Transcatheter Aortic Valve Replacement Thrombosis Research Articles

A Finite Element Analysis Study from 3D CT to Predict Transcatheter Heart Valve Thrombosis.

Background: Transcatheter aortic valve replacement has proved its safety and effectiveness in intermediate- to high-risk and inoperable patients with severe aortic stenosis. However, despite current guideline recommendations, the use of transcatheter aortic valve replacement (TAVR) to treat severe aortic valve stenosis caused by degenerative leaflet thickening and calcification has not been widely adopted in low-risk patients. This reluctance among both cardiac surgeons and cardiologists could be due to concerns regarding clinical and subclinical valve thrombosis. Stent performance alongside increased aortic root and leaflet stresses in surgical bioprostheses has been correlated with complications such as thrombosis, migration and structural valve degeneration. Materials and Methods: Self-expandable catheter-based aortic valve replacement (Medtronic, Minneapolis, MN, USA), which was received by patients who developed transcatheter heart valve thrombosis, was investigated using high-resolution biomodelling from computed tomography scanning. Calcific blocks were extracted from a 250 CT multi-slice image for precise three-dimensional geometry image reconstruction of the root and leaflets. Results: Distortion of the stent was observed with incomplete cranial and caudal expansion of the device. The incomplete deployment of the stent was evident in the presence of uncrushed refractory bulky calcifications. This resulted in incomplete alignment of the device within the aortic root and potential dislodgment. Conclusion: A Finite Element Analysis (FEA) investigation can anticipate the presence of calcified refractory blocks, the deformation of the prosthetic stent and the development of paravalvular orifice, and it may prevent subclinical and clinical TAVR thrombosis. Here we clearly demonstrate that using exact geometry from high-resolution CT scans in association with FEA allows detection of persistent bulky calcifications that may contribute to thrombus formation after TAVR procedure.

Transcatheter aortic valve replacement thrombosis in patient supported with durable left ventricular assist device

Aortic insufficiency (AI) is a frequent problem after continuous-flow left ventricular assist device (LVAD) implantation and results in increased morbidity and mortality. Advances in transcatheter aortic valve replacement (TAVR) technology have resulted in this being discussed as a potential option for LVAD patients with AI. While small case series have been published, we report the first case of TAVR thrombosis in an LVAD patient. This case highlights a major diagnostic and management dilemma that should become more present if this strategy becomes more widespread.

TAVR Thrombosis in Patient Supported with Durable Left Ventricular Assist Device

Introduction Aortic incompetence (AI) is very common complication after continuous flow left ventricular assist device (LVAD) implantation, and can result in increased symptoms for LVAD patients. Recent advances in Transcatheter Aortic Valve Replacement (TAVR) technology has resulted in this becoming a potential therapeutic avenue for LVAD patients with AI. We report a case of TAVR implantation in a patient supported with a LVAD complicated by thrombosis. Case Report A 61-year-old female presented with STEMI. She was treated with primary PCI, but had progressive cardiogenic shock and was placed on VA-ECMO. Due to high PRA, she was unable to be listed for primary transplantation and underwent implantation of a Heartware LVAD (Medtronic) as bridge to decision. Her post-operative course was complicated by recurrent GI bleeding. Over the following 12 months, she was noted to have worsening AI on routine echocardiography, with worsening symptoms that persisted despite hemodynamic and echocardiographic-guided LVAD optimization. After heart team review, her anatomy was deemed appropriate for TAVR and she underwent implant of a 26mm Evolut Pro (Medtronic). The procedure was complicated by post-implant complete heart block on POD #4 requiring pacemaker implantation. She was discharged from the hospital, however over the next 3 months had recurrent episodes of low flow alarms that continued despite LVAD speed and medication optimization. A transthoracic echocardiogram did not reveal any abnormalities, although it was unable to visualize the TAVR leaflets. A multiphase 4D CT Angiogram was performed to rule out LVAD outflow graft obstruction, which revealed extensive hypoattenuating leaflet thickening involving all 3 leaflets of the TAVR with absent leaflet motion consistent with thrombosis of the prosthetic valve leaflets (See Figure). She was started on intravenous anticoagulation (unfractionated heparin), but this had to be ceased due to hemodynamically significant GI bleeding requiring multiple transfusions. LVAD speed was also attempted to be increased to minimize risk of aortic valve opening, but this was unable to be continued due to recurrent low flow LVAD alarms. Repeat imaging 3 months later showed continual thrombosis, and she has remained stable while awaiting transplantation. Summary We describe a novel complication of TAVR in LVAD patients. This case highlights the major diagnostic and management dilemmas that should be considered as this management strategy becomes more widespread in this patient population.

