Thrombolysis as first choice therapy in prosthetic heart valve thrombosis. A study of 68 patients

Monocyte to HDL ratio may predict thrombosis in patients with mechanical mitral and aortic valve prosthesis

Increased inflammatory biomarkers have been reported in prosthetic heart valve thrombosis (PHVT). Monocyte to HDL ratio (MHR) and albumin to CRP levels (CAR) are two biomarkers used widely for systemic inflammation but there is a lack of data on prosthetic heart valves. This study aimed to find out the potential predictive value of MHR and CAR for PHVT. Patients who had the diagnosis of mechanical mitral/aortic PHVT and normally functioning prosthesis were retrospectively analyzed. Laboratory data including complete blood count and biochemistry were recorded. Transesophageal echocardiography was performed to diagnose PHVT. The study included 118 patients with mechanical PHVT and 120 patients with normally functioning prosthesis. White blood count, monocyte levels, C-reactive protein, MHR and CAR were significantly higher whereas the lymphocyte, HDL and INR levels on admission were lower in patients with PHVT. Multivariate analysis showed that as well as inadequate anticoagulation, MHR, but not CAR, was found to be an independent predictor of thrombosis in patients with PHVT. Receiver operating characteristic curve analysis was performed to detect the best cut-off value of MHR in the prediction of thrombosis in patients with prosthetic valves. MHR level of > 12.8 measured on admission, yielded an AUC value of 0.791 [(CI 95% 0.733-0.848 p < 0.001) sensitivity 71%, specificity 70%]. Inadequate anticoagulation is the primary cause that leads to thrombosis in mechanical prosthetic valves. Increased MHR, but not CAR, was also shown to be an independent predictor of thrombosis in patients with mechanical mitral and aortic prosthetic valves.

Surgery compared to fibrinolytic therapy for symptomatic left-sided prosthetic heart valve thrombosis (SAFE-PVT): Rationale and design of a randomized controlled trial

BACKGROUND

Left-sided mechanical prosthetic heart valve thrombosis (PVT) occurs because of suboptimal anticoagulation and is common in low-resource settings. Urgent surgery and fibrinolytic therapy (FT) are the two treatment options available for this condition. Urgent surgery is a high-risk procedure but results in successful restoration of valve function more often and is the treatment of choice in developed countries. In low-resource countries, FT is used as the default treatment strategy, though it is associated with lower success rates and a higher rate of bleeding and embolic complications. There are no randomized trials comparing the two modalities.

METHODS

We performed a single center randomized controlled trial comparing urgent surgery (valve replacement or thrombectomy) with FT (low-dose, slow infusion tissue plasminogen activator, tPA) in patients with symptomatic left-sided PVT. The primary outcome was the occurrence of a complete clinical response, defined as discharge from hospital with completely restored valve function, in the absence of stroke, major bleeding or non-CNS systemic embolism. Outcome assessment was done by investigators blinded to treatment allocation. The principal safety outcome was the occurrence of a composite of in-hospital death, non-fatal stroke, non-fatal major bleed or non-CNS systemic embolism. Outcomes will be assessed both in the intention-to-treat, and in the as-treated population. We will also report outcomes at one year of follow-up. The trial has completed recruitment.

CONCLUSION

This is the first randomized trial to compare urgent surgery with FT for the treatment of left-sided PVT. The results will provide evidence to help clinicians make treatment choices for these patients. (Clinical trial registration: CTRI/2017/10/010159).

Mechanical Aortic Valve Thrombosis Successfully Treated With Intravenous Thrombolytic Therapy: A Case Report

Mechanical prosthetic valves, like all foreign bodies, are thrombogenic, requiring anticoagulation to avoid thrombosis and reduce the risk of catastrophic stroke. We reported a case of a 42-year-old female that developed mechanical valve thrombosis and was successfully treated with low infusion thrombolytic therapy using alteplase (tPA, tissue plasminogen activator).

Chronic thrombosis of bioprostheses: Diagnosis and management

Acquired valvular heart disease is associated with increased mortality and morbidity. While the etiology of the valvular dysfunction determines the mode of treatment, over 100,000 valve operations are performed annually in the US with the use of bioprosthetic valves comprising up to 90%. While bioprosthetic valves do not require life long anticoagulation, the incidence of prosthetic valve thrombosis is continuously increasing. This article reviews the current status on diagnosis, treatment modalities and management of bioprosthetic valve thrombosis.

