of luminal and plaque morphology. Precise and fast lumen segmentation is essential for efficient OCT morphometric analysis. However, due to the presence of various image artifacts, including side branches, luminal blood artifacts, and complicated lesions, this remains a challenging task. Our research study proposes a rapid automatic segmentation method that utilizes nonuniform rational B-spline to connect limited pixel points and identify the edges of the OCT lumen. The proposed method suppresses image noise and accurately extracts the lumen border with a high correlation to ground truth images based on the area, minimal diameter, and maximal diameter. We evaluated the method using 3300 OCT frames from 10 patients and found that it achieved favorable results. The average time taken for automatic segmentation by the proposed method is 0.17s per frame. Additionally, the proposed method includes seamless vessel reconstruction following the lumen segmentation. The developed automated system provides an accurate, efficient, robust, and user-friendly platform for coronary lumen segmentation and reconstruction, which can pave the way for improved assessment of the coronary artery lumen morphology.

Immunomodulatory Mechanism of Coronary Heart Disease and Related Therapeutic Applications and Prospects

Coronary heart disease is a type of heart disease caused by stenosis or occlusion of the coronary artery lumen. The typical symptoms are chest pain, chest tightness, and aggravation after activity. It is divided into two categories, chronic coronary disease (CAD) and acute coronary syndrome (ACS). The pathological basis of CHD is coronary atherosclerosis, immune factors (cellular immunity, humoral immunity, autoimmunity, complement system, cytokines, adhesion molecules and apoptosis, etc.) are involved in the formation and development of atherosclerosis. So far, its pathogenesis has not been fully understood and there is no effective and specific drug treatment in clinic. This article is based on existing literature and research on the impact of immune regulation on coronary heart disease. To investigate the role of the immune system in the treatment of atherosclerosis, we analyzed the causes of atherosclerosis. Through literature search, this paper found the influence of infectious, autoimmune and chemical factors on atherosclerosis, and sought corresponding treatment methods for the cardiovascular and cerebrovascular injuries caused by these factors.

Strategy of delayed intervention without stent implantation in myocardial infarction with ST segment elevation caused by massive thrombosis of the infarct-related artery

Aim. TIntroduction. To evaluate in-hospital angiographic and five-year posthospital clinical outcomes of percutaneous intervention strategy without stent implantation with immediate coronary artery stenting technique in STEMI patients with massive coronary thrombosis.Material and methods. The study enrolled 116 patients with primary STEMI myocardial infarction with the signs of massive thrombosis in the lumen of the main epicardial coronary artery with TIMI thrombus grade greater than 3 after antegrade blood flow restoration. In the 1st group of delayed intervention at the primary stage the blood flow was restored by small diameter balloon inflation and/ or manual vacuum thrombus aspiration until stable TIMI grade 3 blood flow was achieved, at control CAG on day 5-6 in 36 people the stent was not implanted due to insignificance of infarct-related coronary artery stenosis (stenosis less than 50% according to QCA). Immediate stent implantation was performed in 78 patients (group 2). The primary endpoint was the incidence of adverse cardiovascular events, including total mortality, recurrent myocardial infarction, repeated revascularization of the infarct-responsive artery. Secondary endpoint: frequency of achieving optimal myocardial perfusion as measured by angiography – TIMI blood flow and Myocardial Blush Grade.Results. The median follow-up period was 47 months. The incidence of the primary end point (MACE) was 15,8% in group 1 and 23,1% in group 2, with no statistically significant difference (p=0,408). Overall mortality (10,5% and 11,7%), the rate of repeat myocardial infarction (2,6% and 5,1%), and the rate of repeat target vessel revascularization (2,6% and 6,4%) were without significant advantage between subgroups. Optimal reperfusion (TIMI-3 and Myocardial Blush Grade 2-3 after primary procedure was achieved in significantly (p=0,02) more patients in group 1 (89%) than in group 2 (69,2%) ST segment resolution ≥70% after intervention was achieved in 87% of cases in group 1 and in 64,1% of cases in group 2 (p=0,011).Conclusion. In STEMI patients with massive coronary thrombosis, the method of delayed percutaneous intervention increases the rate of achieving optimal blood flow and allows avoiding stent implantation in the infarct-related artery in 50% of cases as compared to the method of immediate stenting. Both methods have comparable hospital and five-year clinical risks.

