Coronary thrombo-embolic events after Covid-19 vaccination- a single centre study

Thrombo-embolic complications after Corona virus disease-19 (COVID-19) vaccination have been previously reported. We aimed to study the coronary thrombo-embolic complications (CTE) after COVID-19 vaccination in a single centre during the initial 3 months of vaccination drive in India. All patients admitted to our hospital between 1st March 2021 and 31st May 2021 with Acute coronary syndrome (ACS) were included.Of the 89 patients [Age 55 (47–64)y, 13f] with ACS and angiographic evidence of coronary thrombus, 37 (42%) had prior vaccination history. The timing from last vaccination dose to index event was <1, 1–2, 2–4 and >4 weeks in 9(24%), 4(11%), 15(41%) and 9 (24%) respectively. ChAdOx1 nCoV-19/AZD1222 (Covishield) was the most used vaccine- 28 (76%), while 9 (24%) had BBV152 (Covaxin). Baseline characteristics were similar in both vaccinated (VG) and non-vaccinated group (NVG), except for symptom to door time [8.5 (5.75–14) vs 14.5 (7.25–24) hrs, p = 0.003]. Thrombocytopenia was not noted in any of the VG patients, while 2 (3.8%) of NVG patient had thrombocytopenia (p = 0.51). The pre- Percutaneous Coronary Intervention (PCI) Thrombolysis in Myocardial Infarction (TIMI) flow was significantly lower [1 (0–3) vs2 (1–3), p = 0.03) and thrombus grade were significantly higher [4 (2.5–5) vs 2 (1–3), p = 0.0005] in VG. The in-hospital (2.7% vs 1.9%, p = 1.0) and 30-day mortality were also similar (5.4% vs 5.8%, p = 1.0).This is the first report of CTE after COVID-19 vaccination during the first 3 months of vaccination drive in India. We need further reports to identify the incidence of this rare but serious adverse events following COVID-19 vaccination.     

接受机械取栓治疗的急性脑梗死患者血栓特征研究进展

急性脑梗死是威胁我国人民健康的重大疾病,其致死率及致残率均较高,造成了沉重的社会负担。及时开通导致梗死的责任血管以恢复脑灌注是治疗该病的关键。机械取栓技术的应用使得患者的血栓组织能够被获取并得到研究。本文介绍了近年来通过机械取栓术获取的血栓的相关研究发现,以纤维蛋白为主的血栓是造成取栓困难的重要组织学原因,影像学方法可以在术前评估血栓特征。这些发现提示临床工作者可以积极开发新型血栓取出装置用于处理难治性血栓,并有必要探索精确便捷的血栓特征影像学评价方法,从而提高机械取栓疗效。     

Predictors of Left Atrial Thrombi and Spontaneous Echocardiographic Contrast in the Acute Phase After Cardioembolic Stroke in Patients With Atrial Fibrillation

Introduction: The underlying mechanism of the residual left atrial thrombus (LAT)/spontaneous echo contrast (SEC) after the onset of cardioembolic stroke (CES) is unknown. This study aims to investigate the utility of CHADS₂ and CHA₂DS₂-VASc scores for predicting LAT/SEC, and to investigate the risk factors of residual LAT/SEC after CES onset. Methods: This retrospective study included 124 patients who were admitted with the acute phase of CES at our center. The clinical, echocardiographic variables, the CHADS₂/CHA₂DS₂-VASc scores, and National Institutes of Health Stroke Scale score were retrospectively assessed on admission. Results: Of 124 patients, LAT or SEC was detected in 39 patients (31.5%, 17 LAT and 38 SEC). Univariate analysis showed that the LAT/SEC group had a higher prevalence of nonparoxysmal atrial fibrillation (AF), left ventricular (LV) hypertrophy, hypertension, the rate of anticoagulation before admission, higher National Institutes of Health Stroke Scale score, larger left atrial diameter, and elevated E wave. In contrast, the CHADS₂ and CHA₂DS₂-VASc scores were not associated with LAT/SEC. LAT/SEC was associated with nonparoxysmal AF and LV hypertrophy on multivariate analysis. Moreover, all patients were divided into 4 groups based on the combination between non-paroxysmal AF and LV hypertrophy. The rate of LAT/SEC was the highest (87.5%) in patients with nonparoxysmal AF and LV hypertrophy. Conclusions: Nonparoxysmal atrial fibrillation and left ventricular hypertrophy were associated with residual left atrial thrombus/spontaneous echo contrast in the acute phase after cardioembolic stroke that was independent of the CHADS₂ and CHA₂DS₂-VASc scores.     