Thrombolysis or Surgery in Patients With Obstructive Mechanical Valve Thrombosis: The Multicenter HATTUSHA Study

BACKGROUND

Prosthetic valve thrombosis (PVT) is one of the life-threatening complications of prosthetic heart valve replacement. Due to the lack of randomized controlled trials, the optimal treatment of PVT remains controversial between thrombolytic therapy (TT) and surgery.

OBJECTIVES

This study aimed to prospectively evaluate the outcomes of TT and surgery as the first-line treatment strategy in patients with obstructive PVT.

METHODS

A total of 158 obstructive PVT patients (women: 103 [65.2%]; median age 49 years [IQR: 39-60 years]) were enrolled in this multicenter observational prospective study. TT was performed using slow (6 hours) and/or ultraslow (25 hours) infusion of low-dose tissue plasminogen activator (t-PA) (25 mg) mostly in repeated sessions. The primary endpoint of the study was 3-month mortality following TT or surgery.

RESULTS

The initial management strategy was TT in 83 (52.5%) patients and surgery in 75 (47.5%) cases. The success rate of TT was 90.4% with a median t-PA dose of 59 mg (IQR: 37.5-100 mg). The incidences of outcomes in surgery and TT groups were as follows: minor complications (29 [38.7%] and 7 [8.4%], respectively), major complications (31 [41.3%] and 5 [6%], respectively), and the 3-month mortality rate (14 [18.7%] and 2 [2.4%], respectively).

CONCLUSIONS

Low-dose and slow/ultraslow infusion of t-PA were associated with low complications and mortality and high success rates and should be considered as a viable treatment in patients with obstructive PVT.

Fast versus ultra-slow thrombolytic infusion regimens in patients with obstructive mechanical prosthetic valve thrombosis: a pilot randomized clinical trial

BACKGROUND

Thrombolysis is an alternative to surgery for mechanical prosthetic valve thrombosis (MPVT). Randomized clinical trials have yet to test safety and efficacy of a proposed ultraslow thrombolytic infusion regimen.

METHODS AND RESULTS

This single-center, open-label, pilot randomized clinical trial randomized adult patients with acute obstructive MPVT to an ultraslow thrombolytic regimen (25 mg of recombinant tissue-type plasminogen activator [rtPA] infused in 25h) and a fast thrombolytic regimen (50 mg of rtPA infused in 6h). If thrombolysis failed, a repeated dose of 25 mg of rtPA for 6h was administered in both groups up to a cumulative dose of 150 mg or the occurrence of a complication. Primary outcome was a complete MPVT resolution (>75% fall in the obstructive gradient by transthoracic echocardiography, <10° limitation in opening and closing valve motion angles by fluoroscopy, and symptom improvement). Key safety outcome was a BARC type III or V major bleeding. Overall, 120 patients, including 63 (52.5%) women, at a mean age of 36.3±15.3 years, were randomized. Complete thrombolysis success was achieved in 51 patients (85.0%) in the ultraslow-regimen group and 47 patients (78.3%) in the fast-regimen group (OR, 1.58; 95% CI, 0.25 to 1.63; P = 0.34). One case of transient ischemic attack and 3 cases of intracranial hemorrhage (absolute risk difference, -12.5%; 95% CI, -23.1% to -1.0%; P = 0.04). were observed only in the fast-regimen group.

CONCLUSIONS

The ultraslow thrombolytic regimen conferred a high thrombosis resolution rate without major complications. Such findings should be replicated in more adequately powered trials (IRCT20181022041406N2).

Repeat reteplase therapy in a patient with recurrent prosthetic tricuspid valve thrombosis after trido multiple valve replacement

Prosthetic valve thrombosis (PVT) is a rare but life-threatening complication. It has an incidence of 6.1% in developing countries and 0.3%–1.3% in developed countries. The first-line treatment for the right-sided PVT is fibrinolytic therapy with streptokinase or recombinant tissue plasminogen activators, but there are limited cases that were treated with recombinant plasminogen activators. A 57-year-old female with a history of Trido valve surgery and persistent atrial fibrillation rhythm was hospitalized for recurrent tricuspid mechanical valve thrombosis multiple times. The patient was treated with fibrinolytics successfully three times. We report a rare case of recurrent tricuspid mechanical valve thrombosis that is treated with IV reteplase twice.

2020 ACC/AHA Guideline for the Management of Patients With Valvular Heart Disease: Executive Summary: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

This executive summary of the valvular heart disease guideline provides recommendations for clinicians to diagnose and manage valvular heart disease as well as supporting documentation to encourage their use.

