Complete Resolution Of Thrombus Research Articles

HALF DOSE THROMBOLYSIS IN INTERMEDIATE – HIGH RISK PULMONARY EMBOLISM WITH TRICUSPID VALVE MOBILE MASS: A BAIL OUT STRATEGY

Abstract A 82–year–old previously healthy male was referred to the emergency department complaining sudden onset dyspnea and witnessed syncope complicated by head trauma. Recurrent dizziness occurred previously. No history or drug consumption noted. On admission: heart rate 90 beats/min, blood pressure 110/60 mmHg, respiratory rate 25 breaths/min, oxygen saturation 87% in room air, normal body temperature. No lower extremities tenderness or swelling reported. Consistent with peripheral blood oxygen saturation levels, arterial blood gas analysis showed hypoxemia and respiratory alkalosis. Laboratory exams were significant for thrombocytopenia (89.000 cells/L), elevated cardiac troponin T levels (222 ng/L) and natriuretic peptide (NT pro–BNP 3944 pg/mL). Head CT excluded acute cerebral hemorrhage. At the electrocardiogram, signs of RV strain were present (biphasic T–waves in V1–V3 leads, S1–Q3–T3). Transthoracic echocardiography (TTE) showed dilated RV with hypokinetic free wall, “D–shaped” LV, “60/60” sign and a mobile filiform mass crossing the tricuspid valve plan in the right atrium (fig. 1). The patient did not present structural valvular abnormalities or endocarditis–related risk factors. CT pulmonary angiography detected a “saddle” PE and extensive thrombosis in inferior vena cava. After unfractioned heparin (UFH) bolus, the patient was transferred to our intensive care unit and balancing risks and benefits the chosen treatment option consisted in half dose systemic thrombolysis (50 mg rtPA in 60’’; 10 mg as loading dose in 2’). Because of potential harmful effects in thrombocytopenia and recent head trauma, UFH was temporarily withheld and started again after 1 hour. The day after, a beside TTE showed complete tricuspid thrombus resolution, a significant decrease in RV/LV ratio and systolic pulmonary artery pressure (fig. 2). Apart from small hematomas, no bleedings were reported. The patient was shifted to the ward on the next day and following course was uneventful. On day 4 a direct oral anticoagulant (Dabigatran 110 mg) was started. Abdominal and inferior limb–deep–venous ultrasound were both negative for pathological reports. A total body CT was scheduled to exclude silent malignancies at discharge. Take home message: in intermediate–high risk PE, half dose systemic fibrinolysis strategy is controversial since its potential benefit is counterbalanced by concerns about major bleedings, but increasing data suggest its efficacy with low risk profile.

Comparing clinical outcomes of Vitamin K antagonists versus Non-Vitamin K antagonists in anticoagulant therapy for mesenteric venous thrombosis

Non-vitamin K antagonist oral anticoagulants have shown similar efficacy and lower bleeding rates than Vitamin K antagonists for venous thromboembolism. However, this has not been proven in mesenteric vein thrombosis. This study aimed to compare the clinical outcomes of vitamin K antagonists and non-vitamin K antagonist oral anticoagulants. Between Jan 2014 and July 2022, mesenteric vein thrombosis was diagnosed on computed tomography in 225 patients in a tertiary hospital. Among them, a total of 44 patients who underwent long-term anticoagulation therapy over 3 months were enrolled in this study. Patients were divided into two groups based on the anticoagulant used: vitamin K antagonists (Group 1, n = 21) and non-vitamin K antagonist oral anticoagulants (Group 2, n = 23). The efficacy outcomes were symptom recurrence and thrombus resolution on follow-up computed tomography, and the safety outcome was bleeding complications. The median age of the patients was 56 years (46-68) and 52% were men. The most common risk factors were unprovoked intra-abdominal infections (30%). The median duration of anticoagulation therapy was 13 months (20 months in Group 1 vs. 6 months in Group 2; p = 0.076). Of the 44 patients, 17 (39%) received the standard treatment. The median follow-up period was longer in Group 1 than in Group 2 (57 vs. 28 months, p = 0.048). No recurrence of mesenteric vein thrombosis related symptoms were observed in either group. The median duration of follow-up computed tomography was 31 months (42 months in Group 1 vs. 18 months in Group 2; p = 0.064). Computed tomography revealed complete thrombus resolution, partial resolution, and no changes in 71%, 19%, and 10%, respectively (p = 0.075). Regarding bleeding complications, varix bleeding and melena developed in 2 patients in Group 2, and anticoagulation treatment thereafter ceased. Despite the short follow-up duration in the non-vitamin K antagonist oral anticoagulants group, there was no clinically significant difference in the thrombus resolution rate or bleeding complications when compared with the vitamin K antagonists group. Although research on the long-term effects of non-vitamin K antagonist oral anticoagulants in patients is limited, non-vitamin K antagonist oral anticoagulants can be considered an alternative to conventional treatments.

Dabigatran for Treatment and Secondary Prevention of Venous Thromboembolism in Pediatric Congenital Heart Disease.

