Circumflex Coronary Artery Research Articles

Ventricular injury in acute left circumflex occlusion: Exploration using precordial bipolar leads and regional VECTORCARDIOGRAMS

BackgroundPrecordial Bipolar Leads (PBLs) provide new electrocardiographic information derived from standard 12‑lead ECG recordings. ObjectivesTo explore the usefulness of PBLs in patients with acute circumflex coronary artery (CxCA) occlusion. MethodsTwelve patients undergoing elective percutaneous transluminal coronary angioplasty (PTCA) were studied before and after acute CxCA occlusion and their data were processed with new methods based on PBLs. ResultsThe findings were: 1. In right PBL V2-V1, a strong systolic current of injury moving in the left-to-right direction coexists with a strong right-to-left current of injury displayed in left standard unipolar precordial leads (V4, V5 and V6). 2. Ischemic changes lead to a significant increase (approximately 10 ms) in the QRS duration in different leads, although changes in the QRS loop rotation and folding were absent. 3. In the transverse, sagittal, and frontal planes, superimposing two PBLs and the corresponding Regional VCG facilitates the location of the J-point. 4. In the Regional VCGs of this group of patients, J-point and ST segment shifts produced an image that reminds the Greek letter omega (Ω). 5. The currents of injury flowing in opposite directions could result in electrical cancellation that minimizes ECG changes in the standard 12‑lead recordings. ConclusionsComputerized processing of digital, standard 12‑lead ECG recordings, provides new valuable diagnostic data in patients with acute CxCA occlusion. The loops revealed important information related to systolic currents of injury. Because these methods use routine 12‑lead ECG data, the procedure is based only in software applications. Condensed abstractTwelve patients undergoing PTCA were studied before and after acute CxCA occlusion and their data were processed with the new methods based on Precordial Bipolar Leads (PBLs) to explore their usefulness.The results showed strong systolic currents of injury in different and sometimes opposite directions in the right-to-left axis and ischemic alterations in the time and amplitude of the QRS waves. The superimposition of two-dimensional coordinates planes (x-y, x-z or z-y) helped to locate the J-point and to display the Regional VCG omega sign (Ω) of myocardial injury. In conclusion, computerized processing of digital ECG data provides new diagnostic information in patients with acute CxCA occlusion.

Myocardial deformation characteristics assessed by cardiovascular magnetic resonance feature tracking in a healthy Chinese population

PurposeTo explore global/regional myocardial deformation across various layers, vascular distributions, specific levels and distinct walls in healthy individuals using cardiovascular magnetic resonance feature tracking (CMR-FT). MethodsWe selected a cohort of 55 healthy participants and CMR cine images were used to obtain the left ventricular (LV) peak longitudinal, circumferential, radial strains (LS, CS, RS). The characteristics of normal LV strain in various layers (endocardium, myocardium, epicardium), territories [left anterior descending artery (LAD), left circumflex artery (LCX), and right coronary artery (RCA)], levels (basal, middle, apical) and walls (anterior, septum, inferior, lateral) were compared. ResultsThe absolute values of the LV global LS and CS gradually decreased from endocardium to epicardium. The absolute LV global RS (65.7 ± 47.7%) was maximum relative to LS (−22.0 ± 10.8%) and CS (−22.8 ± 7.7%). The absolute values of the LCX territorial strain were the largest compared with the LAD and RCA territorial strains. Regional RS, endo-CS and endo-LS gradually increased from the basal to the apical level. The LV lateral walls had the highest strain values (CS, LS, and RS). ConclusionsVariations in normal LV strain values across various layers, territories, levels, and walls were observed, suggesting the necessity for careful clinical interpretation of these strain values. These findings also partially revealed the complexity of normal cardiac mechanics.