Transcatheter Aortic Valve Replacement Related Thrombosis in a Patient with a Left Ventricular Assist Device

Introduction Transcatheter aortic valve replacement (TAVR) has been reported as treatment for LVAD related aortic insufficiency (AI). However, the risks of this procedure with unique LVAD physiology are not known. This case describes the diagnostic challenges and catastrophic consequences of TAVR related thrombosis in a continuous flow LVAD patient. Case Report A 68 year old male with a history of TAVR, ischemic cardiomyopathy, and VT underwent LVAD implantation as a bridge to decision. The post-op course was complicated by recurrent heart failure and severe LVAD related AI. He underwent valve-in-valve TAVR for LVAD related AI and initial aortography revealed unobstructed flow into the coronary arteries. He developed incessant VT and shock post-operatively. After failure of medical and ablative therapies, he was transferred to our institution for urgent transplant evaluation. He was listed as status 1 for heart transplantation according to current guidelines for life-threatening ventricular arrhythmia. Imaging studies did not raise suspicion for valve related complication. Admission TTE demonstrated moderate RV dysfunction and the TAVR was not well visualized, but it was well seated without regurgitation. Perioperative TEE had limited TAVR evaluation (Figure 1A-B) but there was normal flow across the inflow and outflow cannulas of the LVAD. There was no echo derived aortic valve gradients to cause clinical suspicion for TAVR thrombosis with ischemic complications, so 4D CTA was not obtained. At the time of heart transplantation, the patient was found to have a large aortic root thrombus with extension into the left main coronary artery and a large thrombus extending from the undersurface of the valve causing complete obstruction of the left ventricular outflow tract (Figure 2A-B). Summary We highlight a case of valve-in-valve TAVR related thrombosis as an unexpected cause of VT in LVAD supported patient. Valve thrombosis was not suspected with the available imaging and likely caused the patient's clinical deterioration. The risk of TAVR related complications may be increased in the setting of continuous flow LVAD physiology due to unique flow dynamics and the presence of intermittent or persistent aortic valve closure.

Challenges in Aortic Stenosis: Review of Antiplatelet/Anticoagulant Therapy Management with Transcatheter Aortic Valve Replacement (TAVR): TAVR with Recent PCI, TAVR in the Patient with Atrial Fibrillation, and TAVR Thrombosis Management.

This review aims to describe the current evidence and consensus recommendations around antiplatelet and anticoagulant management in three common clinical scenarios in transcatheter aortic valve replacement (TAVR): (1) recent percutaneous coronary intervention (PCI) preceding TAVR, (2) atrial fibrillation (AF) management in patients undergoing TAVR, and (3) bioprosthetic valve thrombosis management in TAVR. Several small clinical trials have evaluated the use of single vs. dual antiplatelet therapy in patients undergoing TAVR, with most recent data favoring single antiplatelet therapy. There are several trials currently enrolling and in follow-up that evaluate the use of anticoagulants in combination with single and dual antiplatelet therapy for patients with AF undergoing TAVR, but as yet, there is no data to support a clear strategy. The use of DAPT after PCI continues to potentially shorten in patients undergoing elective PCI, thus prolonged DAPT may not be necessary post TAVR for the sake of PCI. Bioprosthetic valve thrombosis occurs more commonly than previously thought, but has uncertain clinical significance. In observational studies, antiplatelet therapy has little effect on bioprosthetic valve thrombosis, whereas anticoagulation is effective in both prevention and treatment of thrombosis. DAPT is currently recommended for 1-6months for all patients without an indication for oral anticoagulation who undergo TAVR; however, there is a growing amount of evidence for single antiplatelet therapy. In the special situation of patients who have recently undergone PCI, the length of DAPT will depend on stent selection (BMS vs. DES), but may not be significantly prolonged unless the patient experienced an acute coronary syndrome prior to TAVR. There is no clear, optimal antithrombotic strategy for patients with AF who undergo TAVR, but avoidance of triple therapy by using OAC and low-dose ASA seems to be reasonable. OAC, not DAPT, is now known to prevent bioprosthetic valve thrombosis in TAVR and SAVR patients; however, the optimal therapy remains unknown. For patients who develop bioprosthetic valve thrombosis, OAC for 3-6months, and repeat imaging is recommended to document resolution.