Congenital heart disease (CHD) is common in children and associated with greater risk of thrombotic complications. Management of these complications with standard-of-care treatment is suboptimal for these children. The effectiveness and safety of dabigatran were demonstrated in pivotal pediatric studies for the treatment of acute venous thromboembolism (VTE; NCT01895777) and secondary VTE prevention (NCT02197416). We report safety and efficacy outcomes from subgroup analyses of these studies for children with CHD (diagnosed according to local practice) and those without. In NCT01895777, 17/21 (81.0%) and 16/27 (59.3%) patients with CHD (including cyanotic) treated with dabigatran and standard of care, respectively, met the primary end point (complete thrombus resolution, freedom from recurrent VTE, and freedom from VTE-related death; odds ratio [OR], 0.34 [95% CI, 0.08-1.23]). In patients without CHD, 41.0% (n=64) versus 34.9% (n=22) achieved this end point with the respective treatments (OR, 0.77 [95% CI, 0.42-1.41]). Although numerical differences were observed, no heterogeneity in treatment effect of dabigatran on the composite primary end point was detected in patients with and without CHD (interaction P =0.2674). In NCT02197416, recurrent VTE at 12 months occurred in 0/17 patients with CHD versus 3/194 (1.5%) without. No patient with CHD experienced major or clinically relevant nonmajor bleeding events. Data on favorable anticoagulant alternatives for the unmet needs of children with CHD are emerging, and our exploratory results suggest that dabigatran could be an appropriate treatment choice, although challenging sample size limitations in pediatric studies require cautious interpretation of findings. URL: https://www.clinicaltrials.gov; Unique identifiers: NCT01895777, NCT02197416.

Diagnosis, Management and Outcomes in Children with Paget Schroetter Syndrome: A Retrospective Cohort Study

Introduction Venous thoracic outlet syndrome occurs secondary to the extrinsic compression and impingement of the subclavian vein as it passes through the thoracic outlet, eventually resulting in upper extremity effort thrombosis, or Paget-Schroetter syndrome (PSS). This rare condition typically affects the dominant arm of athletic young adults with a history of repeated overhead activities. At Boston Children's Hospital (BCH), a multidisciplinary team of hematologists, interventional radiologists, and vascular surgeons manage these patients according to a standardized protocol including anticoagulation, pharmaco-mechanical thrombolysis, venoplasty, and decompressive rib-resection surgery. Herein we report the clinical and radiological outcomes of a cohort of patients with PSS managed at BCH. Objective The principle objective of this retrospective cohort study was to review the diagnosis, pharmacological, interventional radiology and surgical management, complications, and long-term outcomes of sequential pediatric patients (≤21 years) treated for PSS at BCH over a 3.5-year period of time (January 1, 2020 to July 31, 2023). Methods This study was performed as a part of an ongoing quality improvement initiative and was deemed exempt by the Institutional Review Board. Eligible patients were defined as children (≤21 years) with PSS per criteria established by the Society for Vascular Surgery. Clinical and demographic data, including post-thrombotic syndrome (PTS) scores of eligible patients were abstracted from their medical records. PTS evaluation at BCH is typically performed 6-12 months after DVT diagnosis using both the modified Villalta and Manco-Johnson instruments. Major bleeding, and recurrent/progressive thromboses were defined per published guidelines by the International Society on Thrombosis and Haemostasis. Standard statistical methods were used - median (range) for continuous variables and frequency with 95% CI for categorical data. Results The study cohort consisted of 20 patients (9 female). PSS was confirmed based on dynamic imaging with provocative maneuvers for all patients. Median (range) age at DVT diagnosis was 17 (15-21) years. Thirteen patients were diagnosed at an outside hospital and referred to BCH for further management. Fourteen patients received upfront anticoagulation with low molecular weight heparin of whom 13 patients were transitioned to a DOAC. Six patients were started on DOACs upfront. Fifteen subjects (75%) received upfront endovascular intervention at diagnosis. Median interval between DVT diagnoses to endovascular intervention was 5 (1-118) days. All patients underwent decompressive rib-resection surgery. Median interval between DVT diagnosis and surgery was 12 (7-39) weeks. Three patients (15%) developed major bleeding and 3 (15%) patients developed recurrent/progressive thrombosis after surgery. Two of the 3 patients who developed major bleeding were anticoagulated with a DOAC pre-operatively, which had been held for 48 hours before surgery. All subjects had a planned post-operative venogram, 14 (70%) of whom underwent completion venoplasty. Anticoagulation was discontinued in 18/20 (90%) patients with a median duration of therapy of 19.5 (14-60) weeks. Four patients (20%) were noted to have an underlying thrombophilia (Factor 5 R506Q [2]; Factor 2 G20210A [1]; Protein S deficiency [1]). End-of-therapy imaging was obtained for all patients - 17 (85%) had complete thrombus resolution, while two (10%) had partial thrombus resolution. Seventeen (85%) patients have undergone evaluation for PTS, of whom 12 (71%) were noted to have mild PTS and 2 (12%) have moderate-severe PTS as defined by the modified Villata instrument. Discussion Greater than 90% of pediatric patients with PSS who were treated per our institutional multi-disciplinary protocol had complete or partial thrombus resolution. Additionally, only 12% of patients reported moderate to severe PTS on follow-up and were prescribed sequential compression sleeves. Lastly, DOACs appear to be safe and efficacious in this cohort, though based on our internal data, we now interrupt DOACs for 72 hours before decompressive surgery.