Abstract P391: Case Review of Congenital Ectopic Coronary Artery Disease

Coronary artery anomalies (CAAs), rare congenital conditions affecting approximately 1% of adults, are associated with adverse cardiac events, including sudden cardiac death. This article reviews three recent clinical cases involving CAAs, delving into their origins, clinical presentations, diagnostics, treatments, and outcomes. CAAs involve irregularities in coronary artery origin, distribution, and termination. Notably, the left coronary artery arising from the right sinus (0.15%) and the right coronary artery from the left sinus (0.92%) are common variations. Other anomalies include the left circumflex artery (LCX) originating from the right coronary sinus and the left main coronary artery or Left anterior descending artery (LAD) emerging from opposite sinuses, leading to diverse clinical presentations. Case 1 features a 70-year-old female with hypertension presenting with exertional angina. Surgical revascularization was performed after coronary angiography revealed an ectopic LAD. In Case 2, a 72-year-old male with hypertension presented with chest pain and NSTEMI. Coronary angiography showed an ectopic LCX and significant stenosis in LAD and RCA, treated with PCI. Case 3, involving a 49-year-old female with hypertension and syncope, was managed medically as angiography revealed an anomalous RCA origin without significant obstructive disease. Treatment approaches for CAAs are patient-specific due to limited guidelines. Case 1 underwent coronary artery bypass surgery, Case 2 received PCI, and Case 3 was treated medically. Diagnostic methods encompass stress testing, coronary angiography, and coronary CT angiography (CCTA). CCTA is particularly valuable for distinguishing benign and clinically significant ectopic origins. For intramural courses, coronary unroofing is the preferred surgical technique, while absent intramural courses may require coronary translocation or reimplantation.Percutaneous coronary intervention (PCI) primarily addresses downstream atherosclerotic lesions without directly addressing the CAA. Treatment choice depends on patient-specific risk factors and pathology. In summary, CAAs pose challenges in interventional cardiology, warranting early and accurate diagnosis to prevent adverse events. A personalized approach, considering patient characteristics, is crucial due to the lack of robust guidelines. Advanced imaging technologies like CCTA and MRA aid in assessing CAAs' clinical significance and guiding treatment decisions. Further research is required to establish optimal treatment strategies, including investigating CAAs' prevalence in specific regions such as Arkansas.Top of Form Bottom of Form

Design of experiment approach to identify the dominant geometrical feature of left coronary artery influencing atherosclerosis

Background and Objective. Coronary artery geometry heavily influences local hemodynamics, potentially leading to atherosclerosis. Consequently, the unique geometrical configuration of an individual by birth can be associated with future risk of atherosclerosis. Although current researches focus on exploring the relationship between local hemodynamics and coronary artery geometry, this study aims to identify the order of influence of the geometrical features through systematic experiments, which can reveal the dominant geometrical feature for future risk assessment. Methods. According to Taguchi’s method of design of experiment (DoE), the left main stem (LMS) length (l LMS), curvature (k LMS), diameter (d LMS) and the bifurcation angle between left anterior descending (LAD) and left circumflex (LCx) artery (α LAD-LCx) of two reconstructed patient-specific left coronary arteries (LCA) were varied in three levels to create L9 orthogonal array. Computational fluid dynamic (CFD) simulations with physiological boundary conditions were performed on the resulting eighteen LCA models. Average helicity intensity (h 2) and relative atheroprone area (RAA) of near-wall hemodynamic descriptors were analyzed. Results. The proximal LAD (LAD proximal) was identified to be the most atheroprone region of the left coronary artery due to higher h 2, large RAA of time averaged wall shear stress (TAWSS < 0.4 Pa), oscillatory shear index (OSI ∼ 0.5) and relative residence time (RRT > 4.17 Pa−1). In both patient-specific cases, based on h 2 and TAWSS, d lms is the dominant geometric parameter while based on OSI and RRT, α LAD-LCx is the dominant one influencing hemodynamic condition in proximal LAD (p < 0.05). Based on RRT, the rank of the geometrical factors is: α LAD-LCx > d LMS > l LMS > k LMS, indicating that α LAD-LCx is the most dominant geometrical factor affecting hemodynamics at proximal LAD which may influence atherosclerosis. Conclusion. The proposed identification of the rank of geometrical features of LCA and the dominant feature may assist clinicians in predicting the possibility of atherosclerosis, of an individual, long before it will occur. This study can further be translated to be used to rank the influence of several arterial geometrical features at different arterial locations to explore detailed relationships between the arterial geometrical features and local hemodynamics.

Study on the related factors of TCM constitution and hemodynamics in patients with coronary heart disease.

