Left atrial thrombus exclusion before atrial fibrillation ablation: Reconsidering the role of cardiac computed tomography

Objectives: Considering the risk of aerosolization during the COVID-19 pandemic associated with transesophageal echocardiography (TEE), we evaluated the diagnostic performance of cardiac computed tomography (CCT) before pulmonary vein isolation (PVI) in comparison to semi-invasive TEE in excluding left atrial (LA)/LA appendage (LAA) thrombus, limiting the need for TEE to only patients with possible thrombus on CCT. Material(s) and Method(s): We included a total of 145 consecutive patients with atrial fibrillation (AF) (age 52.4 +/- 10.3 years;63% males;89 paroxysmal AF) referred for radiofrequency ablation in National Cardiovascular Center Harapan Kita, Jakarta, Indonesia. All patients underwent preprocedural single-phase 128-slice multidetector CT and subsequent TEE as the reference standard with a mean time interval of 6.5 +/- 5.3 days between the two procedures. Result(s): CCT identified 30 patients (20.7%) with a filling defect in the LA/LAA, 8 of which were confirmed by TEE as thrombi (22 false positives and 8 true positives), whereas 9 true thrombi (6.2%) were detected by TEE (1 false negative by CCT). The sensitivity and specificity of CCT were 88.9% and 83.8%, respectively, with a positive predictive value of 26.8% and a negative predictive value of 99.1%. The overall accuracy was 84.1%. Conclusion(s): Apart from being a planned preparation modality before PVI, CCT is sufficient and could be used as an initial step to exclude the presence of LA/LAA thrombus, limiting the invasive TEE only for confirmation of the thrombus if detected by CCT.

Imaging Cascade - the Importance of Pre-Procedural 3-D Planning in Transcatheter Left Atrial Appendage Closure

Background With the COVID-19 pandemic and referral from out-reach centers, there has been a change in practice of assessing left atrial appendage (LAA) via TEE on the day of LAA closure (LAAC). We present a challenging case of inadequate LAAC with WATCHMAN FLX due to suboptimal TEE images. Follow up TEE and CT revealed a much larger LAA ostium that was mostly uncovered. Case An 84 yo male with AF and recent hepatic hematoma, was referred for LAAC. LAA dimensions were measured using a technically difficult intraprocedural (IP) 2D TEE and a 24mm Watchman FLX was successfully implanted. Follow up 3D TEE at 45 days revealed incomplete LAAC with a large PDL. Retrospective review of fluoroscopic images revealed unrecognized filling of a posterior LAA lobe. Decision-making Anticoagulation (AC) was continued for 3 more months, and Cardiac CT was performed which showed persistent under-coverage of the LAA with large PDL of 16.5 x 11.3 mm (159mm2). A much larger ostium was measured on 45 days TEE (27 mm max 2 D dimension) and 145 days CT (18 X 25 mm) vs. 12.9 mm on IP-TEE. AC was continued with consideration of a 2nd adjacent device placement in future. Conclusion TEE on the day of LAAC although implemented in several centers, has its limitations. In the presence of sub-optimal image quality, it can lead to incorrect device sizing and incomplete LAAC as in our case. Cardiac CT with 3D evaluation or 3D TEE are crucial for pre-planning to achieve successful device implantation. [Formula presented]Copyright © 2023 American College of Cardiology Foundation

Left Atrial Septal Pouch Thrombosis after Covid19 Infection: Is Immunothrombosis the Culprit Mechanism?

Aims: The atrial septal pouch (ASP) is an incomplete fusion between septum primum (SP) and septum secundum (SS), resulting in a kangaroo pouch, that has a high prevalence in general populations (47%) and it is a potential site of blood stasis and thrombosis. After the novel coronavirus disease (COVID19) -related thrombotic complications, immunothrombosis has been widely investigated and proposed as key pathogenic mechanism linking coagulation and inflammation, leading sometimes to intracardiac thrombosis. In this paper we describe a case of thrombus in the ASP interestingly developed after COVID19 and made a literature review. Methods and Results: A 85 years old woman with a history of hypertension and chronic atrial fibrillation (AF) in therapy with dabigatran, was admitted to our hospital for dyspnea, atypical chest pain and fever. Laboratory exams showed only mild leukocytosis and elevated levels of d-dimer;EKG confirmed AF with a normal ventricular rate and CT scan excluded pulmonary embolism. Transthoracic and transesophageal echocardiogram (TEE) (Figure 1) showed a mobile ovoid mass (13x26 mm) attached to a left-sided ASP mimicking a myxoma, no mass was seen in the left atrial appendage (LAA). Four months earlier she had been hospitalized for idiopathic thrombocytopenia and concurrent COVID19 infection with mild symptoms, therefore dabigatran was discontinued for a month. The patient underwent surgery and histopathology confirmed it was a thrombus. In the PubMed search we conducted for reports demonstrating ASP masses, or alleged thromboembolism (TE) from this site, we found 25 reports, whose characteristics are briefly summarized in Table 1. Interestingly mild thrombocytopenia was described just in one case. Conclusion(s): In addition to the LAA, the atrial septal pouch is a newly described, common anatomic entity of the interatrial septum, that potentially serves as a site of stasis and thrombus formation. Despite its high prevalence, the finding of a thrombus in this site is very rare. According to Virchow triad, we assume that in this case an endothelial injury and hypercoagulability could have played a pivotal role, since the concomitant thrombocytopenia and high levels of d-dimer. This could be the first case of a thrombus in the ASP associated with COVID19-immunothrombosis. (Table Presented).