Left ventricular thrombus in patients with heart failure with improved ejection fraction

Abstract Background This study sought to: (1) determine the prevalence of LV thrombus at baseline and at the time of recovered ejection fraction (EF) in patients with heart failure with improved ejection fraction (HF-imp EF), (2) examine clinical and echocardiographic factors associated with the presence of LV thrombus, and (3) determine the prevalence of thromboembolic events when LVEF was improved and oral anticoagulant (OAC) was discontinued. Methods and results Patients with nonischemic HF-imp EF defined as a baseline LVEF of ≤ 40%, a ≥ 10% increase from baseline LVEF, and a second measurement (6 months apart) of LVEF of > 40% were consecutively enrolled in advanced HF clinic in a tertiary center. Patients with recent myocarditis, recent coronary revascularization, active chemotherapy, hypertrophic cardiomyopathy, cardiac amyloidosis, and tachycardia induced cardiomyopathy were excluded. A total of 104 consecutive patients (age 51 ± 15 years; 66% were male) with HF-imp EF were included. Of these, 14 patients (14%) had LV thrombus at baseline. Baseline LVEDD, LVEF, and LV global longitudinal strain (GLS) were 61 ± 10 mm, 23 ± 15%, and -5.9 ± 3.3%, respectively. Younger age, absence of atrial fibrillation, receiving oral diuretics, lower LVEF, reduced LV GLS, and reduced RV free wall (FW) GLS were significantly associated with LV thrombus at baseline (p < 0.05 for all) (Table 1). All patients (100%) with LV thrombus at baseline received oral anticoagulants (OAC). At the median follow-up of 27 months, 14 (100%) had complete resolution of LV thrombus when LVEF > 40%. Of 14 patients, 11 (79%) who were in sinus rhythm discontinued OAC. After a median further follow-up of 27.4 months following OAC discontinuation, there was no thromboembolic event or all-cause mortality in these patients. One of 11 patients developed worsening LVEF and recurrent LV thrombus at 25 months after LVEF improvement (> 40%). Conclusions Approximately 1 in 6 patients with HF-imp EF had LV thrombus at baseline. LV thrombus formation was associated with more impaired LV and RV systolic function and myocardial deformation implicating more thromboembolic milieu. Complete resolution of LV thrombus occurred in all patients who were on OAC therapy at the time of imp-EF. Discontinuation of OAC when LVEF > 40% was safe. However, recurrent thrombus formation can occur when LV systolic function was deteriorated. Annual or bi-annual echocardiographic follow-up may be essential in these patients.

Abstract 12644: FlowTriever Percutaneous Aspiration Thrombectomy: A Promising Approach to Catch a (Throm)Bus In-Transit

Introduction: Clot-in-transit (CIT) is a life-threatening emergency that occurs in about 25,000 patients annually and is associated with high mortality due to rapid cardiopulmonary collapse. This is a case of right atrial (RA) CIT extending from existing IVC filter in a patient with pulmonary embolism (PE) who underwent successful FlowTriever® catheter-based thrombectomy. Description of Case: A 60-year-old male presented with progressively worsening dyspnea on exertion, generalized weakness and fatigue, intermittent chest pain, and right leg pain with immobility for several weeks. He had a history of deep vein thrombosis (DVT), PE in 2008 treated with 18-month of warfarin. IVC filter was placed at that time for unclear indication. His initial labs showed elevated troponin-I of 34 ng/mL and NT pro-BNP of 3542 pg/mL, atrial flutter with 2:1 conduction, incomplete right bundle branch block, and old inferior infarct on ECG. Imaging revealed an extensive bilateral PE with right ventricle (RV) to left ventricle (LV) ratio of 2.3. Transthoracic echocardiogram (TTE) showed global LV dysfunction with ejection fraction of 44%, RV strain, dilated IVC, and an 8.7-cm mobile CIT in IVC extending into RA. Despite being treated with Heparin infusion, patient remained persistently tachycardic and dyspneic. Given his clinical stagnation due to CIT and submassive PE, he underwent an invasive TTE-guided percutaneous IVC and pulmonary arterial thrombectomy using Inari FlowTriever® catheter. Repeated TTE showed complete resolution of atrial thrombus. There was improvement in pulmonary arterial pressure and symptoms immediately post thrombectomy, but atrial flutter persisted. He was eventually discharged the following day with betablocker and life-long duration of anticoagulation. At follow up, he had complete resolution of symptoms and normal sinus rhythm on ECG. Discussion: Although surgical embolectomy is considered first-line therapy, percutaneous thrombectomy should be considered early for CIT to prevent of cardiopulmonary deterioration and shorter hospital course. FlowTriever® is the first device not requiring a cardiopulmonary bypass circuit to be FDA cleared for RA CIT, particularly benefiting patients who are poor surgical candidates.