The concepts of "individualization" and "preventive treatment" should be incorporated into the precise diagnosis and treatment of coronary heart disease (CHD). Both hemodynamics and Chinese medicine constitution studies align with these two concepts. This study utilized data from 81 patients with CHD, including 12 patients with balanced constitution (BC), 20 patients with blood stasis constitution (BSC), 17 patients with phlegm-dampness constitution (PDC), 15 patients with qi-deficiency constitution (QDC), and 17 patients with other constitutions. Clinical data provided information on the patients' blood property, heart function, degree of coronary stenosis, coronary hemodynamics, and so on. These parameters were compared between patients with balanced constitution vs. biased constitutions as well as between those with blood stasis constitution, phlegm-dampness constitution, and qi-deficiency constitution. Compared to biased constitution (BC), patients with balanced constitution exhibited lower total cholesterol (TC) levels and low-density lipoprotein (LDL) levels. Additionally, they had lighter stenosis degrees in the Left anterior descending branch (LAD) and Left circumflex branch (LCX) branches. The hemodynamic condition of the LAD and LCX was better for those with balanced constitution; however there was no difference in heart function. Among the groups categorized by blood stasis, phlegm dampness or qi deficiency constituions, patients classified under phlegm dampness had higher levels of LDL compared to those classified under blood stasis or qi deficiency, while patients classified under qi deficiency had higher levels of blood glucose compared to those classified under blood stasis or phlegm dampness. Hemodynamic environments also differed among the LAD and LCX for each group but there were no significant differences observed in heart function or degree of coronary stenosis among these three groups. The balanced constitution demonstrates superior blood property, degree of coronary artery stenosis, and coronary hemodynamics compared to the biased constitution. Furthermore, among the three constitutions with CHD, variations in blood property and certain hemodynamic parameters are observed. These findings emphasize the significant clinical value of incorporating physical factors into the diagnosis and treatment of patients with CHD.

Cardiac tamponade due to coronary artery injury after left upper lobectomy

BackgroundCardiac tamponade caused by coronary artery injury is an extremely rare postlobectomy complication. Herein, we present a case of cardiac tamponade due to coronary artery injury after a left upper lobectomy for lung cancer and discuss the possible cause of coronary artery injury.Case presentationAn 82-year-old man with atrial fibrillation, emphysema, chronic heart failure-associated cardiomegaly, and a history of aortic stenting for an abdominal aortic aneurysm underwent a left upper lobectomy without mediastinal nodal dissection for lung cancer. Twenty-eight hours postoperatively, he lost consciousness and went into shock vitals; computed tomography revealed cardiac tamponade. Emergency surgery was performed, which revealed a left circumflex artery laceration. Although the laceration was successfully repaired, he had a gastrointestinal perforation and developed septic shock. He died 35 days after the lung surgery. Intraoperative injury to the heart cannot be ruled out, but the site of the coronary artery injury was located far from the hilum outside the surgical field during the lobectomy. Three-dimensional computed tomography showed that the site of injury was close to the multiple firing junction of the staples that divided the anterior interlobar fissure. Two staples at the multiple firing junction, which protruded perpendicularly to the cut surface, could injure the coronary artery.ConclusionAlthough we cannot rule out the possibility that the intraoperative manipulation procedures contributed to the coronary artery injury, we speculate that the protruding staples might penetrate the pericardium after lung expansion and eventually injured the coronary artery.

Proteomic Profiling of SGLT-2 Inhibitor Canagliflozin in a Swine Model of Chronic Myocardial Ischemia.

Sodium-glucose cotransporter-2 (SGLT2) inhibitors are known to be cardioprotective independent of glucose control, but the mechanisms of these benefits are unclear. We previously demonstrated improved cardiac function and decreased fibrosis in a swine model of chronic myocardial ischemia. The goal of this study is to use high-sensitivity proteomic analyses to characterize specific molecular pathways affected by SGLT-2 inhibitor canagliflozin (CAN) therapy in a swine model of chronic myocardial ischemia. Chronic myocardial ischemia was induced in sixteen Yorkshire swine via the placement of an ameroid constrictor to the left circumflex coronary artery. After two weeks of recovery, swine received either 300 mg of CAN daily (n = 8) or a control (n = 8). After five weeks of therapy, the group of swine were euthanized, and left ventricular tissue was harvested and sent for proteomic analysis. Total proteomic analysis identified a total of 3256 proteins between the CAN and control groups. Three hundred and five proteins were statistically different. This included 55 proteins that were downregulated (p < 0.05, fold change <0.5) and 250 that were upregulated (p < 0.05, fold change >2) with CAN treatment. Pathway analysis demonstrated the upregulation of several proteins involved in metabolism and redox activity in the CAN-treated group. The CAN group also exhibited a downregulation of proteins involved in motor activity and cytoskeletal structure. In our swine model of chronic myocardial ischemia, CAN therapy alters several proteins involved in critical molecular pathways, including redox regulation and metabolism. These findings provide additional mechanistic insights into the cardioprotective effects of canagliflozin.

