Intravenous thrombolytic treatment of mechanical prosthetic valve thrombosis: a study using serial transesophageal echocardiography

Management of prosthetic valve thrombosis with unfractionated heparin

BACKGROUND

Prosthetic valve thrombosis (PVT) is a severe and life-threatening complication. Surgery and thrombolytic therapy (TT) carry a high risk, and in several circumstances, optimal anticoagulation with unfractionated heparin (UFH) infusion may be an alternative treatment. This study aimed to assess the results of UFH in patients diagnosed with both obstructive and non-obstructive PVT.

METHODS

This observational retrospective study enrolled patients who had contraindications for TT and surgery underwent UFH therapy.

RESULTS

A total of 136 patients were enrolled [male: 55 (40.4%), mean age: 50.3 ± 14.6 years] in the study. In the successful group, 66 patients (48,5%) showed >75% regression in the thrombus burden without facing death or major non-fatal complications.In the unsuccessful group, 56 had less than a 50% reduction in thrombus load and 14 (10.3%) suffered major complications. The presence of obstruction (27.1% vs. 12.1%; p = 0.028), thrombus area 1.1 cm2 vs. 0.8 cm2; p = 0.005] and the duration of UFH treatment (15.1 vs. 11.8 (days); p = 0.005) were significantly higher in the unsuccessful UFH group.In multivariate regression analyses the presence of obstruction (RR: 3.088, p = 0.020), increased thrombus area (RR: 2.400; p = 0.015), and increased duration of UFH therapy (RR: 1.073 95%, p = 0.012) were identified as independent predictive parameters for a failed UFH therapy.

CONCLUSIONS

This study suggests that UFH therapy may be considered a relatively beneficial treatment strategy for some patients with PVT. The most significant factors affecting success are the obstructive nature and area of the thrombus.

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).

Diagnosis of Left-Sided Mechanical Prosthetic Valve Thrombosis: A Pictorial Review

Although transcatheter valve therapy is rapidly evolving, surgical valve replacement is still required in many patients with severe left-side valve stenosis or regurgitation, the mechanical bi-leaflet heart valve being the standard prosthesis type in younger patients. Moreover, the prevalence of valvular heart disease is steadily increasing, especially in industrialized countries, and the problem of lifelong efficient anticoagulation of these patients remains fundamental, especially in the context where vitamin K antagonists continue to be the current standard of anticoagulation despite a level of oscillating anticoagulation. In this setting, avoiding prosthetic valve thrombosis after surgery is the number one objective for both the patient and the responsible physicians. Although rare, this complication is life threatening, with the sudden onset of acute cardiac failure such as acute pulmonary edema, cardiogenic shock, or sudden cardiac death and inadequate anticoagulation remaining the leading cause of prosthesis thrombosis, along with other risk factors. The availability of multimodal imaging techniques enables and encompasses to a full extent the diagnosis of mechanical valve thrombosis. The gold-standard diagnostic methods are transthoracic and transesophageal echocardiography. Moreover, 3D ultrasound has undoubted value in giving a more accurate description of the thrombus's extension. When transthoracic and transesophageal echocardiography are uncertain, the multidetector computer tomography examination is an important complementary imaging method. Fluoroscopy is also an excellent tool for evaluating the mobility of prosthetic discs. Each method complements the other to differentiate an acute mechanical valve thrombosis from other prosthetic valve pathologies such as pannus formation or infective endocarditis and aids the physician in accurately establishing the treatment method (surgical or pharmaceutical) and its optimal timing. The aim of this pictorial review was to discuss from an imagistic perspective the mechanical prosthetic aortic and mitral valve thrombosis and to provide an overview of the essential role of non-invasive exploration in the treatment of this severe complication.

Reversal of Total Artificial Heart Mechanical Valve Thrombosis Using Catheter-Directed Thrombolysis

Total artificial heart is associated with increased incidence of thromboembolism, which can prove to be fatal. The presence of four metallic tilting discs increases the chances of thrombus formation and sudden obstruction of the valve in a closed position resulting in severe hemodynamic collapse. Such a condition is conventionally treated by a surgical approach for device change; however, this procedure is extremely high risk and associated with complications and poor outcomes. We describe two total artificial heart patients with sudden obstruction to the filling of the right side due to fixing of the atrioventricular valve in a closed position due to a thrombus. After a quick diagnosis by rescue transesophageal echocardiography, we successfully treated these patients with catheter-directed thrombolysis with minimal adverse outcomes. We propose a carefully weighed application of this approach in hemodynamically unstable patients too tenuous for a timely surgery and with low risk for bleeding.

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).

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).