Recurrent paradoxical cerebral embolism caused by a thrombus entrapped in a patent foramen ovale: a case report

Introduction: A thrombus straddling the patent foramen ovale (PFO) is a very rare clinical entity. Optimal management remains unclear due to the availability of various therapeutic options; thus, an individualized approach is recommended. Case presentation: The authors describe a case presenting with recurrent cerebral embolism and a large and mobile thrombus straddled in the PFO. Historically, cardiac surgery, thrombolysis or anticoagulation were possible management options for this patient. However, there are no guidelines on what the optimal treatment is. Our patient was a poor surgical candidate because of advanced age and multiple comorbidities. Furthermore, she had a recent ischaemic stroke which was a relative contraindication to thrombolysis. After consulting the Heart Team, medical treatment alone with systemic anticoagulation was administered. Subsequent transthoracic echocardiography (TTE) after 1 week showed complete thrombus resolution. After 4 months, the PFO was successfully occluded with an Amplatzer device. The patient received rehabilitation therapy and had good functional recovery. Clinical discussion: Anticoagulant therapy alone was chosen because of high risk for surgery. Complete thrombus resolution was achieved after 1 week although the initial thrombus size was quite large. Nevertheless, this approach may not be applicable to every patient. In addition to TTE, multimodality imaging using transesophageal echocardiography and cardiac magnetic resonance is helpful to identify the mechanism of stroke, which in our case is a thrombus-straddled PFO, and to make early treatment decisions. Serial TTEs help assess the response to anticoagulation. An individualized approach should be made with a multidisciplinary Heart Team. Conclusion: Echocardiography plays an important role in the diagnosis and treatment evaluation for patients with a thrombus straddling a PFO. An individualized approach to manage the patient should be made with a multidisciplinary Heart Team.

Pediatric arterial thrombosis: A single-institution cohort study of patient characteristics and thrombosis outcomes.

Arterial thrombosis (AT) is an increasingly recognized complication in pediatrics. Consensus clinical practice guidelines suggest immediate removal of the indwelling arterial catheter and a short course (5-7 days) of anticoagulation. The optimal duration and modality of antithrombotic therapy in children are yet to be determined. Describe treatment patterns and outcomes in pediatric patients with AT and explore predictors for complete thrombus resolution or long-term complications. Single-institution retrospective study. Patients were identified by ICD-9 and ICD-10 codes for the diagnosis of AT or reports of AT on ultrasound from January 1, 2012, to October 1, 2022. Descriptive and logistic regression analyses were used. 101 patients were included. The median age was 2.2 months. The most common underlying diagnoses were congenital heart disease (39.6%) and infection (22.8%). A majority of patients had symptomatic thrombosis in an extremity, and 78% were catheter-associated. 81% of patients received anticoagulation with a median duration of 35 days. Out of the 70 patients who were treated with anticoagulation alone and had a follow-up imaging, 70% had complete resolution after 90 days of anticoagulation. No clear predictors of complete resolution were identified. Eighteen patients had long-term sequelae secondary to arterial insufficiency. Those with infection-associated AT were more likely to have long-term complications. The major and clinically relevant non-major bleeding rate was 11%. Duration of anticoagulation was widely variable, and 70% of patients achieved complete resolution by 90 days of anticoagulation. A significant proportion of patients developed long-term sequelae secondary to arterial insufficiency. Sepsis/infection at the time of diagnosis with AT was more likely to be associated with long-term complications.

A high rate of post thrombotic complication in pediatric portal vein thrombosis

IntroductionPortal vein thrombosis (PVT) is a rare disease in children and may be complicated by portal hypertension (PH), hepatopulmonary syndrome (HPS) and portopulmonary hypertension (PPHTN) but their incidence and risk factors are unknown. MethodsAn observational, retrospective cohort study of all consecutive children (≤18 years) with PVT treated at the Emma Children's Hospital Amsterdam University Medical Centers between January 1996 and January 2022 was conducted to identify the incidence and risk factors of these post thrombotic complications (PTC) in pediatric patients. ResultsIn total 43/ 703 thrombosis patients had PVT (boys 72.1 %; mean age 1.3 ± 0.5 years). Overall, 51 % of patients developed PH (n = 22), complicated by PPHTN in one of them. In 16 of 22 patients, PVT presented with portal hypertension. Clinically relevant bleeding due to portal hypertension occurred in 13 (59.1 %) patients with PH. The mean age at the first clinically relevant bleeding was 5.1 ± 5.9 years. Risk factors for the development of PH were lack of complete thrombus resolution (OR 24.3, 95 % CI 1.2–7.0; p = 0.008) and unprovoked VTE (OR, 35.4; 95 % CI 1.4–6.3; p = 0.012). Median time from PVT to PH was 137 days (range: 0 days to 5.04 years). ConclusionWe demonstrated that half of the patients develop PH after PVT, with a lack of thrombus resolution and unprovoked VTE as independent risk factors. This high incidence underlines the importance of long-term standardized follow-up of patients after PVT and standard screening in patients at risk of PTC.

Lysis and covered endovascular reconstruction of the aortic bifurcation (LA CERAB) technique for chronic juxtarenal aortic occlusions.