心肌超声造影在心脏占位性病变诊断中的价值

心脏占位性病变是一类发病率较低,严重威胁患者生命的疾病,其临床表现缺乏特异性,治疗和预后更因性质而异,因此早期发现及诊断心脏占位性病变对患者非常重要。心肌超声造影是近年来兴起的新技术,该技术能定性及定量评估心脏占位性病变的血流灌注,为诊断及鉴别心脏占位性病变提供依据。本文就心肌超声造影在心脏占位性病变诊断中的价值进行综述。     

The relation between aortic arch branching types and the location of large vessel occlusion in cardioembolic stroke

Cardiac embolism is the leading etiology of ischemic strokes. There are arguments about the left–right propensity of cardioembolic strokes. This study aimed to reveal the relationship between the different aortic arch types and the location of large vessel occlusion (LVO) in cardioembolic stroke. We retrospectively identified all patients with acute ischemic stroke admitted to our comprehensive stroke center who had medium- to high-risk cardioembolic sources according to the TOAST classification. Only those with LVO and available images of the aortic arch were included. Patients were classified into 3 groups according to the aortic arch types: Type I (n = 44), Type II (n = 105), Type III (n = 36). The thrombus was divided into large thrombus or small thrombus based on the location of LVO. Overall, left-sided strokes (50.8%) were almost equal to right-sided (49.2%). There was a growing tendency for the percentage of left-sided infarcts with advancement of the aortic arch types either in the total cases or in the atrial fibrillation cases, with no statistical difference between the 3 aortic arch types. In type III aortic arch, left-sided strokes (69.0%) were twice than right-sided (31%) in large thrombus (P < 0.05), while right-sided strokes (85.7%) were more common than left-sided (14.3%) in small thrombus (P < 0.05). Conversely, in type Ⅰ and II aortic arches, left-sided strokes were more common than right-sided in small thrombus, while right-sided strokes were more common than left-sided in large thrombus (P < 0.05). The left–right propensity of cardioembolic stroke is related to the proximity of clot lodging in different aortic arch types.     

Real‐Time Observation of Thrombus Growth Process in an Impeller of a Hydrodynamically Levitated Centrifugal Blood Pump by Near‐Infrared Hyperspectral Imaging

Understanding the thrombus formation in cardiovascular devices such as rotary blood pumps is the most important issue in developing more hemocompatible devices. The objective of this study was to develop a hyperspectral imaging (HSI) method to visualize the thrombus growth process within a rotary blood pump and investigate the optical properties of the thrombus. An in vitro thrombogenic test was conducted using fresh porcine blood and a specially designed hydrodynamically levitated centrifugal blood pump with a transparent bottom. The pump rotating at 3000 rpm circulated the blood at 1.0 L/min. The bottom surface of the pump was illuminated with white light pulsed at the same frequency as the pump rotation, and the backward‐scattered light was imaged using the HSI system. Using stroboscopic HSI and an image construction algorithm, dynamic spectral imaging at wavelengths ranging from 608 to 752 nm within the rotating pump was achieved. After completing the experiment, we collected the red thrombus formed in the pump impeller and quantified the thrombus hemoglobin concentration (Hb_thrombus). The spectrum changed around the center of the impeller, and the area of change expanded toward the impeller flow path. The shape corresponded approximately to the shape of the thrombus. The spectrum change indicated that the light scattering derived from red blood cells decreased. The Hb_thrombus was 4.7 ± 1.3 g/dL versus a total hemoglobin of 13 ± 0.87 g/dL. The study revealed that Hb_thrombus was reduced by the surrounding blood flow.     