Establishment and verification of a nomogram that predicts the risk for coronary slow flow.

Coronary slow flow (CSF) has gained significance as a chronic coronary artery disease, but few studies have integrated both biological and anatomical factors for CSF assessment. This study aimed to develop and validate a simple-to-use nomogram for predicting CSF risk by combining biological and anatomical factors. In this retrospective case-control study, 1042 patients (614 CSF cases and 428 controls) were randomly assigned to the development and validation cohorts at a 7:3 ratio. Potential predictive factors were identified using least absolute shrinkage and selection operator regression and subsequently utilized in multivariate logistic regression to construct the nomogram. Validation of the nomogram was assessed by discrimination and calibration. N-terminal pro brain natriuretic peptide, high density lipoprotein cholesterol, hemoglobin, left anterior descending artery diameter, left circumflex artery diameter, and right coronary artery diameter were independent predictors of CSF. The model displayed high discrimination in the development and validation cohorts (C-index 0.771, 95% CI: 0.737-0.805 and 0.805, 95% CI: 0.757-0.853, respectively). The calibration curves for both cohorts showed close alignment between predicted and actual risk estimates, demonstrating improved model calibration. Decision curve analysis suggested high clinical utility for the predictive nomogram. The constructed nomogram accurately and individually predicts the risk of CSF for patients with suspected CSF and may be considered for use in clinical care.

Electrocardiographic patterns and clinical outcomes of acute coronary syndrome cardiogenic shock in patients undergoing percutaneous coronary intervention — A propensity score analysis

ObjectivesTo determine the influence of presenting electrocardiographic (ECG) changes on prognosis in acute coronary syndrome cardiogenic shock (ACS-CS) patients undergoing percutaneous coronary angiography (PCI). BackgroundThe effect of initial ECG changes such as ST-elevation myocardial infarction (STEMI) versus non-STEMI among patients ACS-CS on prognosis remains unclear. MethodsWe analysed data from consecutive patients with ACS-CS enrolled in the Victorian Cardiac Outcomes registry between 2014 and 2020. Inverse probability of treatment weighting analysis (IPTW) was used to assess the effect of ECG changes on 30-day mortality. ResultsOf 1564 patients with ACS-CS who underwent PCI, 161 had non-STEMI and 1403 had STEMI on ECG. The mean age was 66 ± 13 years, and 74 % (1152) were males. Patients with non-STEMI compared to STEMI were older (70 ± 12 vs 65 ± 13 years), had higher rates of diabetes (34 % vs 21 %), prior coronary artery bypass graft surgery (14 % vs 3.3 %), peripheral arterial disease (10.6 % vs 4.1 %, p < 0.01), and lower baseline eGFR (53.8 [37.1, 75.4] vs 65.3 [46.3, 87.8] ml/min/1.73m2), all p ≤ 0.01. Non-STEMI patients were more likely to have a culprit left circumflex artery (29 % vs 20 %) and more often underwent multivessel percutaneous coronary intervention (30 % vs 20 %) but had lower rates of out-of-hospital cardiac arrest (21 % vs 39 %), all p ≤ 0.01. Propensity score analysis with IPTW confirmed that non-STEMI ECG was associated with lower odds for 30-day all-cause mortality (OR 0.47 [0.32, 0.69], p < 0.001), and 30-day major adverse cardiovascular and cerebrovascular events (OR 0.48 [0.33, 0.70]). ConclusionsIn patients undergoing PCI, Non-STEMI as compared to STEMI on index ECG was associated with approximately half the relative risk of both 30-day mortality and 30-day MACCE and could be a useful variable to integrate in ACS-CS risk scores.

