BackgroundCardiac amyloidosis (CA) has been associated with a high prevalence of intracardiac thrombi, but this was reported in small cohorts of high risk patients (with a clinical indication for ...transoesophageal echocardiography). It is therefore not known whether such observations are applicable to the general CA population.PurposeTo assess the prevalence of intracardiac thrombi in patients with CA.Methods324 consecutive patients with CA were studied prospectively using a standard CMR protocol at 1.5T, including early and late gadolinium imaging and T1 mapping. Early gadolinium images (segmented imaging, trigger 2) of the left atrial appendage (LAA) were acquired using a 5 mm contiguous stack and a TI of 440 ms.ResultsThe study participants comprised 155 with light chain CA (AL), 166 with transthyretin amyloidosis (ATTR), 2 with Apo A-I, and 1 with Apo A-IV CA. The prevalence of intracardiac thrombi was 5.2% in AL, 7.2% in ATTR; 6.2% overall. 90% of thrombi were in the LAA. This was higher when there was atrial fibrillation (9.1% AL, 14.3% ATTR) but intracardiac thrombi were also present in sinus rhythm (SR) 3.1% (4.5% AL, 1.1% ATTR). In all patients with AF the thrombi were present despite long term anticoagulation. The presence of intracardiac thrombi was associated with a greater degree of systolic dysfunction and myocardial amyloid infiltration (higher native T1 and ECV).Abstract 21 Figure 1Acquisition of stack through the LAA. Early gadolinium ¡mages of the LAA (bottom row) acquired using a 5 mm contiguous stack through the LAA (top row) and an inversion time of 440 ms to confirm the presence or absence of thrombus vs normal pectinate muscle. The thrombus in the left atrial appendage can only be visualised in the last two images (red arrows in panel 4 and 5) and could have been missed with the acquisition of only one imageConclusionsThe prevalence of intracardiac thrombi in CA and AF is high despite long term anticoagulation, with significant thrombus prevalence even in SR, meriting vigilance for intracardiac thrombi in all. CMR with early gadolinium imaging of the LAA is a valuable screening tool for thrombi in the LAA and should be routine part of the clinical protocol when amyloidosis is suspected. Current guidelines for electrical cardioversion after prolonged anticoagulation without screening forthrombus in the LAA should not be applied to patients with CA.
IntroductionThe susceptibility vessel sign (SVS) is a radiological sign on the SWI sequence of MRI that can predict cardioembolic source and increased recanalisation rates in stroke.1 We present a ...case of an 86 year old female with resolving neurological deficits from a propagating left MCA thrombus with positive SVS on imaging.CaseAn 86 year old female presented with sudden onset right sided weakness and expressive aphasia in the context of new atrial fibrillation. Her NIHSS was 4. Initial CT angiogram showed complete occlusion of the proximal M1 segment of the left middle cerebral artery. She was within the thrombolysis window but her deficits largely resolved (NHISS 0) before thrombolysis could be administered. A repeat CT angiogram one hour after the first scan showed complete resolution of the MCA occlusion. An MRI brain showed curvilinear gradient signal hypointensity in the distal left M2 segment of the MCA (positive SVS) with a small area of infarction and restricted diffusion. She was discharged on apixaban without neurological deficit. This is a unique case of a stroke patient, with proximal large vessel occlusion, presenting with neurological deficits that self-resolved within minutes without thrombolysis or thrombectomy. There was a positive SVS on MRI. This radiological sign allows direct visualisation of the hypointense thrombo-embolus on the SWI sequence. It occurs as there is a higher level of deoxy-haemoglobin content in the thrombo-embolus and is predictive of a cardioembolic source as cardioembolic thrombi are rich in erythrocytes1.ConclusionOur case demonstrated interesting clinical-radiological-pathological correlation in cardioembolic stroke with resolving neurological deficits. The patient’s clinical improvement matched the radiological improvement and corresponded to the pathophysiological course of thrombus from embolization, propagation, occlusion, dissolution and then recanalisation. The SVS is a useful radiological sign to predict cardioembolic sources of stroke and is associated with higher vessel re-canalisation rates.Reference. Cho KH, Kim JS, Kwon SU, et al. Significance of susceptibility vessel sign on T2*-weighted gradient echo imaging for identification of stroke subtypes. Stroke2005;36:2379–2383.