The purpose of this study was to review early experience with catheter directed thrombolysis in the setting of chronic juxtarenal aortic occlusion as an initial therapy to allow safe definitive management with placement of aorto-iliac endografts. A retrospective review was performed of all patients with a diagnosis of chronic juxtarenal aortic occlusion treated by the author with initial catheter directed thrombolysis. In all, six patients (five males and one female, average age of 57 years) treated between 2019 and 2022 met criteria. Total duration of symptoms prior to thrombolysis ranged from 2 to 54 months (average 23 months.) Four patients (67%) had progressed to tissue loss 2 to 5 months prior to the initiation of thrombolysis (average 3.25 months). Radiographic confirmation of aortic occlusion on preoperative imaging was noted 7 to 846 days prior to the initiation of thrombolysis (average 190 days). Five of six patients (83%) had near complete resolution of aorto-iliac thrombus after 12 to 72 hours of thrombolysis to reveal underlying stenoses. The remaining patient's thrombolysis therapy was cut short at 48 hours due to behavioral issues, but had enough clearing of juxtarenal thrombus to undergo placement of aorto-iliac endografts. There were no perioperative deaths, myocardial infarctions, strokes or major complications. Temporary laboratory abnormalities (coagulopathy and/or increase in serum creatinine) were seen in four patients (67%), but all resolved by discharge without clinical sequelae. The primary patency is 100% at early follow-up of up to 15 months. In the setting of chronic juxtarenal aortic occlusions, thrombolysis can provide effective clearing of the juxtarenal aortic thrombus to allow safe definitive therapy with aorto-iliac endografts. The approach deserves consideration in patients at high risk for open reconstruction.

Bi-atrial Thrombi in a Structurally and Functionally Normal Heart; Ticking Time Bomb

We report a case of bi-atrial thrombi traversing the atrioventricular valves in a 72-year-old female with multiple thromboembolic phenomena. Right atrial thrombus can be seen in patients who are immobilized for long period of time and those with deep vein thrombosis and pulmonary embolism. And the left atrial thrombus may present in a case of atrial fibrillation but not common in patients with sinus rhythm. This patient is unique having thrombus in both the atria. She initially presented with ischemic stroke. Echocardiography revealed bi-atrial clots. Later, she developed pulmonary embolism followed by acute right upper limb ischemia. The patient refused all invasive treatments and was managed with anticoagulants only. The patient responded well to therapy with complete thrombus resolution without any significant complications.

Results of a Flexible Patient-Centered Approach to the Timing of Thoracic Outlet Decompression in Paget Schroetter Syndrome

Treatment algorithms for subclavian vein (SCV) effort thrombosis (Paget-Schroetter syndrome- PSS) are multiple, ranging from thrombolysis (TL) with immediate or delayed thoracic outlet decompression (TOD) to conservative treatment with anticoagulation alone. We follow a regimen of TL / pharmacomechanical thrombectomy (PMT) followed by TOD with first rib resection, scalenectomy, venolysis and selective venoplasty (open or endovascular) performed electively at a time convenient for the patient. Oral anticoagulants are prescribed for 3 months or longer based upon response. The aim of this study was to evaluate outcomes of this flexible protocol. Clinical and procedural details of consecutive patients treated for PSS from Jan 2001 to August 2016 were retrospectively reviewed. Endpoints included success of TL and eventual clinical outcome. Patients were divided into two groups-Group I: TL/PMT + TOD; Group II: medical management / anticoagulation + TOD. PSS was diagnosed in 114 patients; 104 (62 female, mean age 31 years) who underwent TOD were included in the study. Group I: 53 patients underwent TOD after initial TL / PMT (23 at our institution and 30 elsewhere) with success (acute thrombus resolution) in 80% (n=20) and 72% (n=24) respectively. Adjunctive balloon-catheter venoplasty was performed in 67%. TL failed to recanalize the occluded SCV in 11% (n=6). Complete thrombus resolution was seen in 9% (n=5). Residual chronic thrombus in 79% (n=42) resulted in median SCV stenosis of 50% (range 10 to 80%). With continued anticoagulation, further thrombus retraction was noted with median 40% improvement in stenosis including in veins with unsuccessful TL. TOD was performed at a median of 1.5 months (range 2 - 8months). Re-thrombosis of the SCV occurred in 3 patients 1-3 days postoperatively and was managed with MT / SCV stenting/balloon angioplasty and anticoagulation. Symptomatic relief was achieved in 49/53 (92%) patients at a median follow up of 14 months. 51 patients underwent TOD following medical treatment elsewhere with anticoagulation alone for an average 6 months (range 2-18 months) with recurrent SCV thrombosis in 5 (11%). Thirty-nine patients (76%) had persistent symptoms; the remaining had asymptomatic compression of the SCV with maneuvers. SCV occlusion persisted in 4 patients (7%); the indication for TOD being residual symptoms from compression of collateral veins, the median residual stenosis was 70% (range 30-90%). TOD was performed at a median of 6 months after diagnosis of PSS. Open venous reconstruction with endovenectomy and patch was performed in 4 patients and stenting in 2. Symptomatic relief was achieved in 46/51 (90%) at a median follow up of 24 months. For Paget Schroetter syndrome a management protocol encompassing elective thoracic outlet decompression at a convenient time following thrombolysis is safe and effective, with low risk of re-thrombosis. Continued anticoagulation in the interim results in further recanalization of the subclavian vein and may reduce the need for open venous reconstruction.

