Intracardiac Mass Detection and Classification Using Double Convolutional Neural Network Classifier

Intracardiac masses identification in the images of echocardiogram images in one of the most essential tasks in making the diagnosis of cardiac disease. For making the improvement in accuracy over the diagnosis as a new complete method of classifying the echocardiogram images automatically which is based on robust back propagation neural network algorithm in being proposed for distinguishing intracardiac thrombi and tumor. Initially, the cropping over the specific region is done in order to make the definition of the mass area. Later on, as the second step the processing of globally unique denoising technique is being implied for the removal of speckle and in order to make the preservation of anatomical structured component in the image. This is defined in terms of preprocessing and it is carried out by Patch-based sparse representation. Subsequently the description of the mass contour and its interconnected wall of the artery are being done by the segmentation mechanism denoted as Linear Iterative Vessel Segmentation model. As the prefinal stage, the processing of boundary, texture and the motion features are being carried out through the processing by double convolutional neural network (DCNN) classifier in order to determine the classification of two different masses. Totally 108 cardiac masses images are being collected for accessing the effectiveness of the classifier. It is also realized with the various state of the art classifiers as projected the demonstration of the greatest performance that has been disclosed with an achievement of 98.98% of accuracy, 98.89% of sensitivity and 99.16% of specificity that has been resulted for DCNN classifier. It determines the explication that the proposed method is capable of performing the classification of intracardiac thrombi and tumors in the echocardiography and ensures for potentially assisting the medical doctors who are in the clinical practice.

Abstract 17083: Hunting For Clot: Strokes In Patients With Cardiac Amyloid

Case Presentation: A 76-year-old female with history of amyloid light chain (AL) cardiac amyloidosis and prior stroke presented with acute bilateral leg weakness. MRI of the brain revealed subacute infarcts in the right basal ganglia and precentral gyrus as well as chronic left cerebellar infarctions. CT angiogram of the head and neck did not show any significant intracranial or carotid artery disease. All current and previous admission ECGs and telemetry showed sinus rhythm with no atrial arrhythmias. Transthoracic echocardiogram with bubble study noted LV ejection fraction of 62%, normal left atrial size and no evidence of an intracardiac shunt. Despite the lack of traditional indicators, a cardioembolic source was feared given the high risk of intracardiac thrombi in AL amyloid patients. A TEE was performed and confirmed a large left atrial appendage (LAA) thrombus with severely reduced velocities and spontaneous echo contrast (Figure 1). The patient was started on apixaban for secondary stroke prevention. Discussion: Amyloid proteins deposit throughout heart tissue, distorting mechanical function and electric conduction resulting in reduced blood flow and a high risk of intracardiac thrombi that is 10 times that of nonamyloid patients. Patients with cardiac amyloidosis have a high prevalence of atrial arrhythmias, particularly atrial fibrillation, but remain at significant risk of thrombi even in the absence of these arrhythmias, ranging from 3-20%. Risk factors for clot include AL type amyloid and features of worsened hemodynamics such as LV systolic and diastolic dysfunction, elevated heart rates and lower systolic blood pressure. This case demonstrates the importance of aggressively “hunting” for intracardiac thrombi in amyloid patients presenting with stroke even without perceived risk factors, especially given the protective effect of starting anticoagulation.

Transesophageal Echocardiography in Ischemic Stroke With Atrial Fibrillation

Background To clarify differences in clinical significance of intracardiac thrombi in nonvalvular atrial fibrillation‐associated stroke as identified by transesophageal echocardiography (TEE) and transthoracic echocardiography (TTE). Methods and Results Using patient data on nonvalvular atrial fibrillation‐associated ischemic stroke between 2011 and 2014 from 15 South Korean stroke centers (n=4841) and 18 Japanese centers (n=1192), implementation rates of TEE/TTE, and detection rates of intracardiac thrombi at each center were correlated. The primary outcome was recurrent ischemic stroke at 1 year after the onset. A total of 5648 patients (median age, 75 years; 2650 women) were analyzed. Intracardiac thrombi were detected in 75 patients (1.3%) overall. Thrombi were detected in 7.8% of patients with TEE (either TEE alone or TEE+TTE: n=679) and in 0.6% of those with TTE alone (n=3572). Thrombus detection rates varied between 0% and 14.3% among centers. As TEE implementation rates at each center increased from 0% to 56.7%, thrombus detection rates increased linearly (detection rate [%]=0.11×TEE rate [%]+1.09 [linear regression], P <0.01). TTE implementation rates (32.3%–100%) were not associated with thrombus detection rates ( P =0.53). Intracardiac thrombi were associated with risk of recurrent ischemic stroke overall (adjusted hazard ratio [aHR] 2.35, 95% CI, 1.07–5.16). Thrombus‐associated ischemic stroke risk was high in patients with TEE (aHR, 3.13; 95% CI, 1.17–8.35), but not in those with TTE alone (aHR, 0.89; 95% CI, 0.12–6.51). Conclusions Our data suggest clinical relevance of TEE for accurate detection and risk stratification of intracardiac thrombi in nonvalvular atrial fibrillation‐associated stroke. Registration URL: https://www.clinicaltrials.gov ; Unique identifier: NCT01581502.