Cardiac Computed Tomography to Exclude Left Atrial Appendage Thrombus in Atrial Arrhythmias Prior to Direct Current Cardioversion During COVID-19 Pandemic

Background: Transoesophegeal echocardiogram (TOE) is the gold standard imaging modality to evaluate the left atrial appendage (LAA) prior to direct current cardioversion (DCCV) for atrial arrhythmia. TOE is an aerosol generating procedure, with the potential for transmission of COVID-19 infection. This study describes our experience of utilising cardiac computed tomography (CT) as an alternative imaging modality, to exclude LAA thrombus prior to DCCV in patients with atrial arrhythmias at Middlemore Hospital from 1st September 2020 until 30th September 2021 during the COVID-19 pandemic. Method: Patients with atrial arrhythmia requiring DCCV who underwent cardiac CT were identified from ANZACS-QI linked cardiac CT registry database. Patients without thrombus on cardiac CT proceeded to DCCV. Patients with slow flow or thrombus in the left atrium (LA) or LAA on CT were considered for TOE. Results: Eighty-five cardiac CT scans were performed in eighty patients (male 68.8%, mean age 59.3±14 years, body mass index 33.4±8). Sixty-seven patients (87%) had no LAA thrombus, and 65 patients proceeded safely to DCCV with no periprocedural stroke. Thirteen patients (16%) had slow flow or possible thrombus in the LA or LAA and one patient had definite thrombus. Six patients with slow flow or possible thrombus underwent TOE none had LA or LAA thrombus. Conclusion: In the majority of patients with atrial arrhythmia requiring DCCV, cardiac CT is a safe and useful alternative to TOE.

Accidental diagnosis of significant coronary artery disease by cardiac CT scan to rule out left atrial appendage thrombus in patients with atrial fibrillation during COVID19 pandemic

Introduction The exclusion of left atrial appendage (LAA) thrombus prior to urgent electrical cardioversion (DCCV) for atrial fibrillation (AF) is traditionally performed by transesophageal echocardiography (TEE). During the COVID19 pandemic, TEE was replaced by cardiac CT (CCT) due to its high aerosol generating property, which in addition to assessing the anatomy of the heart, can also be used to evaluate the coronary arteries at the same time. Methods In our retrospective study, we evaluated the cardiac CT scans of patients undergoing DCCV in our institution between January 1, 2020 and February 28, 2021 for coronary artery disease (CAD). The scans were performed by a GE Revolution 256-slice CT scanner. Results CCT scans were performed in 32 patients to rule out LAA thrombus (24 male;8 female;age: 61.8 ± 11.2 years;BMI: 29.2 ± 4.4;heart rate: 79.2 ± 24.4 1/min;CHA2DS2VASc score: 2.4 ± 1.5). The mean radiation exposure of the scans was DLP: 356.3 ± 130.1 mGy-cm;effective dose: 5.0 ±1.8 mSv, Ca-score: 361.4 ± 883.0. In 4 equivocal cases TEE was also performed with negative results. No CAD was confirmed in 7 cases, mild CAD in 14 patients. CCT was not diagnostic only in 4 cases. Significant (moderate or severe) CAD was detected in 7 cases, invasive coronary angiography (ICA) was also performed in 5 cases. In 2 cases significant one-vessel disease, in 2 other cases borderline (FFR: 0.81 and 0.84) stenosis and in 1 case only mild CAD was diagnosed by ICA. Conclusions: CCT scans performed by our 256-slice CT scanner for AF can identify patients, who require further invasive or invasive and functional coronary artery assessment with satisfactory accuracy. In terms of coronary artery disease, the non-diagnostic scan rate was low, despite the presence of arrhythmia, suboptimal heart rate and higher than usual Ca-score.