METHODS

A comprehensive literature search was conducted from January 1, 2010, to March 1, 2020, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, Cochrane, Agency for Healthcare Research and Quality Reports, and other selected database relevant to this guideline. Structure: Many recommendations from the earlier valvular heart disease guidelines have been updated with new evidence and provides newer options for diagnosis and treatment of valvular heart disease. This summary includes only the recommendations from the full guideline which focus on diagnostic work-up, the timing and choice of surgical and catheter interventions, and recommendations for medical therapy. The reader is referred to the full guideline for graphical flow charts, text, and tables with additional details about the rationale for and implementation of each recommendation, and the evidence tables detailing the data considered in developing these guidelines.

Outcome of thrombolysis with streptokinase in patients with prosthetic valve thrombosis

Objective

To evaluate the outcome of thrombolysis in patients of prosthetic valve thrombosis.

Methods

This retrospective analysis was conducted on data of 84 patients of prosthetic valve thrombosis who presented to emergency room of Faisalabad Institute of Cardiology between July 2017 to December 2019. The diagnosis of prosthetic valve thrombosis was based on clinical suspicion and bed side transthoracic echocardiography done by a consultant cardiologist. Fluoroscopy was done to confirm the diagnosis by observing immobile valve leaflet. The confirmed patients were then treated in emergency with streptokinase after taking an informed consent. Quantitative variables like age were summarized by mean and standard deviation. Qualitative variables like gender, successful thrombolysis, stroke, major bleeding, mortality or re-do surgery were summarized by frequency and percentage.

Results

Mean age was 29 ± 6.36, years and there were more female patients (n=43, 51.25%) as compared to males (n=41, 48.8%). Among the 66 surviving patients thrombolysis was successful without any complications in 56 patients (66.7%). Thrombolysis was successful with minor complications in six patients (7.1%) and it failed to produce desired results in four patients (4.8%). In this study 18 (21.4%) patients died. The common complications included minor bleeding in four patients (4.8%) and major bleeding in 10 patients (12.0 %).

Conclusion

Thrombolysis produces reasonable success rate in cases of prosthetic valve thrombosis who are in functional class I or II. However, it has very high mortality rate in patients presenting with functional class III and IV.

Thrombolytic treatment of prosthetic valve thrombosis: a study using Urokinase

OBJECTIVE

We analysed the efficacy and safety of thrombolytic therapy with urokinase in patients with prosthetic valve thrombosis.

METHODS

Twenty-three patients with valve thrombosis received thrombolytic treatment using urokinase. First, a 250,000 IU intravenous bolus injection was administered as a loading dose, followed by intravenous infusion of 100,000 IU/h for 10 h and anticoagulation with low molecular weight heparin every day. The maximum treatment time was 5 days, i.e., until the transvalvular pressure gradient was normal or close to normal. Transthoracic echocardiography (TTE) was used every 12 h to monitor whether the thrombus was reduced and whether there was haemodynamic improvement. Routine blood tests, the prothrombin time (PT), international normalized ratio (INR) and complications were observed every day.

RESULTS

Sixteen (69.6%) patients were successfully treated with thrombolytic therapy: 2/2 (100%) aortic valves and 14/21 (66.7%) mitral valves. The partial success rate of this study was 13.0% (3/23). Four patients did not show any improvement in haemodynamics. Two cases had slight urine haemorrhage. One patient died of severe cerebral haemorrhage and shock. The overall mortality was 13.0% (3/23), including two patients who died after subsequent surgery.

CONCLUSION

Urokinase is more convenient and successful in the treatment of PVT. More experience may make TT the optimal treatment for PVT, especially in high-risk surgical situations.

Short-Term Clinical Follow-Up After Thrombolytic Therapy in Patients With Prosthetic Valve Thrombosis: A Single-Center Experience

Background

Thrombolytic therapy has evolved as an alternative to surgery for prosthetic valve thrombosis (PVT). Therefore, this retrospective, single-center study aimed to evaluate the clinical profile of PVT and the role of thrombolytic therapy in patients with PVT.