P209 HUGE AND OCCLUDING LAA THROMBUS DISSOLUTION IN A CASE OF SEVERE TACHI–CARDIOMYOPATHY

Abstract A 62–year–old man was admitted to our emergency department for worsening nocturnal dyspnea and orthopnea for 15 days. Finding of Acute Pulmonary Edema in a setting of non datable high ventricular response atrial fibrillation (AF) associated with severe LV dysfunction. NT–proBNP 8.252 pg/ml. ECG: atrial fibrillation with high ventricular response (120/bpm). TTE: Severe left ventricular systolic disfunction (EF 20%). TOE/3D TOE: evidence of voluminous oval–shaped thrombotic formation (10 x 17 mm) protruding in LA and completely occluding the left atrial appendage (LAA). LA thrombosis in patients with AF is relatively rare and represents a contraindication to rhythm control strategies. Once an LAA thrombus is identified, effective anticoagulation is recommended for at least three weeks or until LAA thrombus resolution is detected. Available evidence on left atrial thrombus dissolution largely refers to the use of vitamin K antagonist oral anticoagulant (VKAs), but their effectiveness may be influenced by variability in the level of anticoagulant activity obtained, wich may be suboptimal. In a recent prospective observational study has been evaluated the effectiveness of Edoxaban for the resolution of LA thrombosis in 25 patients with AF: it has been demonstrated a complete thrombus resolution in 56% of patients at 4 weeks, similar to studies using VKAs and the other NOACs. Use of NOACs in this setting represents a great field of interest for the near future. In our experience, indeed, after confirmed diagnosis of LAA thrombus, we started anticoagulant therapy with warfarin (currently the first choice), however due to poor INR control, we switched to continuous infusion of unfractionated heparin (UFH), wich represents, in a hospital setting, a safe and effective method for thrombus dissolution, allowing continuous monitoring of efficacy and a rapid cessation of effect in case of major bleeding. In this way we obtained complete thrombus dissolution in about 3 weeks. At the meantime we initiate a rate control therapy, an optimized treatment for HFrEF and intravenous diuretics. Our experience highlights the need of great ductility in the choice of anticoagulant therapy in patients with evidence of voluminous LAA thrombus, monitoring treatment’s efficacy parameters and being ready to change strategy if necessary and it reminds that auricular thrombosis is often inserted in a wider picture of heart disease wich requires multiple other specifics treatments.

Clinical Profile, Treatment, and Prognosis of Left Ventricular Thrombus in Dilated Cardiomyopathy.

Despite the emerging prevalence of left ventricular (LV) thrombus in dilated cardiomyopathy (DCM), clinical characteristics, management, and disease prognosis are poorly studied. We aim to assess the efficacy/safety profile of direct oral anticoagulants (DOACs) compared to warfarin by evaluating thrombus evolution, risk for stroke and systemic embolism (SSE), heart failure (HF) rehospitalization, all-cause mortality, and major adverse cardiovascular events (MACEs), and determine the impact of thrombus evolution on adverse events. We performed a historical cohort study of patients with a primary diagnosis of DCM and LV thrombus. Relationships between anticoagulants and thrombus resolution were analyzed with the Kaplan-Meier method and Cox regression. Associations between longitudinal thrombus evolution and adverse event hazard were measured with joint modeling. Among 122 patients included, 58.0% were prescribed warfarin, and 42.0% DOACs. Complete thrombus resolution at 90-day-after-index and 180-day-after-index was observed in 93 and 111 patients, with no difference in cumulative resolution between DOACs and warfarin. During a median follow-up of 12.5 months, MACE, all-cause death, SSE, and HF rehospitalization occurred in 42.6%, 27.9%, 4.1%, and 13.9% of patients, comparable in warfarin and DOACs groups. Thrombus persistence was associated with a higher risk of HF rehospitalization. Thrombus progression was associated with poor prognosis, with per unit increment in square-root-transformed thrombus-area resulting in a 1.0691-fold increase in MACE risk and a 1.0546-fold increase in death risk. This study suggests that in DCM patients with LV thrombus, DOACs were comparable to warfarin in thrombus resolution and safety profile. Thrombus persistence or progression was associated with an increased risk of HF rehospitalization, MACE, and mortality.