Ultra-High-Resolution Electrocardiography Enables Earlier Detection of Transmural and Subendocardial Myocardial Ischemia Compared to Conventional Electrocardiography.

The sensitivity of exercise ECG is marginally sufficient for the detection of mild reduction of coronary blood flow in patients with early coronary atherosclerosis. Here, we describe the application of a new technique of ECG registration/analysis-ultra-high-resolution ECG (UHR ECG)-for early detection of myocardial ischemia (MIS). The utility of UHR ECG vs. conventional ECG (C ECG) was tested in anesthetized rats and pigs. Transmural MIS was induced in rats by the ligation of the left coronary artery (CA). In pigs, subendocardial ischemia of a variable extent was produced by stepwise inflation of a balloon within the right CA, causing a 25-100% reduction of its lumen. In rats, a reduction in power spectral density (PSD) in the high-frequency (HF) channel of UHR ECG was registered at 60 s after ischemia (power 0.81 ± 0.14 vs. 1.25 ± 0.12 mW at baseline, p < 0.01). This was not accompanied by any ST segment elevation on C ECG. In pigs, PSD in the HF channel of UHR ECG was significantly decreased at a 25% reduction of CA lumen, while the ST segment on C ECG remained unchanged. In conclusion, UHR ECG enabled earlier detection of transmural MIS compared to C ECG. PSD in the HF channel of UHR ECG demonstrated greater sensitivity in the settings of subendocardial ischemia.

Management of a rare isolated left main coronary artery ostial stenosis in a young patient: a case report

BackgroundIsolated congenital ostial stenosis of the left coronary artery (LCA) is extremely rare, and available literature is limited. Long-term treatment success is key in the choice of treatment strategy due to the mostly young age of the patients. Here, we present a clinical case and shed light on the surgical treatment strategies including their pitfalls.Case presentationWe describe a 20-year-old male who presented to the emergency department with recurrent typical angina pectoris symptoms (CCS class II). Computed tomography and coronary angiography revealed isolated ostial stenosis of the LCA, with prominent collaterals from the right coronary artery. The patient was operated on and intra-operative findings showed a severely narrowed LCA ostium that appeared to be fibrotic, and to originate from a similarly fibrotic left coronary sinus of the aortic root. The LCA was excised from the left coronary sinus, and trimmed until the coronary artery lumen appeared macroscopically normal. The fibrotic left coronary sinus was resected and replaced with a bovine pericardial patch, into which the coronary artery was re-inserted. During weaning from cardiopulmonary bypass, we faced a diminished left ventricular function. We attributed this to insufficient myocardial protection. Isolated antegrade cardioplegia had been used, which, for technical reasons, had to be administered separately to the right and left coronary artery after aortotomy. In the setting of huge collaterals from the right to the left coronary artery, a steal-effect likely occurred. After prolonged reperfusion, the left ventricular function recovered, and the further post-operative course was unremarkable.ConclusionsFor the surgical treatment of congenital ostial stenosis of the LCA, both ostium reconstruction and coronary artery bypass grafting have been described. The advantage of ostium reconstruction as chosen here is to create a physiological flow and supply situation to the affected myocardial areas. Furthermore, in case of other downstream events, such as the development of coronary artery disease, all further therapeutic options are preserved.Special attention should be paid to the administration of cardioplegia in these patients. Combined ante and retrograde cardioplegia administration probably would have achieved more extensive myocardial protection in our case.

Accuracy of IVUS-Based Machine Learning Segmentation Assessment of Coronary Artery Dimensions and Balloon Sizing