Methods

Data from a total of 16 consecutive patients with PVT enrolled between January 2017 and January 2018 at a tertiary care center in India were retrospectively evaluated. PVT was diagnosed based on clinical presentation, transthoracic echocardiography, and fluoroscopy. All patients received 0.25 MU intravenous (IV) bolus streptokinase over 30 min, followed by a 0.1 MU/h IV infusion for a maximum of 72 h. Transthoracic echocardiography and fluoroscopy were repeated after completion of thrombolysis session. The clinical endpoints were death and hemodynamic success within 24 h of thrombolytic therapy or during the hospital stay, and major complications, including stroke or major bleeding (intracranial bleed or bleeding requiring transfusion or surgical treatment) during the hospital stay and within 3 months of thrombolytic therapy.

Results

The median age of the patients was 40 ± 11.60 years and about 62.5% (n = 10) were females. The median time between the valve placement and presentation for PVT was 3 years (range: 1 - 4 years). The peak gradient across the thrombotic mitral and aortic valve was 43.79 ± 18.47 and 93.5 ± 33.11 mmHg, respectively. At 3 days post-thrombolysis, peak gradient across both mitral valve (15.91 ± 7.56; mean gradient: 8.45 ± 4.01) and aortic valve (23.50 ± 6.45; mean gradient: 13.60 ± 3.83) decreased significantly (P ≤ 0.05). The thrombolytic therapy was successful in 13 (81.25%) patients. While, two (12.50%) patients died, none developed stroke or myocardial infarction during the study period.

Conclusions

The present study with short-term follow-up demonstrated the acceptable clinical efficacy of thrombolytic therapy. However, larger trials with a greater number of patients and longer follow-up are warranted to establish the safety and effectiveness of thrombolytic therapy in patients with PVT.

Prosthetic Mitral Valve Obstruction with Left Atrial Appendage Thrombus: A Therapeutic Dilemma

Valvular obstruction is a rare but life-threatening complication of mechanical prosthetic valves that raises significant challenges in management. We describe a unique case of mechanical mitral valve obstruction with co-existing left atrial appendage (LAA) thrombus. A 48-year-old man with a past medical history of atrial fibrillation and mechanical mitral valve replacement 18 months prior, presented with symptoms of new onset heart failure for 10 days. INR on presentation was sub-therapeutic. Trans-thoracic and trans-esophageal echocardiography revealed prosthetic mitral valve obstruction with mobile, echogenic masses seen on the mechanical valve as well as LAA, suggestive of thrombus. His clinical course rapidly deteriorated and he developed cardiogenic shock. He was deemed to have prohibitive risk for emergent surgical intervention. He received trial of thrombolytic therapy, with partial improvement of hemodynamic parameters and a mild decrease in thrombus burden. He then underwent surgical intervention with a favorable outcome. Intra-operative visualization of the prosthetic valve revealed a combination of pannus and thrombus. Prosthetic valve function should be promptly assessed in patients presenting with heart failure symptoms, as clinical deterioration can be rapid. Acute presentation, history of inadequate anticoagulation and appearance of soft mass on an echocardiogram, are suggestive of thrombus as the etiology of valve obstruction. However, thrombus and pannus are known to frequently co-exist. Emergent surgery is the recommended management strategy in patients with left-sided prosthetic valve thrombosis with the New York Heart Association (NYHA) III or IV symptoms, due to a lower rate of thrombo-embolism, major bleeding, and recurrent prosthetic valve thrombosis when compared with thrombolytic therapy. Slow-infusion, low-dose thrombolytics were recently shown to have favorable outcomes and can be considered when surgery is not available or the patient is deemed to have prohibitive surgical risk.

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

BACKGROUND

A significant number of patients with prosthetic valve thrombosis have a prothrombin time international normalised ratio in the therapeutic range at presentation. Surgery may not be possible in many patients and traditionally a high international normalised ratio is considered a relative contraindication for fibrinolysis.

METHODS

We conducted an observational study in patients with left-sided obstructive prosthetic valve thrombosis with international normalised ratio at or above the therapeutic range at presentation who received fibrinolysis. The fibrinolytic regimens, timing of initiation, success of fibrinolysis, risk of major and minor bleeding and ischaemic stroke were evaluated in the study.

RESULTS

Of 30 patients included in the study 70% received immediate fibrinolysis and in 30% it was delayed. The majority of patients (90%) presented with New York Heart Association class III/IV symptoms. The mean international normalised ratio at fibrinolysis was 3.04 ± 0.70 in the immediate group and 2.42 ± 0.89 in the delayed group. Haemodynamically stable patients who had delayed initiation of fibrinolysis had a trend towards less bleeding without an increase in mortality. The rates of intracranial haemorrhage (0% vs. 7.7%), minor bleeding (12.5% vs. 25.1%) and ischaemic stroke (0% vs. 30.7%) were lower in patients who received low dose infusion compared to a conventional dose.