Dual therapy with clopidogrel and rivaroxaban in cats with thromboembolic disease

Objectives Feline arterial thromboembolism (ATE), an often devastating outcome, was recently shown to affect 11.3% of cats with hypertrophic cardiomyopathy over 10 years. Current American College of Veterinary Internal Medicine guidelines recommend the use of clopidogrel in cats at risk for ATE, with addition of a factor Xa inhibitor in very high risk or post-ATE cases. To date, no studies have examined the safety or efficacy of this combined antithrombotic therapy. This retrospective case series aimed to assess the frequency and type of adverse events that occurred in cats prescribed dual clopidogrel and rivaroxaban therapy. Secondary aims were to evaluate indications for dual therapy and clinical outcome. Methods The study included 32 cats prescribed clopidogrel (18.75 mg PO q24h) and rivaroxaban (2.5 mg PO q24h) on an outpatient basis over a 5-year period. Results Cats were prescribed dual therapy for at least one of the following: ATE event (n = 18), presence of an intracardiac thrombi (n = 17) or presence of spontaneous echocardiographic contrast (SEC) (n = 16). Five cats experienced adverse effects that could be attributed to medications, a median of 13 days from initiation (epistaxis, hematemesis, hematochezia or hematuria). No cat required hospitalization as a result of these events. Median survival time from onset of therapy was 257 days (interquartile range [IQR] = 38–497) for all cats, 502 days (IQR = 171–663) for ATE cats, 725 days (IQR = 133–856) for cats with an ATE to two or more limbs and 301 days (IQR = 221–431) for cats with only one limb affected. Recurrence rate of ATE while on dual therapy was 16.7%; no cat newly developed an ATE while on dual therapy. Conclusions and relevance Dual antithrombotic therapy with clopidogrel and rivaroxaban resulted in a low reported incidence of adverse events. Cats placed on dual therapy for an ATE event experienced a low rate of recurrence and effective thromboprophylaxis was achieved in cats with intracardiac thrombi or SEC.

Prone-position computed tomography in the late phase for detecting intracardiac thrombi in the left atrial appendage before catheter ablation for atrial fibrillation

Background: Contrast computed tomography (CT) is a useful tool for the detection of intracardiac thrombi. We aimed to assess the accuracy of the late-phase prone-position contrast CT (late-pCT) for thrombus detection in patients with persistent or long-standing persistent atrial fibrillation (AF). Methods: Early and late-phase pCT were performed in 300 patients with persistent or long-standing AF. If late-pCT did not show an intracardiac contrast defect (CD), catheter ablation (CA) was performed. Immediately prior to CA, intracardiac echocardiography (ICE) from the left atrium was performed to confirm thrombus absence and the estimation of the blood velocity of the left atrial appendage (LAA). For patients with CDs on late-pCT, CA performance was delayed, and late-pCT was performed again after several months following oral anticoagulant alterations or dosage increases. Results: Of the 40 patients who exhibited CDs in the early phase of pCT, six showed persistent CDs on late-pCT. In the remaining 294 patients without CDs on late-pCT, the absence of a thrombus was confirmed by ICE during CA. In all six patients with CD-positivity on late-pCT, the CDs vanished under the same CT conditions after subsequent anticoagulation therapy, and CA was successfully performed. Furthermore, the presence of residual contrast medium in the LAA on late-pCT suggested a decreased blood velocity in the LAA (≤ 15 cm/s) (sensitivity = 0.900 and specificity = 0.621). Conclusions: Late-pCT is a valuable tool for the assessment of intracardiac thrombi and LAA dysfunction in patients with persistent or long-standing persistent AF before CA.

Multiple Intracardiac Masses as the Primary Presentation of a Systemic Inflammatory Disease: A Big Challenge (Case Report)

Antiphospholipid syndrome (APS) classically presents with venous or arterial thrombosis and pregnancy morbidity. Although clinical manifestations with fever of unknown origin and intracardiac masses are unusual, in a patient with prolonged fever and multiple intracardiac thrombi, systemic inflammatory diseases such as APS should be considered.