Sodium valproate treatment reverses endothelial dysfunction in aorta from rabbits with acute myocardial infarction

Sodium valproate (VPA), a histone deacetylase (HDAC) inhibitor, could be a promising candidate to treat acute myocardial infarction (AMI). In this study, AMI was induced in New Zealand White rabbits by occluding the left circumflex coronary artery for 1 h, followed by reperfusion. The animals were distributed into three experimental groups: the sham-operated group (SHAM), the AMI group and the AMI + VPA group (AMI treated with VPA 500 mg/kg/day). After 5 weeks, abdominal aorta was removed and used for isometric recording of tension in organ baths or protein expression by Western blot, and plasma for the determination of nitrate/nitrite (NOx) levels by colorimetric assay. Our results indicated that AMI induced a reduction of the endothelium-dependent response to acetylcholine without modifying the endothelium-independent response to sodium nitroprusside, leading to endothelial dysfunction. VPA treatment reversed AMI-induced endothelial dysfunction and even increased NO sensitivity in vascular smooth muscle. This response was consistent with an antioxidant effect of VPA, as it was able to reverse the superoxide dismutase 1 (SOD 1) down-regulation induced by AMI. Our experiments also ruled out that the VPA mechanism was related to eNOS, iNOS, sGC and arginase expression or changes in NOx plasma levels. Therefore, we conclude that VPA improves vasodilation by increasing NO bioavailability, likely due to its antioxidant effect. Since endothelial dysfunction was closely related to AMI, VPA treatment could increase aortic blood flow, making it a potential agent in reperfusion therapy that can prevent the vascular damage.

Impact of Incomplete Revascularization After PCI in Left Main Disease: The EXCEL Trial.

The importance of complete revascularization after percutaneous coronary intervention (PCI) in patients with left main coronary artery disease is uncertain. We investigated the clinical impact of complete revascularization in patients with left main coronary artery disease undergoing PCI in the EXCEL trial (Evaluation of XIENCE Versus Coronary Artery Bypass Surgery for Effectiveness of Left Main Revascularization). Composite rates of death or myocardial infarction (MI) following PCI during 5-year follow-up were examined in 903 patients based on core laboratory definitions of anatomic and functional complete revascularization, residual SYNTAX score (The Synergy Between Percutaneous Coronary Intervention With Taxus and Cardiac Surgery), and residual Jeopardy Score (rJS). The risk of death or MI did not vary based on anatomic, functional, or residual SYNTAX score complete revascularization but did differ according to the rJS (5-year rates 17.6%, 19.5%, and 38.9% with rJS 0, 2, and ≥4, respectively; P=0.006). The higher rate of death or MI with rJS≥4 versus rJS≤2 was driven conjointly by increased mortality (adjusted hazard ratio, 2.29 [95% CI, 1.11-4.71]; P=0.02) and spontaneous MI (adjusted hazard ratio, 2.89 [95% CI, 1.17-7.17]; P=0.02). The most common location for untreated severe stenoses in the rJS≥4 group was the left circumflex artery (LCX), and the post-PCI absence, compared with the presence, of any untreated lesion with diameter stenosis ≥70% in the LCX was associated with reduced 5-year rates of death or MI (18.9% versus 35.2%; hazard ratio, 0.48 [95% CI, 0.32-0.74]; P<0.001). The risk was the highest for residual ostial/proximal LCX lesions. Among patients undergoing PCI in EXCEL trial, incomplete revascularization according to the rJS was associated with increased rates of death and spontaneous MI. Post-PCI untreated high-grade lesions in the LCX (especially the ostial/proximal LCX) drove these outcomes. URL: https://www.clinicaltrials.gov; Unique identifier: NCT01205776.

Ventricular tachycardia ablation after myocardial infarction guided by cardiac magnetic resonance/multidetector computed tomography image integration

Abstract INTRODUCTION The persistent challenge of ventricular tachycardia (VT) ablation lies in the elevated morbidity and mortality due to the underlying disease progression and the complexity of the arrhythmogenic substrate. As imaging methods are evolving, substrate-based VT ablation is moving closer to the realm of precision medicine. CASE PRESENTATION A 52-year-old patient with a history of hypertension, type II diabetes mellitus, hyperlipidemia, and stage IIIB chronic kidney disease was referred to our hospital for sustained monomorphic VT. Upon admission, the patient was hemodynamically stable. Laboratory results indicated mild anemia, moderate renal dysfunction, and normal myocardial enzymes. ECG during sinus rhythm showed widespread repolarization abnormalities in the apical and postero-lateral leads. Echocardiography revealed mild left ventricular dysfunction and coronary angiography confirmed significant lesions in multiple coronary arteries that were treated with drug-eluting stents (DES). Cardiac MRI showed relatively limited areas of old myocardial infarctions in the left circumflex artery and left anterior descending artery territories, therefore we decided to perform VT ablation. We used a Carto 3 Biosense Webster electro-anatomical mapping system (EAM) guided by fusion imaging (cardiac MRI and multidetector computed tomography - MDCT) with the aid of ADAS 3D software. The voltage map created during sinus rhythm, was concordant with the lesions identified on LGE-CMR. Radiofrequency (RF) catheter ablation targeted abnormal signals from the EAM, which were identified based on conduction channels (CCs) from the fusion imaging. There was complete VT non-inducibility at programmed ventricular stimulation (PVS). At the 3-month follow-up, echocardiography showed a slight improvement in LVEF and repeated PVS proved persistent ventricular arrhythmia non-inducibility. CONCLUSION Substrate-based VT ablation in structural heart disease has greatly improved by high-resolution substrate imaging with detailed anatomy, allowing successful personalized treatment. There is room for further improvement in the near future with the contribution of artificial intelligence, possibly with a more targeted and automated VT ablation.