CONCLUSIONS

Fibrinolysis can be considered in patients with prosthetic valve thrombosis with high international normalised ratio at presentation. For haemodynamically stable patients, delayed initiation of fibrinolysis is associated with a marginally lower bleeding risk without an increase in mortality. Low dose infusion may be considered over a conventional dose as it is associated with a lower incidence of ischaemic stroke and a good rate of valve function restoration with a trend towards less bleeding.

Follow-up and management of valvular heart disease patients with prosthetic valve: a clinical practice guideline for Indian scenario

PURPOSE

Valvular heart disease (VHD) patients after prosthetic valve implantation are at risk of thromboembolic events. Follow-up care of patients with prosthetic valve has a paramount role in reducing the morbidity and mortality. Currently, in India, there is quintessential need to stream line the follow-up care of prosthetic valve patients. This mandates the development of a consensus guideline for the antithrombotic therapy in VHD patients post prosthetic valve implantation.

METHODS

A national level panel was constituted comprising 13 leading cardio care experts in India who thoroughly reviewed the up to date literature, formulated the recommendations, and developed the consensus document. Later on, extensive discussions were held on this draft and the recommendations in 8 regional meetings involving 79 additional experts from the cardio care in India, to arrive at a consensus. The final consensus document is developed relying on the available evidence and/or majority consensus from all the meetings.

RESULTS

The panel recommended vitamin K antagonist (VKA) therapy with individualized target international normalized ratio (INR) in VHD patients after prosthetic valve implantation. The panel opined that management of prosthetic valve complications should be personalized on the basis of type of complications. In addition, the panel recommends to distinguish individuals with various co-morbidities and attend them appropriately.

CONCLUSIONS

Anticoagulant therapy with VKA seems to be an effective option post prosthetic valve implantation in VHD patients. However, the role for non-VKA oral therapy in prosthetic valve patients and the safety and efficacy of novel oral anticoagulants in patients with bioprosthetic valve need to be studied extensively.

A global perspective on mechanical prosthetic heart valve thrombosis: Diagnostic and therapeutic challenges

Prosthetic valve thrombosis is one of the major causes of primary valve failure, which can be life-threatening. Multimodality imaging is necessary for determination of leaflet immobilization, cause of underlying pathology (thrombus versus pannus or both), and whether thrombolytic therapy attempt in the patient would be successful or surgery is needed. Current guidelines for the management of prosthetic valve thrombosis lack definitive class I recommendations due to lack of randomized controlled trials, and usually leave the choice of treatment to the clinician’s experience. In this review, we aimed to summarize the pathogenesis, diagnosis, and management of mechanical prosthetic valve thrombosis.

Prolonged Infusions of Low-Dose Thrombolytics in Elderly Patients With Prosthetic Heart Valve Thrombosis

BACKGROUND

The outcomes of thrombolytic therapy (TT) in elderly patients with prosthetic valve thrombosis (PVT) have not been evaluated previously. We investigated the outcomes of low-dose and slow infusion TT strategies in elderly patients with PVT.

METHODS

Twenty-seven (19 female) patients aged ≥65 years (median: 70 years, range: 65-82 years) were treated with repeated TT agents for PVT. The TT regimens included 24-hour infusion of 1.5 million units of streptokinase in 2 patients, 6-hour infusion of 25 mg recombinant tissue plasminogen activator (t-PA) in 12 patients, and 25-hour infusion of 25 mg t-PA in 13 patients. Treatment success and adverse event rates were assessed.

RESULTS

The initial and cumulative success rates were 40.7% and 85.2%, respectively. Adverse events occurred in 6 (22.2%) patients including 4 (14.8%) major (1 death, 1 rethrombosis, and 2 failed TT) and 2 (7.4%) minor (1 transient ischemic attack and 1 access site hematoma) events. Higher thrombus burden (thrombus area ≥1.1 cm² by receiver operating characteristics analysis, sensitivity: 83.3%, specificity: 85%, area under the curve: 0.86, P = .008) and New York Heart Association class (0% vs 15.4% vs 25% vs 100% for classes I-IV, respectively, P = .02) predicted adverse events. By multiple variable analysis, thrombus area was the only independent predictor of adverse events (odds ratio: 13.8, 95% confidence interval: 1.02-185, P = .04).