BackgroundAccurate intravascular ultrasound (IVUS) measurements are important in IVUS-guided percutaneous coronary intervention optimization by choosing the appropriate device size and confirming stent expansion. ObjectivesThe purpose of this study was to assess the accuracy of machine learning (ML) automatic segmentation of coronary artery vessel and lumen dimensions and balloon sizing. MethodsUsing expert analysis as the gold standard, ML segmentation of 60 MHz IVUS images was developed using 8,076 IVUS cross-sectional images from 234 patients, which were randomly split into training (83%) and validation (17%) data sets. The performance of ML segmentation was then evaluated using an independent test data set (437 images from 92 patients). The endpoints were the agreement rate between ML vs experts’ measurements for appropriate balloon size selection, and lumen and acute stent areas. Appropriate balloon size was determined by rounding down from the mean vessel diameter or rounding up from the mean lumen diameter to the next balloon size. The difference of lumen area ≥0.5 mm2 was considered as clinically significant. ResultsML model segmentation correlated well with experts’ segmentation for training data set with a correlation coefficient of 0.992 and 0.993 for lumen and vessel areas, respectively. The agreement rate in lumen and acute stent areas was 85.5% and 97.0%, respectively. The agreement rate for appropriate balloon size selection was 70.6% by vessel diameter only and 92.4% by adding lumen diameter. ConclusionsML model IVUS segmentation measurements were well-correlated with those of experts and selected an appropriate balloon size in more than 90% of images.

Impaired retinal microcirculation in patients with non-obstructive coronary artery disease.

To quantitatively investigate alterations of retinal microcirculation in patients with non-obstructive coronary artery disease (NOCAD) using optical coherence tomography angiography (OCTA), and to identify the ability of retinal microcirculation parameters in differentiating coronary artery disease (CAD) subtypes. All participants with angina pectoris underwent coronary computed tomography angiography. Patients with lumen diameter reduction of 20-50% in all major coronary arteries were defined as NOCAD, while patients with at least one major coronary artery lumen diameter reduction ≥ 50% were recruited as obstructive coronary artery disease (OCAD). Participants without a history of ophthalmic or systemic vascular disease were recruited as healthy controls. Retinal neural-vasculature was measured quantitatively by OCTA, including peripapillary retinal nerve fiber layer (RNFL) thickness and vessel density (VD) of the optic disc, superficial vessel plexus (SVP), deep vessel plexus (DVP), and foveal density (FD 300). p<0.017 is considered significant in multiple comparisons. A total of 185 participants (65 NOCAD, 62 OCAD, and 58 controls) were enrolled. Except for the DVP fovea (p=0.069), significantly reduced VD in all other regions of SVP and DVP was detected in both the NOCAD and OCAD groups compared to control group (all p<0.017), while a more significant decrease was found in OCAD compared to NOCAD. Multivariate regression analysis showed that lower VD in superior hemi part of whole SVP (OR: 0.582, 95% CI: 0.451-0.752) was an independent risk factor for NOCAD compared to controls, while lower VD in the whole SVP (OR: 0.550, 95% CI: 0.421-0.719) was an independent risk factor for OCAD compared to NOCAD. Using the integration of retinal microvascular parameters, the area under the receiver operating characteristic curve (AUC) for NOCAD versus control and OCAD versus NOCAD were 0.840 and 0.830, respectively. Significant retinal microcirculation impairment, while milder than that in OCAD was observed in NOCAD patients, indicating retinal microvasculature assessment might provide a new systemic microcirculation observation window for NOCAD. Furthermore, retinal microvasculature may serve as a new indicator to assess the severity of CAD with good performance of retinal microvascular parameters in identifying different CAD subtypes.

Pregnancy-related spontaneous coronary artery dissection: a rare cause of acute coronary syndrome in the third trimester

BackgroundSpontaneous Coronary Artery Dissection (SCAD) is a rare cause of myocardial infarction and sudden cardiac death that is mostly seen in younger patients without significant cardiac risk factors. The mechanism by which SCAD causes an acute coronary event is related to the compromise of the coronary artery lumen as a result of hematoma within the vessel wall. In comparison to their non-pregnant counterparts, when SCAD is associated with pregnancy, it has been associated with an increased risk of life-threatening arrhythmias, cardiogenic shock, and death. The underlying mechanism behind SCAD is not yet fully understood, and despite the condition’s high mortality rate, it remains underdiagnosed.Case PresentationOur case features a 38-year-old woman at 29 weeks of gestation presenting with chest pain that persisted despite initial management. Coronary angiography revealed a Type 2a spontaneous dissection of the left anterior descending artery. Given the risks of percutaneous coronary intervention in SCAD management and overall clinical stability, the patient was treated with conservative management.ConclusionSCADs are a rare cause of acute coronary syndrome that can be found in patients without any prior cardiac risk factors. It is important to have a high index of suspicion when diagnosing SCADs given, they can cause life-threatening arrhythmias, cardiogenic shock, and death. This case highlights considerations that must be taken into account when treating P-SCAD, as opposed to SCAD in the postpartum period.

