Fibrinolysis in left-sided mechanical prosthetic valve thrombosis with high INR

Mechanical prosthetic valve thrombosis: A literature review of treatment strategies

Mechanical prosthetic valve thrombosis (MPVT) is a common complication of valvular implantations. This study compared the efficacy and safety of different treatments for MPVT. A systematic search of electronic databases identified studies evaluating surgical, anticoagulant, and thrombolytic therapies. Although several studies of different types have been conducted to evaluate the efficacy of these treatment strategies the lack of randomized controlled trials has resulted in the inability to make a definitive conclusion about the pros and cons of these treatments. Recent treatments, such as slow and ultraslow infusion of thrombolytics, showed comparable efficacy and lower complication rates than traditional methods. Inadequate anticoagulant use is a major risk factor for MPVT, highlighting the importance of prevention. Treatment selection should be individualized based on patient factors and available expertise. Overall, slow and ultraslow infusion of thrombolytics may be a promising treatment option for MPVT.

Dual mechanical valve thrombosis resolution through thrombolytics: a case series

Background

Prosthetic valve thrombosis (PVT) is a severe complication of mechanical valve replacement. Simultaneous thrombosis of multiple prosthetic valves is rare and is associated with worse outcomes. Treatment options include anticoagulation, thrombolysis, and redo operative valve replacement, with rare reports of adjunctive balloon valvuloplasty. There is limited evidence to guide therapeutic selection, specifically dosing, timing, and duration of thrombolysis. The following case series highlights the importance of successful thrombolytic management in dual PVT with high bleeding risk defined as a coagulopathy with an elevated international normalized ratio greater than 3 and New York Heart Association (NYHA) Class III and IV heart failure.

Case summary

We describe two patients with concomitant aortic and mitral PVT. Both patients presented in NYHA Class III and IV heart failure with different challenges to surgical treatments including high bleeding risk from coagulopathy and history of multiple prior sternotomies. After multi-disciplinary discussions, both patients underwent a combination of low-dose, slow, or ultra-slow infusion of tissue plasminogen activator, with a resolution of their dual PVT seen on cine-fluoroscopy imaging as freely moving mechanical leaflets and improvement of heart failure symptoms back to baseline NYHA Class II or lower.

Discussion

Prosthetic valve thrombosis is a complex medical condition requiring a multi-disciplinary team to evaluate the best course of treatment. A trial of pharmacologic thrombolysis is often the first attempted treatment for obstructive PVT, although surgery is recommended for patients with NYHA IV symptoms, or with contraindications to thrombolysis, including high bleeding risk. However, in patients with high bleeding risk and NYHA Class III and IV heart failure, especially with surgical contraindications, low-dose thrombolytics, with slow or ultra-slow infusions, may still be safe and effective treatment strategies for multi-valve PVT. Further research is needed to guide thrombolysis in multi-valve PVT.

Mechanical valve thrombosis: current management and differences between guidelines

All foreign bodies inserted in the circulatory system are thrombogenic and require temporary or lifelong antithrombotic therapies to prevent thrombosis. The adequate level of anticoagulation during the first few months determines the long-term durability, particularly for mechanical prostheses;2 however also for biological valves. Suboptimal anticoagulation is the most frequent source of mechanical valve thrombosis (MVT). The patient's clinical presentation decides how mechanical prosthetic valve obstruction is managed. If the mechanical valve thrombosis is obstructive and the patient is in a critical condition with hemodynamic instability, an immediate surgical intervention should be performed. The thrombolytic treatment is an option for left mechanical valve thrombosis in patients who have high surgical risk and no contraindications and also for right heart valve thrombosis. In non-obstructive thrombosis on the mechanical valve, patients can be asymptomatic, requiring optimization of the anticoagulant treatment. Both obstructive and non-obstructive thrombus generated on the mechanical prosthesis can result in embolic events. After anticoagulant treatment, if the thrombus persists the indication is for thrombolytic treatment or redo surgery. Pannus can also cause obstruction of the prosthesis for which surgical treatment is the only option. All these clinical scenarios seem to have a simple solution in terms of surgery vs thrombolysis vs effective anticoagulation, but the real-world clinical experience could be different. For example, the same patient with some common comorbidities, non-obstructive mechanical valve thrombosis, and symptomatic only by repeated systemic embolizations, can go through all these 3 therapeutic options, due to MVT's unpredictable nature. Therefore, treatment indications can intersect both on the time axis and depending on the patient's clinical status and the expertise of the center where he is hospitalized. Moreover, the European and American guidelines show subtle but important differences. The aim of this review was to compare these differences, comment on recent studies and evidence gaps, propose a more pragmatic algorithm combining all current indications, and highlight important research directions for this disease that has dominated already the cardiovascular landscape for more than five decades, but for which there have been no significant recent changes in management.

Management of Mechanical Prosthetic Heart Valve Thrombosis: JACC Review Topic of the Week

Mechanical prosthetic heart valves, though more durable than bioprostheses, are more thrombogenic and require lifelong anticoagulation. Mechanical valve dysfunction can be caused by 4 main phenomena: 1) thrombosis; 2) fibrotic pannus ingrowth; 3) degeneration; and 4) endocarditis. Mechanical valve thrombosis (MVT) is a known complication with clinical presentation ranging from incidental imaging finding to cardiogenic shock. Thus, a high index of suspicion and expedited evaluation are essential. Multimodality imaging, including echocardiography, cine-fluoroscopy, and computed tomography, is commonly used to diagnose MVT and follow treatment response. Although surgery is oftentimes required for obstructive MVT, other guideline-recommended therapies include parenteral anticoagulation and thrombolysis. Transcatheter manipulation of stuck mechanical valve leaflet is another treatment option for those with contraindications to thrombolytic therapy or prohibitive surgical risk or as a bridge to surgery. The optimal strategy depends on degree of valve obstruction and the patient's comorbidities and hemodynamic status on presentation.

Mechanical prosthetic valve thrombosis after ChAdOx1-nCoV-19 vaccination: A case report

The ChAdOx1 nCoV-19 adenoviral vector-based vaccine was the first to be approved against COVID-19 in India. Vaccine induced thrombotic thrombocytopenia (VITT) is a rare but serious adverse effect of the ChAdOx1 nCoV-19 vaccine, causing widespread thrombosis and thrombocytopenia. A 22-year-old patient, who had undergone mechanical mitral valve replacement, presented to us one week after administration of 1st dose of the ChAdOx1 nCoV-19 Coronavirus vaccine with acute prosthetic heart valve thrombosis (PVT). Laboratory investigations revealed thrombocytopenia and high D-Dimer levels, suggestive of probable VITT. In this report, we highlight the importance of identification of VITT as a cause of PVT and discuss management options.