DPP-4 inhibitor sitagliptin treatment results in altered myocardial metabolic proteome and oxidative phosphorylation in a swine model of chronic myocardial ischemia.

Small animal models have shown improved cardiac function with DPP-4 inhibition, but many human studies have shown worse outcomes or no benefit. We seek to bridge the gap by studying the DPP-4 inhibitor sitagliptin in a swine model of chronic myocardial ischemia using proteomic analysis. Thirteen Yorkshire swine underwent the placement of an ameroid constrictor on the left coronary circumflex artery to model chronic myocardial ischemia. Two weeks post-op, swine received either sitagliptin 100 mg daily (SIT, n = 5) or no drug (CON, n = 8). After 5 weeks of treatment, swine underwent functional measurements and tissue harvest. In the SIT group compared to CON, there was a trend towards decreased cardiac index (p = 0.06). The non-ischemic and ischemic myocardium had 396 and 166 significantly decreased proteins, respectively, in the SIT group compared to CON (all p < 0.01). This included proteins involved in fatty acid oxidation (FAO), myocardial contraction, and oxidative phosphorylation (OXPHOS). Sitagliptin treatment resulted in a trend towards decreased cardiac index and decreased expression of proteins involved in OXPHOS, FAO, and myocardial contraction in both ischemic and non-ischemic swine myocardium. These metabolic and functional changes may provide some mechanistic evidence for outcomes seen in clinical studies.

Sheath Tip Radial Artery Disruption as a Mechanism for Forearm Hematoma: Insights from the Distal Radial Artery Approach

Abstract Introduction Radial artery occlusion (RAO), Forearm Hematoma (FH), and compartmental syndrome are three well-recognized complications associated with radial artery (RA) access to percutaneous coronary intervention (PCI). There are disparate ways the RA can be damaged, from multiple needling attempts to adverse interactions between the radial sheath, exchange wire, and diagnostic or guiding catheter with the artery. Case presentation We describe a 49-year-old man who had PCI through his right distal RA (dRA) with a straightforward needle puncture, followed by placement of a Terumo® 10cm 6Fr Glidesheath Slender™. After primary PCI to the right coronary artery, right FH developed, but there was neither swelling at the dRA area nor in the hand. He had staged PCI to the left circumflex artery a few days later, and a radial arteriogram was performed using the same access site. This revealed a “circumferential dissection” in the RA, which was likely to have been caused by the tip of the initial radial sheath. Conclusion Hypothetically, the radial sheath can systematically traumatize the RA. It may be the common denominator for RA disruption, RA thrombosis, RAO, FH, and compartmental syndrome in a continuum. Urgent radial arteriography, whenever post-procedural FH is detected, allows for the source of forearm bleeding to be determined and addressed. Trialing this strategy against current watchful conservative management is warranted.

Hemodynamics in left coronary artery with ramus intermedius: A patient-specific computational study

Clinical studies based on coronary computed tomography angiography (CCTA) images suggest that the presence of ramus intermedius (RI) in the left coronary artery (LCA) may aggravate the atherosclerotic depositions in the furcation region. In this study, computational fluid dynamics simulations are performed in patient-specific coronary models consisting of bifurcating LCA and two models having trifurcating LCA. Three-dimensional patient-specific coronary models are constructed from CCTA images obtained from North Eastern Indira Gandhi Regional Institute of Health and Medical Sciences, Shillong, India. Results indicate that the flow redistribution happens in the left coronary branch due to the presence of RI and the flow to left anterior descending artery (LAD) is reduced significantly. Recirculation and flow separation regions are observed in the proximal parts of the LAD and left circumflex artery for trifurcation geometries. The qualitative and quantitative analysis of wall shear stress-based descriptors suggests that the presence of the intermediate branch may affect the atherosusceptibility of the proximal region of LAD. The study indicates that the presence of RI may act as a contributing factor for plaque development and progression in the furcation region and proximal parts of LAD.