TCT-650 Clinical Presentation, Management and Outcomes of Patients who developed Post Transcatheter Aortic Valve Replacement Thrombosis: Global Case Series

Current prevalence of thrombus formation after transcatheter aortic valve replacement (TAVR) is small (1-3%). This complication can lead to poor clinical outcomes including re-do procedure and cardiac death. Currently there are no established diagnostic or treatment guidelines. We aimed to report

The Fluid Mechanics of Transcatheter Heart Valve Leaflet Thrombosis in the Neosinus.

Transcatheter heart valve (THV) thrombosis has been increasingly reported. In these studies, thrombus quantification has been based on a 2-dimensional assessment of a 3-dimensional phenomenon. Postprocedural, 4-dimensional, volume-rendered CT data of patients with CoreValve, Evolut R, and SAPIEN 3 transcatheter aortic valve replacement enrolled in the RESOLVE study (Assessment of Transcatheter and Surgical Aortic Bioprosthetic Valve Dysfunction With Multimodality Imaging and Its Treatment with Anticoagulation) were included in this analysis. Patients on anticoagulation were excluded. SAPIEN 3 and CoreValve/Evolut R patients with and without hypoattenuated leaflet thickening were included to study differences between groups. Patients were classified as having THV thrombosis if there was any evidence of hypoattenuated leaflet thickening. Anatomic and THV deployment geometries were analyzed, and thrombus volumes were computed through manual 3-dimensional reconstruction. We aimed to identify and evaluate risk factors that contribute to THV thrombosis through the combination of retrospective clinical data analysis and in vitro imaging in the space between the native and THV leaflets (neosinus). SAPIEN 3 valves with leaflet thrombosis were on average 10% further expanded (by diameter) than those without (95.5±5.2% versus 85.4±3.9%; P<0.001). However, this relationship was not evident with the CoreValve/Evolut R. In CoreValve/Evolut Rs with thrombosis, the thrombus volume increased linearly with implant depth (R2=0.7, P<0.001). This finding was not seen in the SAPIEN 3. The in vitro analysis showed that a supraannular THV deployment resulted in a nearly 7-fold decrease in stagnation zone size (velocities <0.1 m/s) when compared with an intraannular deployment. In addition, the in vitro model indicated that the size of the stagnation zone increased as cardiac output decreased. Although transcatheter aortic valve replacement thrombosis is a multifactorial process involving foreign materials, patient-specific blood chemistry, and complex flow patterns, our study indicates that deployed THV geometry may have implications on the occurrence of thrombosis. In addition, a supraannular neosinus may reduce thrombosis risk because of reduced flow stasis. Although additional prospective studies are needed to further develop strategies for minimizing thrombus burden, these results may help identify patients at higher thrombosis risk and aid in the development of next-generation devices with reduced thrombosis risk.

CRT-600.15 Clinical Presentation, Management and Outcomes of Patients Who Developed Post Transcatheter Aortic Valve Replacement Thrombosis

Current prevalence of thrombus formation after transcatheter aortic valve replacement (TAVR) is small (1-3%). This complication can lead to poor clinical outcomes including re-do procedure and cardiac death. Currently there are no established diagnostic or treatment guidelines. We aimed to report