CONCLUSION

Slow infusion of low doses of TT agents (mostly t-PA) with repetition is successful and safe in elderly patients with PVT. However, excessive thrombus burden may predict adverse events.

Dysfunction of mechanical heart valve prosthesis: experience with surgical management in 48 patients

BACKGROUND

Dysfunction of mechanical heart valve prostheses is an unusual but potentially lethal complication after mechanical prosthetic valve replacement. We seek to report our experience with mechanical valve dysfunction regarding etiology, surgical techniques and early outcomes.

METHODS

Clinical data of 48 patients with mechanical valve dysfunction surgically treated between October 1996 and June 2011 were analyzed.

RESULTS

Mean age was 43.7±10.9 years and 34 were female (70.8%). The median interval from primary valve implantation to dysfunction was 44.5 months (range, 1 hour to 20 years). There were 21 emergent and 27 elective reoperations. The etiology was thrombosis in 19 cases (39.6%), pannus in 12 (25%), thrombosis and pannus in 11 (22.9%), improper disc orientation in 2 (4.1%), missing leaflet in 1 (2.1%), excessively long knot end in 1 (2.1%), endogenous factor in 1 (2.1%) and unidentified in 1 (2.1%). Surgical procedure was mechanical valve replacement in 37 cases (77.1%), bioprosthetic valve replacement in 7 (14.9%), disc rotation in 2 (4.2%) and excision of excessive knot end in 1 (2.1%). Early deaths occurred in 7 patients (14.6%), due to low cardiac output in 3 (6.3%), multi-organ failure in 2 (4.2%) and refractory ventricular fibrillation in 2 (4.2%). Complications occurred in 10 patients (20.8%).

CONCLUSIONS

Surgical management of mechanical valve dysfunction is associated with significant mortality and morbidity. Earlier identification and prompt reoperation are vital to achieving better clinical outcomes. The high incidence of thrombosis in this series highlights the need for adequate anticoagulation and regular follow-up after mechanical valve replacement.

Assessment of Anti-Tissue Type Plasminogen Activator Antibodies in Patients With Prosthetic Heart Valve Thrombosis: The ATA Trial

BACKGROUND

Thrombolysis is an effective treatment strategy for prosthetic valve thrombosis (PVT). Recombinant tissue-type plasminogen activator (rt-PA) is widely used as a thrombolytic agent. Infusion of rt-PA may trigger the production of anti-tissue plasminogen activator (tPA) antibodies (ATAs). We aimed to evaluate the possible relationship between ATA levels and PVT formation, and the role of baseline ATA levels on outcomes of thrombolytic therapy in patients with PVT.

METHODS

This prospective, single-center cohort study included 28 patients with PVT undergoing thrombolysis and 31 controls with normal prostheses. Plasma samples were collected from patients with PVT at baseline and at 15th, 30th, 90th, and 180th days after thrombolysis and from controls at baseline only. The ATA levels were assessed in human plasma by an enzyme-linked immunosorbent assay.

RESULTS

Baseline ATA-immunoglobulin (Ig) G and IgM were significantly higher in patients with PVT than in controls. The levels of IgM and IgG peaked at 15th and 30th days after rt-PA infusion, respectively. Subtherapeutic international normalized ratio and baseline ATA-IgM were independent predictors of PVT. Thrombolysis failed in 6 patients (21%) in whom baseline IgM levels were significantly higher than successfully lysed patients. Rethrombosis occurred in 9 patients (32%) in whom baseline IgG levels were significantly higher than those without rethrombosis. There was a moderate positive correlation between baseline and 15th-day IgM levels and the dose of rt-PA needed for successful lysis.

CONCLUSION

The ATA levels tended to be higher in patients with PVT at the time of initial diagnosis compared to controls without PVT. In addition, such patients with PVT and high ATA levels may be at high risk for failed thrombolysis or rethrombosis.

Treatment of Prosthetic Valve Thrombosis: Current Evidence and Future Directions

Prosthetic heart valve thrombosis (PVT) is a rare but serious complication with high morbidity and mortality. The optimal treatment of the PVT is controversial and depends on thrombus location and size, the patient’s functional class, the risk of surgery or thrombolysis, and the clinician’s experience. Although surgical therapy has been the traditional therapeutic approach, studies with low-dose and slow-infusion rates of thrombolytic agents have revealed excellent results. This article reviews the various treatment options in patient with PVT.