541 A CASE REPORT OF ACUTE CORONARY SYNDROME: VERY LATE STENT THROMBOSIS DUE TO MAJOR STENT MALAPPOSITION

Abstract Rational The occurrence of stent thrombosis (ST) is a rare event, but it remains one of the most catastrophic complications following percutaneous coronary intervention (PCI). Coronary angiography has limited value in differentiating the causative factors responsible for ST. Technical resolutions We report a case of a 78-year-old male, hypertensive and dyslipidemic who underwent PCI with stenting of the mid left anterior descending artery (LAD) due to chronic coronary syndrome (CCD) two years before. He was admitted to our emergency department for syncopal episode occurred at rest followed by chest pain radiating to the left arm and to the neck. At the time of admission, his electrocardiogram showed diffuse ST-segment elevation in V2-V6 and DI-aVL, therefore patient was urgently sent to the cath lab. Coronary angiography showed LAD occlusion at the proximal edge of the previously implanted stent with TIMI flow grade 0 and TIMI thrombus grade 5. Multiple thrombus aspiration passes were performed with distal flow restoration, followed by intracoronary abciximab administration. After additional thrombus aspiration passes, ST-segment resolution was observed and chest pain improved significantly. OCT imaging of mid-to-proximal LAD was then performed to better characterize the cause of thrombosis. OCT revealed in stent-thrombosis with mixed thrombus (6 mm length, arc >270°) associated with major stent malapposition (maximum malapposition distance: 1.3 mm) at the proximal edge of the previous implanted stent, without evidence of neoatherosclerosis and/or residual disease with unstable features at the stent edges. Additional thrombus aspiration was performed, further reducing the thrombotic burden. As te patient was hemodynamically stable and asymptomatic, with TIMI flow grade 3 at coronary angiography, we decided to start dual antiplatelet therapy (ASA+ticagrelor) plus continuous heparin i.v. infusion, and to defer PCI, planning a control coronary angiography after 72 hours. After 72 hours, OCT revealed almost complete thrombus resolution, and guided PCI with a 4.0/8 mm everolimus-eluting stent in overlap with the previously implanted stent, postdilated with a 4.5 semi-compliant balloon at 18 atm. Revascularization was completed with an OCT-guided PCI of the proximal left circumflex during the same procedure. Clinical implications Our case demonstrates the utility of OCT in determining thrombus burden and assessing the causes of late stent failure, guiding PCI. In this case, OCT was useful as diagnostic tool to identify the mechanism underlying the very-late ST, and as guidance for treatment. It enabled to exclude neoatherosclerosis and/or unstable plaques at stent edges, leaving us more confident to defer PCI after 72 h of antithrombotic therapy. Perspectives The occurrence of ST is rare, but it remains one of the most catastrophic complications following PCI. Coronary angiography has limited value in differentiating the causative factors responsible for ST, while OCT allows to detect and characterize the causes of stent thrombosis (i.e., evaluate thrombus burden, presence of neoatherosclerosis, stent malapposition/underxpansion, uncovred stent struts, significant disease and/or unstable plaques at the stent edges, etc.). A better understanding of the pathophysiological mechanism underlying ST is an important clinical need. The increasing availability of high-resolution intravascular imaging techniques such as OCT provides new opportunities for tailoring treatment strategy and guiding PCI.

Abstract 11101: Q Fever Endocarditis Combined With Thrombus and Antiphospholipid Syndrome

A 63-year-old-man presented to our institution with dyspnea. Transthoracic echocardiography (TTE) showed severe degenerative aortic stenosis with regurgitation and decreased left ventricular contractility. Subsequent transesophageal echocardiography (TEE) and cardiac computed tomography (CT) revealed an outpouching structure at aortomitral intervalvular fibrosa (AMIVF) (Fig A to D), which was compatible with pseudoaneurysm and suggested sequelae of previous infective endocarditis. On surgery, thickened AV leaflets were noted, especially on NCC and LCC (Fig E). When extracting the AV leaflets, subannular pouching was seen without evidence of active inflammation or infection (Fig F). AV replacement with 25-mm Sorin Mitroflow was performed.One-year TTE follow-up showed markedly increased transAV pressure gradient. TEE and cardiac CT revealed symmetric nodular thickening of bioprosthetic AV leaflets with opening limitation (Fig G to J). The patient was admitted on the diagnosis of subclinical bioprosthetic valve thrombosis, and anticoagulation with warfarin and aspirin was started. During the hospitalization, the patient had persistent fever with bicytopenia and hepatosplenomegaly, but repetitive blood cultures were negative. There was no definite fever focus even in 18F-FDG PET CT (Fig K). Since the patient worked on a farm in Dangjin, Chungcheongnam-Do, South Korea, where Q fever is prevalent, an indirect immunofluorescence assay for Coxiella burnetii was conducted and the result turned out to be positive. Additional coagulopathy laboratory findings showed positive for lupus anticoagulant, anti-cardiolipin IgM, and anti-beta2 GPI IgM. Finally, the patient was diagnosed with Q fever endocarditis combined with antiphospholipid syndrome and treated with doxycycline with hydroxychloroquine and maintained anticoagulation. Recent follow-up of TTE and cardiac CT showed complete resolution of prosthetic AV thrombus.

Cardiac resynchronization therapy in treatment of a non-ischemic cardiomyopathy patient with massive left ventricular thrombus

Rationale: Left ventricular thrombosis is a severe and potentially fatal complication of cardiomyopathies with reduced ejection fraction. The mainstay of treatment is anticoagulation, with variable response to thrombus resolution. In patients with reduced ejection fraction and left bundle branch block, cardiac electrical resynchronization is established as a very effective therapy, leading to improvement in left ventricular function. Patient concerns: We present the case of a 64-year-old male with non-ischemic cardiomyopathy with severely reduced ejection fraction and left bundle branch block, who was implanted with a dual-chamber pacemaker in 2018 for sick sinus node disease and who was admitted for progressive shortness of breath. Diagnosis: Echocardiography showed a dilated left ventricle with a severely reduced ejection fraction (15%) and a massive left intraventricular thrombus. Interventions: The patient was started on anticoagulant and heart failure therapy without any response in thrombus size, so as a last resort measure, cardiac resynchronization therapy was added. Outcomes: The 6-month echocardiography follow-up showed a significant improvement in left ventricular function and complete thrombus resolution. Lesson: Cardiac resynchronization therapy promotes reverse remodeling and improves the contraction sequence in the left ventricle, thus eliminating the triggers for thrombosis and aiding in thrombus resolution.