Anomalous Origin of the Left Coronary Artery from the Pulmonary Artery Diagnosed in Adulthood

Introduction: An anomalous left coronary artery from the pulmonary artery (ALCAPA) is a rare heart malformation, with 90% of patients dying during the first year of life. If the right coronary artery compensation and multiple collateral circulation are sufficiently established, the patient's myocardial ischemia symptoms are mild and appear later, which is called the adult type ALCAPA. Case Description: A 42-year-old woman presented to our hospital with one-month history of the aggravation of active shortness of breath which gradually progressed to nocturnal paroxysmal shortness of breath and cough. Admission physical examination suggested mild edema of both lower limbs. Transthoracic echocardiography (TTE) showed that a small vessel shadow was abnormally connected to the pulmonary artery (PA), and moderate pulmonary artery hypertension. Coronary computed tomography angiography (CTA) showed an anomalous origin of the left main coronary artery (LMCA) dividing into the left anterior descending (LAD) and left circumflex (LCX) artery from the PA, with no clear connection to the left coronary sinus. The right coronary artery (RCA) was significantly dilated and originated from the normal Valsalva sinus. It was accompanied by multiple collateral circulations, most of which traveled anterior to the right ventricular free wall and anterior interventricular sulcus, and some emanated from the posterior descending branch of the posterior interventricular sulcus and walked toward the posterolateral wall of the left ventricle. Conclusion: Coronary computed tomography angiography (CTA) can be used to visualize the abnormal origin and distribution of the coronary artery's course and may be the first choice in the diagnosis of ALCAPA.

Long-term all-cause death prediction by coronary, aortic, and valvular calcification in patients with acute ST-segment elevation myocardial infarction.

To determine the prognostic value of cumulative calcification score of coronary artery calcification (CAC), thoracic aortic calcification (TAC) and aortic valve calcification (AVC) in acute ST segment elevation myocardial infarction (STEMI) patients. This was a retrospective, single-center cohort study. A total of 332 STEMI patients who received primary percutaneous coronary intervention (PPCI) were enrolled in this study between January 2010 to October 2018. We assessed the calcification in the left anterior descending branch (LAD), left circumflex branch (LCX), right coronary artery (RCA), thoracic aorta, and aortic valve. Calcification of each part was counted as 1 point, and the cumulative calcification score was calculated as the sum of all points. The primary endpoint was all-cause mortality. Multivariate Cox proportional hazards models were used to determine association of cumulative calcification score with end points. The performance of the score was evaluated by receiver operating characteristic (ROC) curve analysis and absolute net reclassification improvement (NRI), compared with the Global Registry of Acute Coronary Events (GRACE) risk score. The overall population's calcification score was 2.0 ± 1.6. During a mean follow-up time of 69.8 ± 29.3 months, the all-cause mortality rate was 12.1%. Kaplan-Meier curve showed that the score was significantly associated with mortality (log-rank p < 0.001). The multivariable Cox proportional hazard analyses showed that a calcification score of 4-5 was independently associated with all-cause death in STEMI patients [hazard ratio (HR) = 2.32, 95% confidence interval (CI): 1.01-5.31, p = 0.046]. The area under the ROC curve (AUC) of the calcification score was 0.67 (95% CI: 0.61-0.72), and the AUC of the GRACE score was 0.80 (95% CI: 0.75-0.84). There was no statistical difference in the predictive value between both scores for 3-year mortality in STEMI patients after PPCI (p = 0.06). Based on the NRI analysis, the calcification score showed better risk classification compared with the GRACE score (absolute NRI = 6.63%, P = 0.027). The cumulative calcification score is independently associated with the long-term prognosis of STEMI patients after PPCI.

Feasibility of Low-Dose and Low-Contrast Media Volume Approach in Computed Tomography Cardiovascular Imaging Reconstructed with Model-Based Algorithm.