Characteristics and Pattern of Calcified Nodule and/or Nodular Calcification Detected by Intravascular Ultrasound on the Device-Oriented Composite Endpoint (DoCE) in Patients with Heavily Calcified Lesions Who Underwent Rotational Atherectomy-Assisted Percutaneous Coronary Intervention.

This study aimed to determine characteristics and pattern of a calcified nodule (CN) and/or nodular calcification (NC) detected by intravascular ultrasound (IVUS) on the device-oriented composite endpoint (DoCE) in patients with calcified lesions who underwent rotational atherectomy (RA)-assisted percutaneous coronary intervention (PCI). The characteristics and pattern of a CN and/or NC on clinical outcome remain unknown. We retrospectively enrolled patients who underwent RA-assisted PCI at Siriraj Hospital during August 2016 to April 2020. Preprocedural IVUS imaging was mandatory. CN/NC was defined as convex shape of luminal surface and luminal side of calcium with protrusion into the coronary artery lumen as assessed by IVUS. The primary outcome was cumulative of DoCE, defined as the composite of cardiovascular death, myocardial infarction, and clinically-driven target lesion revascularization. Two hundred patients were included. Primary outcome occurred in 14%. The cumulative DoCE was significantly higher in the CN/NC group than that in the non-CN/NC group (20.7% vs. 8.8%, p = 0.022). CN/NC (p = 0.023) and MSA ≤ 5.5 mm2 (p = 0.047) were correlated with a significantly higher cumulative DoCE. CN/NC was the independent predictor for the cumulative DoCE (HR = 2.96, 95% CI 1.08-8.11, p = 0.035). Pattern and characteristic of CN/NC have a prognostic value. Patients with an eccentric CN/NC had a significantly higher cumulative DoCE compared to those CN/NC with concentric calcification (p = 0.014). The presence of a CN/NC in patients with heavily calcified lesions who underwent RA-assisted PCI was found to be associated with increased cumulative 5 year DoCE, especially in patients with an eccentric CN/NC. The clinical trial is registered with TCTR20210616001.

TGF-β1 and TGFβR2 Gene Polymorphisms in Patients with Unstable Angina.

Acute coronary syndromes result from a sudden reduction in the lumen of a coronary artery as a result of atherosclerotic plaque rupture, its swelling or the formation of thrombotic lesions. Many mediators with inflammatory, prothrombotic and proatherogenic effects have been shown to be involved, including numerous cytokines, chemokines, adhesion molecules and growth factors. TGF-β1 is a pleiotropic cytokine found in various cells that regulates cell growth, differentiation and matrix production. The aim of our study was to assess the association between polymorphisms in the TGF-β1 gene (rs1800469, rs1800470) and polymorphisms in the TGFBR2 receptor gene (rs6785358, rs9838682) and the risk of unstable angina, as well as selected clinical parameters affecting the risk of ischemic heart disease. The study included 232 patients with unstable angina. The diagnosis of unstable angina was made by typical clinical presentation and confirmation of significant coronary artery lumen stenosis (&gt;70%) during coronary angiography. There were no statistically significant differences in the distribution of TGFBR2 rs6785358 and rs9838682 genotypes and haplotypes between patients with unstable angina and control subjects. We observed increased values of plasma total and LDL cholesterol levels, as well as triglycerides, in patients with the TGFBR2 rs9838682 AA genotype. In patients with the TGFBR2 rs6785358 AA genotype, we noted increased BMI values. There were no statistically significant associations between other studied polymorphisms and clinical parameters. Polymorphisms in the TGF-β1 gene (rs1800469, rs1800470) and polymorphisms in the TGFBR2 receptor gene (rs6785358, rs9838682) are not significant risk factors for unstable angina in our population. The TGFBR2 gene rs9838682 polymorphism may influence the lipid parameters in patients with coronary artery disease.