SAFETY AND CRITERIA FOR PERCUTANEOUS LEFT ATRIAL APPENDAGE OCCLUSION SAME DAY DISCHARGE

Background: Left Atrial Appendage Occlusion (LAAO) with the Watchman device is considered an elective procedure, and thus often deferred during outbreak peaks associated with the COVID-19 pandemic. Patients with bleeding issues on anticoagulation may require additional hospitalization for bleeding episodes or suffering increased risk of stroke by postponing occlusion while anticoagulation is discontinued. We chose to develop a protocol for screening, same day discharge, and follow up of selected LAAO patients and continuing to provide quality clinical outcomes while accounting for decreased bed and staff capacity due to the pandemic. Methods: Utilizing Knowledge to Action (KTA) nursing framework, a protocol was developed and reviewed with key stakeholders. Criteria for Same Day Discharge (SDD) includes: support at home, stable vitals and access site hemostasis prior to DC, agreeable to SDD, tolerant of oral intake, ability to urinate and safely ambulate prior to DC. Exclusion for SDD includes: Liver disease, Plt count <70,000, ESRD or CKD IV or any site or procedure complications. With Perclose usage patients must have 3 hours of bedrest, with manual pressure closure must have bedrest for 6 hours and purse string suture removed. This is followed by a next day phone call to ensure the patient is taking appropriate medicines and have no medical issues. Results: 38 out of 113 patients were screened as SDD candidates from January 2021-October 2021. Average patient age was 76, 31% female, with average CHA2DS2-VASc of 5. One patient required overnight hospitalization due to underlying asthma and need for nebulizer. One patient presented to an outpatient ED on a weekend with chest pain and underwent heart catheterization due to elevated troponin and did not require intervention. There were no access site complications. No patients contracted SARS-Cov-2 within 6 weeks post procedurally, compared with 2 of the overnight stays during the same period (75 patients). Conclusion: SDD in a carefully selected patient population is a feasible and safe strategy for LAAO patients. These patients had a clinically significant, though underpowered decrease in incidence of COVID-19 diagnosis within 6 weeks post implant.

Covid-19 pfizer-biontech vaccine induced vte

Case Report Between December 2019 and May 2021, there were around 200 million cases of COVID-19, with more than 3.5 million deaths all over the world. In the United States alone, there were more than thirty million cases, with around six hundred thousand deaths attributed to COVID-19. Incidents of hypercoagulability after receiving different types of COVID-19 vaccine have been reported. The incidence of deep vein thrombosis (DVT) is about 1 in 1000, and about 50% of these patients with DVT develop pulmonary embolism (PE). The incidence of DVT affecting the upper extremity exceedingly rare with an approximate incidence of 1 in 10,000. While patients receiving anticoagulation are still at risk of DVT, data on apixaban reflects a 98% protection from recurrent thrombosis. Hypercoagulability including DVT and PE is always a rising concern in patients with COVID-19 pneumonia. We are reporting a case of a hypercoagulability state in 73-year-old lady after receiving first and second dose of Pfizer vaccine;despite being on apixaban. she has a past medical history of COPD on 2 L home oxygen. She presented with acute hypoxic respiratory failure few days after receiving the first dose of COVID-19 Pfizer vaccine. Imaging revealed right interlobar pulmonary embolism and right superficial femoral vein thrombosis without any provoking factors. She improved clinically and was discharged on apixaban. Few months later she came in with right upper extremity DVT, 7 days after receiving a second dose of Pfizer vaccine. Transesophageal Echo revealed a round mass in the left atrial appendage, which was likely a thrombus, she was discharged on warfarin. Incidence venous thromboembolism is about 1 in 1000 individuals in the United States. Several factors can increase the hypercoagulable state. SARS-COV-2 is hypothesized to increase the risk of thromboembolism by infecting cell expressing surface receptors of ACE-2 by binding the SARCOV-2 spike protein and activating cell pyroproptosis which activates neighboring cells inflammatory response and then activate coagulation pathway. BioNTECH mRNA vaccine induces immune response by engulfing S protein mRNA into the cell to produce spike protein and induce antibody production against SARS-COV-2 spike protein. At this time, this is the Third reported Vaccine related VTE after reporting a Pfizer BioNTech vaccine induced DVT on January 2021 After ruling out other causes of VTE in this case as well as the time between receiving the vaccine and the onset of symptoms, vaccine-induced thrombosis is the most likely cause for our patient's thrombosis, including venous thrombosis, pulmonary embolism, and left atrial appendage thrombosis. The mechanism remains unknown but may possibly be due to enhanced immune response to the vaccine. In patients at increased risk of thrombosis, BioNTech mRNA vaccination may induce Intravascular Coagulation, venous thromboembolism, possibly due to enhanced immune response to spike protein production.

ESC Congress 2021

The proceedings contain 3127 papers. The topics discussed include: automated left ventricular dimension assessment using artificial intelligence;fully automated global longitudinal strain assessment using artificial intelligence developed and validated by a UK-wide echocardiography expert collaborative;pocket-size ultrasound devices may improve the prompt assessment of Covid-19 patients;left atrial appendage velocity as an instrument of predicting atrial fibrillation recurrence after successful catheter ablation a useful tool?;RV free wall longitudinal strain as an independent predictor of survival in wtATTR-CA patients;global longitudinal strain as a predictor of cardiovascular events and mortality in patients with ischemic heart disease and heart failure with preserved/mid-range ejection fraction;myocardial work and long-term prognosis in patients after ST-segment elevation acute myocardial infarction;left atrial appendage function by strain predicts subclinical atrial fibrillation in patients with cryptogenic stroke/TIA;a comprehensive model to estimate underlying atrial fibrillation in cryptogenic stroke: the decrypting score;and exploration of electrocardiographic and echocardiographic findings to screen transthyretin amyloid cardiomyopathy in patients with mild left ventricular hypertrophy.