Aim: To evaluate the dose reduction and image quality of low-dose, low-contrast media volume in computed tomography (CT) examinations reconstructed with the model-based iterative reconstruction (MBIR) algorithm in comparison with the hybrid iterative (HIR) one. Methods: We prospectively enrolled a total of 401 patients referred for cardiovascular CT, evaluated with a 256-MDCT scan with a low kVp (80 kVp) reconstructed with an MBIR (study group) or a standard HIR protocol (100 kVp-control group) after injection of a fixed dose of contrast medium volume. Vessel contrast enhancement and image noise were measured by placing the region of interest (ROI) in the left ventricle, ascending aorta; left, right and circumflex coronary arteries; main, right and left pulmonary arteries; aortic arch; and abdominal aorta. The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were computed. Subjective image quality obtained by consensus was assessed by using a 4-point Likert scale. Radiation dose exposure was recorded. Results: HU values of the proximal tract of all coronary arteries; main, right and left pulmonary arteries; and of the aorta were significantly higher in the study group than in the control group (p < 0.05), while the noise was significantly lower (p < 0.05). SNR and CNR values in all anatomic districts were significantly higher in the study group (p < 0.05). MBIR subjective image quality was significantly higher than HIR in CCTA and CTPA protocols (p < 0.05). Radiation dose was significantly lower in the study group (p < 0.05). Conclusions: The MBIR algorithm combined with low-kVp can help reduce radiation dose exposure, reduce noise, and increase objective and subjective image quality.

Differentiation of acute coronary syndrome with radiomics of pericoronary adipose tissue.

To assess the potential values of radiomics signatures of pericoronary adipose tissue (PCAT) in identifying patients with acute coronary syndrome (ACS). In total, 149, 227, and 244 patients were clinically diagnosed with ACS, chronic coronary syndrome (CCS), and without coronary artery disease (CAD), respectively, and were retrospectively analysed and randomly divided into training and testing cohorts at a 2:1 ratio. From the PCATs of the proximal left anterior descending branch, left circumflex branch, and right coronary artery (RCA), the pericoronary fat attenuation index (FAI) value and radiomics signatures were calculated, among which features closely related to ACS were screened out. The ACS differentiation models AC1, AC2, AC3, AN1, AN2, and AN3 were constructed based on the FAI value of RCA and the final screened out first-order and texture features, respectively. The FAI values were all higher in patients with ACS than in those with CCS and no CAD (all P < .05). For the identification of ACS and CCS, the area-under-the-curve (AUC) values of AC1, AC2, and AC3 were 0.92, 0.94, and 0.91 and 0.91, 0.86, and 0.88 in the training and testing cohorts, respectively. For the identification of ACS and no CAD, the AUC values of AN1, AN2, and AN3 were 0.95, 0.94, and 0.94 and 0.93, 0.87, and 0.89 in the training and testing cohorts, respectively. Identification models constructed based on the radiomics signatures of PCAT are expected to be an effective tool for identifying patients with ACS. The radiomics signatures of PCAT and FAI values are expected to differentiate between patients with ACS, CCS and those without CAD on imaging.

Evaluation of Canine Shoulder Arthroscopy for Anatomical and Safety Considerations.

Arthroscopy is a well-established diagnostic modality for various orthopaedic conditions in veterinary medicine. The aim of this study was to describe the relationship of canine shoulder arthroscopy portals to major muscular, ligamentous, and neurovascular structures for anatomical and safety considerations. Arthroscopic exploration of 20 adult canine cadaver shoulders was performed. Each shoulder region was dissected layer by layer to the level of the joint. Musculotendinous, ligamentous, and cartilaginous lesions were documented. The distance was measured from each portal to neurovascular structures encountered. Muscular lesions included the deltoideus, cleidobrachialis, omotransversarius, supraspinatus, infraspinatus, and teres minor muscles. The neurovascular structures identified were the omobrachial vein, the caudal circumflex humeral artery, axillobrachial vein, and branches of the axillary nerve. Lesions to the lateral glenohumeral ligament were noted from the caudal instrument portal and the middle arthroscope portal. Iatrogenic articular cartilage injuries were identified on the caudal humeral head and the glenoid. This study supports the safety of lateral shoulder arthroscopy in dogs. Most local neurovascular structures are unaffected with traditional scope portal positions. Musculotendinous lesions are unavoidable due to the extensive muscling surrounding the shoulder but are unlikely to cause severe complications postoperatively.