Dabigatran in the treatment and secondary prophylaxis of venous thromboembolism in children with thrombophilia

AbstractIn the phase 2b/3 DIVERSITY trial, 3 months treatment with dabigatran was noninferior to standard of care (SOC) for acute venous thromboembolism (VTE) in children. In a single-arm, phase 3, secondary VTE prevention study, up to 12 months dabigatran use was associated with favorable safety. Dabigatran is approved by the European Medicines Agency and US Food and Drug Administration for pediatric indications. We assessed primary composite efficacy (complete thrombus resolution and freedom from VTE recurrence/VTE-related death) in subgroups with thrombophilia vs those with negative/unknown thrombophilia status in the DIVERSITY trial and safety in both studies. Thrombophilia types were similar between the DIVERSITY trial (total population) and secondary prevention studies: factor V Leiden, 42% vs 33%; prothrombin mutation (G20210A), 19% vs 17%; antithrombin deficiency, 15% vs 20%; protein C/S deficiency, 23% vs 25%; and antiphospholipid antibodies, 18% vs 20% of patients, respectively. In DIVERSITY, 36% and 22% of thrombophilia subgroup patients treated with dabigatran and SOC, respectively, met the primary end point (Mantel-Haenszel–weighted rate difference, −0.135; 95% confidence interval, −0.36 to 0.08; noninferiority P = .0014); comparable to the total DIVERSITY trial population (46% vs 42%) showing dabigatran noninferiority to SOC. Within this subgroup, numerically fewer patients experienced VTE recurrence or progression of index thrombus in the dabigatran treatment group vs SOC. In the secondary prevention study, VTE recurrence at 12 months occurred in 2.8% of patients with thrombophilia vs 0% with negative/unknown thrombophilia. Safety profiles were consistent with those reported previously. Although they should be interpreted with caution, these exploratory findings suggest dabigatran could be an appropriate long-term anticoagulant for children with thrombophilia. These trials were registered at www.clinicaltrials.gov as #NCT01895777 and #NCT02197416.

Acute Intraprocedural Thrombosis After Flow Diverter Stent Implantation: Risk Factors and Relevance of Standard Observation Time for Early Detection and Management

PurposeAcute intraprocedural thrombosis (AIT) is a severe complication of flow diverter stent (FDS) implantation for the treatment of intracranial aneurysms. Even though device-related thromboembolic complications are well known, there are no acknowledged risk factors nor defined surveillance protocols for their early detection. This study aimed to demonstrate that an angiographic active surveillance is effective to detect and treat AIT. Furthermore, we investigated risk factors for the occurrence of AIT.MethodsA prospective institutional protocol consisting of a defined observation period of 30 min following FDS deployment was established to detect AIT. Overall incidence, as well as the efficacy and safety of AIT treatment were assessed. Moreover, radiological and clinical outcomes of patients with AIT were analyzed. The influence of various patient- and procedure-related factors on the occurrence of AIT was investigated using multivariable forward logistic regression.ResultsDuring active surveillance twelve cases of AIT were observed among a total of 161 procedures (incidence: 7.5%). The median time of first observation was 15.5 min (IQR 9.5) after FDS implantation. The early recognition of AIT ensured a prompt treatment with intravenous application of a glycoprotein IIb/IIIa inhibitor, which led to complete thrombus resolution in all cases without hemorrhagic complications. Patients with pre-existing arterial hypertension and side branches originating from the aneurysmal sac had a higher risk of AIT (respectively OR, 9.844; OR, 3.553). There were two cases of re-thrombosis in the short-term postoperative period, of whom one died. The remaining patients with AIT had a good clinical outcome.ConclusionActive surveillance for 30 min after FDS implantation is an effective strategy for early detection and ensuing treatment of AIT and can thus prevent secondary sequalae. Hypertension and side branches originating from the aneurysmal sac may increase the risk of AIT.

Aetiological, clinical and therapeutic prognostic factors for the evolution of deep vein thrombosis followed up with serial venous Doppler ultrasound.

Deep vein thrombosis (DVT) is a dynamic process that can be followed up with Doppler ultrasound (DUS). To evaluate the role of certain factors that can influence the evolution of DVT. In 121 DVT patients (mean age 58.19 ± 14.47 years; 30 with no venous thromboembolism (VTE) identifiable risk factors (RF), 31 with weak RF, 30 with moderate RF and 30 with strong RF), DUS was performed at admission and after 1, 3, 6, 12 and 24 months. Favourable evolution was defined as complete resolution of thrombus, whereas unfavourable evolution was defined as incomplete resolution, thrombosis recurrence or post-thrombotic syndrome. Complete thrombus resolution was found at 1 month (M1) in 24.8% of patients, at 6 months (M6) in 49.6% and at 24 months (M24) in 61.2% of patients. Favourable evolution was seen in younger patients at M1 and M3 (P = 0.004 and P = 0.045) and in cases with earlier treatment (P < 0.0001). In proximal DVT, the risk of non-favourable evolution was higher (4.05 times at M3, 4.23 times at M6 and 4.29 times at M12). Patients with moderate RF had an earlier favourable evolution (40% at M1, 56.67% at M6 and 70% at M24), and patients with strong RF had the lowest rate of thrombus regression (20% at M1, 36.67% at M6 and 43.33% at M24). DVT evolution can last up to 24 months. Older age, strong VTE RF, proximal DVT localisation and late start of therapy constitute unfavourable evolutive prognosis. These cases need closer clinical and DUS monitoring to prevent complications.