Bioprostethic mitral valve thrombosis due to oral contraceptive drug use and management with ultra-slow thrombolytic therapy

Prosthetic valve thrombosis is a severe complication, which usually occurs in inadequately anticoagulated patients. Mechanical valve thrombosis is more common than bioprosthetic valve thrombosis (BVT). Oral contraceptive drugs are associated with increased risk of thromboembolism in women. The possible association between oral contraceptive drug use and BVT has never been reported before. We present a case of obstructive BVT occurring after the use of an oral contraceptive drug and successful management with ultra-slow thrombolytic therapy.

Ultraslow thrombolytic therapy: A novel strategy in the management of PROsthetic MEchanical valve Thrombosis and the prEdictors of outcomE: The Ultra-slow PROMETEE trial

BACKGROUND

Low-dose (25mg), slow infusion (6hours) of tissue-type plasminogen activator (t-PA) with repetition as needed has been shown to provide effective and safer thrombolysis in patients with prosthetic valve thrombosis (PVT). Further prolonging the infusion time may be rational with regard to reducing complication rates without reducing success rates. We aimed to investigate the efficacy and safety of ultraslow (25hours) infusion of low-dose (25mg) alteplase (t-PA) for PVT.

METHODS AND RESULTS

Transesophageal echocardiography-guided thrombolytic therapy (TT) was administered to 114 patients with PVT in 120 different episodes between 2009 and 2013 in a single center. Prosthetic valve thrombosis was obstructive in 77 (64.2%) and nonobstructive in 43 (35.8%) episodes. Ultraslow infusion (25hours) of low-dose (25mg) t-PA, as the TT regimen, was used in all patients admitted with PVT. The end points were thrombolytic success, mortality, and complication rates. The overall success rate of TT was 90% (95% CI 0.85-0.95). The univariate predictors of an unsuccessful result were higher New York Heart Association (NYHA) class, thrombus cross-sectional area, duration of suboptimal anticoagulation, lower baseline valve area, and presence of atrial fibrillation. The NYHA class was the only independent predictor of TT failure by multiple variable analysis. The overall complication rate was 6.7% (3.3% nonfatal major, 2.5% minor, and 0.8% death). The predictors of complications were presence of atrial fibrillation, higher NYHA class, and thrombus area.

CONCLUSION

Ultraslow (25hours) infusion of low-dose (25mg) t-PA without bolus appears to be associated with quite low nonfatal complications and mortality for PVT patients without loss of effectiveness, except for those with NYHA class IV.

Successful fibrinolytic treatment of prosthetic heart valve thrombosis using streptokinase

OBJECTIVES

This study aims to evaluate the clinical outcome of fibrinolytic treatment of prosthetic valve thrombosis (PVT) with 'streptokinase' as a first line treatment for these cases.

METHODS

The study group was 20 consecutive patients (10 females) diagnosed with PVT. The protocol for streptokinase administration was either accelerated (intravenous infusion of 0.5 million IU over 30 minutes followed by 0.15 million IU/h) or conventional (intravenous infusion of 0.25 million IU over 30 minutes followed by 0.15 million IU/h). Success of fibrinolytic therapy was defined as complete restoration of valve function in the presence or absence of complications.

RESULTS

Eighteen patients (90%) had mitral PVT and two (10%) had aortic PVT. Thrombolytic therapy with streptokinase was successful in all but one case, with a total mortality of four cases (20%). In PVT episodes, before streptokinase therapy, the prosthetic valve areas (in all cases, mitral and aortic positions) were 0.82 ± 0.21, 0.83 ± 0.21, and 0.73 ± 0.18 cm²; and the peak and mean transvalvular gradients were 38.7 ± 16.7 and 25.4 ± 8.7, 34.1 ± 8.8 and 23.2 ± 5.4, and 80.0 ± 14.1 and 45.0 ± 7.1 mmHg, respectively. After streptokinase therapy, the prosthetic valve area and peak and mean transvalvular gradients improved significantly (for all cases, mitral and aortic positions: valve area 2.17 ± 0.58, 2.21 ± 0.61, and 1.85 ± 0.07 cm², peak gradient 18.7 ± 11.0, 16.4 ± 7.7, and 39.0 ± 18.4, and mean gradient 9.6 ± 7.1, 8.2 ± 5.3, and 22.0 ± 11.3 mmHg, respectively; paired t-test, P<0.001 for pre- versus post-streptokinase infusion for all variables).

CONCLUSION

Fibrinolytic therapy using streptokinase was an effective therapeutic strategy for the management of PVT and is a reasonable alternative to surgery.