Introduction Mechanical thrombectomy has been widely recognized as the preferred treatment for large vessel occlusion strokes. The Tigertriever stent‐retriever (Rapid Medical, Yokneam, Israel) is a ...novel operator‐adjustable device that can be actively expanded and contracted by the operator 1, which allows for several actuation‐related parameters to be optimized to potentially improve device efficacy. These parameters – such as amplitude and frequency of the actuation cycle, and rate of expansion and contraction – have not yet been evaluated in correlation with device success. We conducted a benchtop study to evaluate the effect of actuation frequency on clot integration within the stent. Methods A Tigertriever 17 device was deployed within a biological thrombus analog (2.5 cm length) placed in a straight silicone tube (2.4 mm diameter). The device was actuated between the maximally contracted and maximally expanded states with three different frequencies: Passive (one‐time opening, n=6), Slow (20 seconds/cycle, n=6), and Fast (5 seconds/cycle, n=7). A flat‐detector CT scan was acquired, the clot and stent wires were segmented, and the boundaries of the clot and stent wires were calculated on each axial slice (Figure 1A). The intersection between the stent and clot boundaries throughout the volume was defined as the volume of clot integrated within the stent. The clot integration factor (CIF, ratio of integrated clot volume to total clot volume) was then statistically compared between the three frequencies as an estimate of clot capture efficiency. Results The CIF was significantly higher (23% increase, p=0.01) with the Fast actuation as compared to the Passive and Slow actuations, with a post‐hoc test showing no difference (p>0.05) between the Passive and Slow actuation frequency (Figure 1B). Conclusion The unique malleability of the Tigertriever stent‐retriever (Rapid Medical) presents an opportunity to better understand actuation parameters that can maximize thrombus capture. Results indicate that faster actuation frequencies may result in improved clot integration with the Tigertriever device. These results are concordant with a previous clinical study 1 that found repetitive‐expansion‐contraction was more successful than single unsheathing (which corresponds to our Passive group). It is possible that the greater acceleration of the stent mesh wires in the Fast actuation frequency resulted in increased radial forces that improved clot integration. This effect must be further validated in an in vitro setting more representative of physiological conditions, as well as eventual clinical evaluation.
BackgroundThe age-thrombus score-index of microcirculatory resistance (ATI) score is a diagnostic tool recently applied by our group in ST elevation myocardial infarction (STEMI). It is able to ...predict suboptimal myocardial reperfusion early in the revascularisation process thus facilitating the triage of alternative or additional therapies to the conventional approach with stenting. We aimed to validate the ATI score against cardiac magnetic resonance imaging (cMRI).MethodsThe ATI score was calculated using age (>50=1 point), pre-stenting index of microcirculatory resistance (IMR) (>40 and <100=1 point; ≥100=2 points) and angiographic thrombus score (4=1 point; 5=3 points). cMRI scan was performed within 48 hours from admission and at 6 months follow up to assess the extent of infarct size (IS%) and microvascular obstruction (MVO%).ResultsThe ATI score was calculated prospectively in 80 STEMI patients. cMRI scanning was performed within 48 hours in all patients and in 50 patients at six months follow up. ATI score was closely related to final IS% (ATI0-1: 18.0% 9.0–24.5, ATI2-3: 28.5% 12.8–43.0 and ATI4-5-6: 41.2% 22.0–44.4 p: 0.001) and with MVO% (ATI0-1: 0.0% 0.0–0.9, ATI2-3: 0.7% 0.0–2.5 and ATI4-5-6: 4.1% 1.2–10.7, p<0.001). ATI score predicted final IS% at six months follow up (ATI0-1: 12.7% 4.5–22.0, ATI2-3-: 20.0% 6.4–25.6 and ATI4-5-6: 34.0% 22.2–46.5, p: 0.02).ConclusionsThe ATI score applied prior to stenting in patents with STEMI, can predict the likelihood of MVO% and IS% both acutely and at six months follow up cMRI.
IntroductionEXCELLENT (NCT03685578) is a prospective, single-arm, multicenter, real-world international registry of mechanical thrombectomy (MT) for stroke with the EmboTrap device as first line ...treatment. The study entails thrombus analysis of specimens collected with each MT pass.Aim of the StudyTo compare rates of mRS 0–2 at 90 days and clot characteristics in subjects with and without first pass effect (FPE).MethodsFPE was defined as mTICI 2c/3 after one pass and non-FPE as mTICI 2c/3 after >1 pass as adjudicated by an independent core lab. Clot analysis was performed by independent central labs blinded to clinical data. mRS at 90 days was scored by investigators blinded to procedural data.ResultsOverall mTICI2c/3 rates were 63.7% (326/512). FPE was achieved in 37.1% (190/512) and non-FPE in 26.6% (136/512) subjects. 90 day mRS 0–2 or equal to pre-stroke was achieved in 47.2% (75/159) with FPE and in 42.1% (51/121) non-FPE patients. All-cause 90-day mortality was 19.1% (34/178) in subjects with FPE and 26.4% (34/129) in subjects with non-FPE. Major thrombus components (mean% ±SD) were as follows: RBC: FPE 45.88±20.54, non-FPE 39.08±18.23, and first pass mTICI<2c/3 40.96±18.84; Fibrin: FPE 24.72±13.82 , non-FPE 29.09±15.76 first pass mTICI<2c/3 29.20±14.58.ConclusionsThe high rate of ‘real-world’ FPE observed in EXCELLENT was associated with improved clinical outcomes. Clots retrieved with FPE had higher RBC and lower fibrin content compared to non FPE and to first pass mTICI <2c/3 e. These preliminary findings await confirmation from analysis of the full dataset.DisclosureEXCELLENT is sponsored by Cerenovus. Dr. Jovin is a consultant for Neuravi, Codman Neurovascular, Stryker (PI DAWN; unpaid), Fundacio Ictus (PI REVASCAT; unpaid), and holds stock in Anaconda, Silk Road, and Blockade Medical.