Venous thromboembolic disease presenting as inferior vena cava thrombus extending into the right atrium

With increasing use of echocardiography, especially transesophageal echocardiography, the diagnosis of intracardiac masses has surged. Masses that are most commonly seen in the atrial chambers include thrombi due to atrial fibrillation, cardiac myxomas often located in the atria, and valvular vegetations of infective endocarditis. In this report we present a case of a patient who developed thrombus in the inferior vena cava that extended up to the right atrium and presented as an apparent intracardiac mass. This mass embolized to the right pulmonary artery shortly after diagnosis resulting in pulmonary embolism, which the patient fortunately survived.     

血栓性状与急性肺栓塞相关性的动物实验研究

目的：将兔静脉血在体外自然凝固制成栓子，观察不同时间组血栓性状与肺栓塞的相关性。方法：将24只家兔随机分成两组，分别注入体外凝固20分钟栓子与60分钟栓子。将栓子导管导入右心房，建立肺栓塞的动物模型。造影观察PE；大体观察PE后栓子形态；光镜观察肺小动脉内血栓；电镜观察不同时间组血栓的性状。结果：（1）20分钟组未发生PE；60分钟组除2例死亡均发生PE并模拟出PE的临床肺心病型和猝死型。（2）电镜显示20分钟组血栓的纤维蛋白体积大、呈束状，纤维蛋白丝密集排列、结构清晰；60分钟组血栓的纤维蛋白体积小、呈短杆状，纤维蛋白丝疏松排列、部分区域结构不清。结论：（1）导管在右心房注入自身血液凝块可制出有效的PE模型。（2）注入血块的数量及速度的不同，可分别模拟出PE临床急性肺心病型和猝死型。（3）不同时间的血液凝块作为栓子对肺血管血流量影响不同，表明血栓的性状与PE的发生有关。     

术前及术中超声造影对下腔静脉癌栓是否合并血栓的诊断价值

目的探讨术前及术中超声造影对下腔静脉癌栓是否合并血栓的诊断价值。 方法选取2017年10月至2019年3月解放军总医院收治的发现肾肿瘤伴下腔静脉癌栓并行腹腔镜手术治疗的患者60例，所有患者均于术前及术中行超声造影检查，以典型增强模式判断癌栓是否合并血栓，并最终取得术后病理结果。以术后病理结果为"金标准"，计算术前及术中超声造影评估癌栓合并血栓的敏感度、特异度、准确性、阳性预测值和阴性预测值。 结果60例下腔静脉癌栓患者均接受了机器人辅助腹腔镜下根治性肾切除联合下腔静脉内癌栓切除术。根据病理结果，下腔静脉癌栓合并血栓者10例（16.7%），其中术前超声造影漏诊2例，另有2例癌栓头部坏死组织被术前及术中超声造影误诊为血栓。术前与术中超声造影评估癌栓合并血栓的敏感度、特异度、准确性、阳性预测值、阴性预测值分别为80.0%、96.0%、93.3%、80.0%、96.0%和100.0%、96.0%、96.7%、83.3%、100.0%。 结论术前及术中超声造影对下腔静脉癌栓是否合并血栓有较好的鉴别诊断效能，可为手术方式的选择提供重要信息和依据，具有较高的临床应用价值。     

局部动态法核素显像诊断下肢深静脉血栓的临床研究

目的：探讨局部动态法放射性核素显像（rdRNV)诊断下肢深静脉血栓的价值。方法：利用SPECT对297例可疑下肢深静脉血栓患者进行^99mTc-MAA rdRNV检查。检查：rdRNV诊断中央型下肢深静脉血栓及周围型下肢深静脉血栓的灵敏度分别为97．1％、87．5％，特异性分别为95．0％、89．3％。结论：rdRNV简便、无创、短期内可重复进行，是一种可靠的诊断下肢深静脉血栓方法。