Visualization of thrombosis on a prosthetic pulmonary valve using electrocardiogram-gated multidetector computed tomography

We report a case of prosthetic valve thrombosis in an 18-year-old man. Total surgical repair of tetralogy of Fallot was performed at 3 years of age. At the age of 18, he underwent pulmonary valve replacement because of exacerbating pulmonary trunk obstruction. After surgery, valve malfunction was suspected. We attempted to employ electrocardiogram (ECG)-gated multidetector computed tomography (MDCT). The stuck valve was clearly visualized together with a thrombus within. Thrombolytic therapy was undertaken on these findings. ECG-gated MDCT allowed us to make a definitive diagnosis of valve thrombosis as the cause of valve malfunction, which led us to avoid surgical reintervention.

Production of recombinant streptokinase from Streptococcus pyogenes isolate and its potential for thrombolytic therapy

Objectives:

To produce an effective recombinant streptokinase (rSK) from pathogenic Streptococcus pyogenes isolate in yeast, and evaluate its potential for thrombolytic therapy.

Methods:

This study was conducted from November 2012 to December 2013 at King Khalid University, Abha, Kingdom of Saudi Arabia (KSA). Throat swabs collected from 45 pharyngitis patients in Asser Central Hospital, Abha, KSA were used to isolate Streptococcus pyogenes. The bacterial DNA was used for amplification of the streptokinase gene (1200 bp). The gene was cloned and in vitro transcribed in an eukaryotic expression vector that was transformed into yeast Pichia pastoris SMD1168, and the rSK protein was purified and tested for its thrombolytic activity.

Results:

The Streptococcus pyogenes strain was isolated and its DNA nucleotide sequence revealed similarity to other Streptococcus pyogenes in the Gene bank. Sequencing of the amplified gene based on DNA nucleotide sequence revealed a SK gene closely related to other SK genes in the Gene bank. However, based on deduced amino acids sequence, the gene formed a separate cluster different from clusters formed by other examined genes, suggesting a new bacterial isolate and accordingly a new gene. The purified protein showed 82% clot lysis compared to a commercial SK (81%) at an enzyme concentration of 2000 U/ml.

Conclusion:

The present yeast rSK showed similar thrombolytic activity in vitro as that of a commercial SK, suggesting its potential for thrombolytic therapy and large scale production.

Thrombolytic therapy or surgery for valve prosthesis thrombosis: systematic review and meta-analysis

BACKGROUND

Prosthetic heart valve thrombosis is a life-threatening condition for which treatment has not been evaluated by randomized trials.

OBJECTIVES

To compare surgery with thrombolytic therapy for the treatment of prosthetic valve thrombosis.

METHODS

A comprehensive systematic review was carried out by independent researchers using PubMed, Web of Knowledge, HINARI, LILACS and EMBASE, including papers indexed up to 23 October 2013 with at least 10 patients, evaluating one or both treatment options. Outcomes of interest were death, stroke, bleeding, embolic events and success. Study quality was assessed by the Newcastle-Ottawa Scale (ranges from 0 to 9). Comprehensive Meta Analysis Software was used to pool study results, for publication bias analysis and for meta-regression.

RESULTS

Forty-eight studies were included (2302 patients). No randomized study was identified, and all were observational in design. Study quality varied from 4 to 6 stars using the Newcastle-Ottawa Scale. Mortality for surgery was 18.1% (95%CI, 14.6-22.1; I(2) , 62% [42-75]), while mortality for thrombolytic therapy was 6.6% (95% CI, 4.8-8.9; I(2) , 0% [0-13]). Surgical mortality appeared to increase with NYHA-class, according to meta-regression. Other results related to surgery and thrombolytic therapy, respectively, were: embolic events, 4.6% (2.9-7.3) and 12.8% (10.8-15.2); stroke, 4.3%,(2.7-6.6%) and 5.6%,(4.3-7.4%); success rate, 81.9% (77.2-85.8) and 80.7% (75.6-85.0); bleeding, 4.6% (2.9-7.1) and 6.8% (5.4-8.6); and death or stroke, 19.0% (14.8-24.2) and 11.4% (8.7-14.7).

CONCLUSION

Mortality in patients treated by thrombolytic therapy for valve prosthesis thrombosis is significantly lower than in patients treated surgically. As we cannot yet ascertain whether this difference is due to the treatment alone, more studies are now necessary to further clarify these findings.