BackgroundTransoesophageal echocardiography is recognized as the gold standard for detection of a left atrial appendage (LAA) thrombus. LAA thrombus is visualized as filling defect on computed ...tomography (CT), however it can be difficult to differentiate between slow flow and thrombus. This poses challenges in both the reporting and interpretation of left atrial filling defects on non-cardiac gated CTs, and whether to classify this as thrombus or an issue with imaging technique when reporting. Due to the risk of stroke with a LAA thrombus, the reporting of a LAA thrombus on CT makes it difficult for physicians to ignore and usually leads to anti-coagulation, thereby exposing the patient to the risk of bleeding. In this study we assessed the correlation between left atrial appendage thrombus or filling defects on a non-cardiac gated CT, with confirmation on TOE.MethodsWe retrospectively analyzed TOE cases performed at our center between March 2016 and March 2020. Patients were included if they had been referred for LAA assessment following identification of a suspected LAA thrombus on CT thorax.Results757 TOEs were conducted at our center during the study period. This study includes 19 patients who were referred for TOE following incidental left atrial appendage thrombus on CT. Baseline characteristics include; mean age 69.5 years, male 68.4%, hypertensive 79%, history of atrial fibrillation 63.2%, on long-term anticoagulation 63.2%, on anti-coagulation following CT prior to TOE 89.5%, previous stroke 21%, median CHA2DS2-VASC 3. The mean time from CT to TOE was 16 days.15.8% (n = 3/19) of the patients referred had evidence of a LAA thrombus on TOE. 66% (n = 2) of these patients had a history of prior stroke, the median CHA2DS2-VASC score was 5 and overall 50% of the patients in our cohort who had a history of stroke had a LAA thrombus at TOE. The mean peak LAA filling velocity was only mildly reduced at 37 cm/s, and 63% (n = 12) of LAA were windsock morphology. In the follow-up period from TOE to data collection, there was no reported subsequent strokes in the 19 patients analyzed, mean follow-up time 14 months.DiscussionIn patients who have an incidental left atrial thrombus or filling defect reported on non-gated CT thorax, only a minority have a thrombus at TOE and it was no associated with subsequent stroke risk. A history of stroke or CHA2DS2-VASC of >5 conferred a higher probability of thrombus being present and we recommend that physicians take this into consideration when deciding on anti-coagulation. The LAA filling velocities were only mildly reduced and the radiographic findings are likely related to CT gating rather than an physiological process in the left atrium. Incidental LAA thrombus on CT correlates poorly with presence of thrombus on TOE, and if there is concern a TOE should be performed to assess for a thrombus.
IntroductionMechanical thrombectomy is an established treatment for large vessel occlusion (LVO) in stroke. However, Intracranial Atherosclerotic Disease (ICAD) presenting as LVO can complicate ...mechanical thrombectomy and increase risks.Aim of StudyThe aim of this study was to evaluate pre-thrombectomy imaging for ICAD and assess the predictive value of the hyperdense artery sign on CT head and the tapering sign on CT angiography, respectively.MethodsA retrospective radiological review of ICAD cases was conducted using data from the institutional thrombectomy database. Patients who underwent thrombectomy for large vessel occlusion were selected, and a control group without ICAD was matched to the ICAD group based on age and thrombus location.ResultsThe study included 26 patients, with 13 diagnosed with ICAD. The mean age of the patients was 56.6±16.1 years. The ICAD group had a lower prevalence of hyperdense thrombus compared to the non-ICAD group (30.8% vs. 84.6%; p<0.01), resulting in a sensitivity of 30.8% and a specificity of 15.4% for detecting ICAD. Tapering at the occlusion site on CT angiography was observed more frequently in the ICAD group (53.8% vs. 7.7%; p=0.01), resulting in a sensitivity of 53.9% and a specificity of 92.3% for detecting ICAD. The results demonstrated perfect agreement between the two readers.ConclusionOur findings suggest a significant association between the absence of the hyperdense artery sign and the presence of tapering at the occlusion site with ICAD in patients with LVO. Incorporating these signs in pre-thrombectomy evaluation has the potential to improve stroke care.Disclosure of InterestDr. Joe Leyon has/had consultancy agreements with Microvention Terumo, Medtronic, and Stryker Neurovascular.
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