The value of brain natriuretic peptide in the prosthetic valve thrombosis

: We aimed to investigate how prosthetic valve thrombosis (PVT) affects brain natriuretic peptide (BNP) levels and how BNP changes following thrombolytic therapy. The study included 70 consecutive patients with left-sided mechanical PVT who received thrombolytic therapy. The patients were divided into two groups, namely obstructive thrombus (n = 42) and nonobstructive thrombus (NOT, n = 28). BNP levels of patients were assessed before and after thrombolytic therapy. BNP levels were higher in obstructive thrombus group than NOT group in whole study population, in patients with mitral PVT and in patients with aortic PVT [325.0 (189.5-496.0) vs. 84.0 (44.5-140.0), P < 0.001, 323.0 (193-449.0) vs. 59.0 (37.0-131.0), P < 0.001 and 321.0 (132.0-525.0) vs. 99.0 (60.5-173.0), P < 0.001]. BNP levels were positively correlated with transmitral and transaortic mean gradients, and negatively correlated with mitral valve area (r: 0.374, P = 0.013; r: 0.432, P = 0.035 and; r: -0.642, P < 0.001, respectively). BNP values above 165 pg/ml may predict the presence of obstructive thrombus with a sensitivity of 88.0%, and a specificity of 79.0% (AUC = 0.928, 95% confidence interval: 0.871-0.986, P < 0.001). Following thrombolytic therapy, BNP levels (pg/ml) significantly decreased from 325.0 (189.5-496.0) to 137.0 (101.7-224.5), P < 0.001, in all patients with obstructive thrombus, from 323.0 (193.0-449.0) to 129.0 (98.0-223.0), P < 0.001, in patients with only mitral obstructive thrombus and from 321.0 (132.0-525.0) to 181.0 (99.0-217.5), P < 0.001, in patients with only aortic obstructive thrombus. BNP levels are significantly higher in prosthetic valve patients with obstructive thrombus than in those with NOT and decrease in patients with obstructive thrombus after thrombolytic therapy. A cut off value of BNP of at least 165.0 pg/ml was found to discriminate obstructive thrombus from NOT.

Value of Computed Tomography Radiomic Features for Differentiation of Periprosthetic Mass in Patients With Suspected Prosthetic Valve Obstruction

Background:

We aimed to determine whether quantitative computed tomography radiomic features can aid in differentiating between the causes of prosthetic valve obstruction (PVO) in patients who had undergone prosthetic valve replacement.

Methods:

This retrospective study included 39 periprosthetic masses in 34 patients who underwent cardiac computed tomography scan from January 2014 to August 2017 and were clinically suspected as PVO. The cause of PVO was assessed by redo-surgery and follow-up imaging as standard reference, and classified as pannus, thrombus, or vegetation. Visual analysis was performed to assess the possible cause of PVO on axial and valve-dedicated views. Computed tomography radiomic analysis of periprosthetic masses was performed and radiomic features were extracted. The advantage of radiomic score compared with visual analysis for differentiation of pannus from other abnormalities was assessed.

Results:

Of 39 masses, there were 20 cases of pannus, 11 of thrombus, and 8 of vegetation on final diagnosis. The radiomic score was significantly higher in the pannus group compared with nonpannus group (mean, −0.156±0.422 versus −0.883±0.474; P <0.001). The area under the curve of radiomic score for diagnosis of pannus was 0.876 (95% CI, 0.731–0.960). Combination of radiomic score and visual analysis showed a better performance for the differentiation of pannus than visual analysis alone.

Conclusions:

Compared with visual analysis, computed tomography radiomic features may have added value for differentiating pannus from thrombus or vegetation in patients with suspected PVO.

Thrombolysis and surgery for mitral prosthetic valve thrombosis: 11-year outcomes

Background

Mechanical mitral valve obstruction is a serious and life-threatening complication. Treatment is either thrombolysis or reoperation, with both interventions having its own merits and drawbacks. This study aimed to analyze the outcomes of both interventions at a single tertiary referral center.

Methods

From January 2005 to December 2010, 127 patients with mechanical mitral valve obstruction were retrospectively analyzed and divided into a thrombolysis group ( n = 66) and a reoperation group ( n = 61), based on our institute’s inclusion and exclusion criteria. A heart valve team comprising a cardiologist, a surgeon, and the patient was involved in the decision-making, based on the criteria for thrombolysis and reoperation in our institute. The patients had a maximum follow-up period of 14 years (mean 11.2 years). The analysis was divided into in hospital (within 30 days) and follow-up outcomes.

Results

At the end of 10 years, the reoperation group had significantly greater freedom from embolism (100% vs. 95.4% ± 0.7%), bleeding events (94.5% ± 0.8% vs. 89.2% ± 0.4%), and reintervention (96.4% ± 0.5% vs. 92.3% ± 2.3%) as well as better actuarial survival (97.4% ± 1.2% vs. 92.3% ± 0.4%) compared to the thrombolysis group. The complete failure rate of thrombolysis was 12%. The thrombolysis group had shorter intensive care unit and hospital stays.

Conclusion

Reoperation has significant advantages over thrombolysis in terms of embolic and bleeding complications and reintervention. Hence one should consider surgery for stuck mechanical mitral valves, with thrombolysis being useful in a specific subset of patients.

Safety and Efficacy of Repeated Thrombolysis with Alteplase in Early Recurrent Ischemic Stroke: A Systematic Review

BACKGROUND AND AIM

The current American Heart Association guidelines for the management of acute ischemic stroke advise against the use of intravenous (IV) alteplase in patients with recurrent stroke occurring within 90 days of their index event. Following these guidelines strictly, patients having early recurrent ischemic stroke would be unable to avail of this reperfusion strategy that has been proven to confer superior clinical outcomes. While some registry-based studies have demonstrated the safety of IV alteplase in this subgroup of patients, data on the repeated use of the drug are lacking. Thus, we aim to determine the safety and efficacy of repeated thrombolysis in patients with early recurrent ischemic strokes.

METHODS

The following electronic databases were searched for relevant studies: the Cochrane Central Register for Controlled Trials by The Cochrane Library, MEDLINE by PubMed, Health Research and Development Information Network, Scopus, and ClinicalTrials.gov. Data on symptomatic intracranial hemorrhage, 90-day clinical outcomes, systemic hemorrhage and allergic reactionswere synthesized.

RESULTS

Ten articles with 33 patients in total were included in our review. One patient developed symptomatic intracranial hemorrhage after the second reperfusion attempt and subsequently died from pneumonia. Another died from spontaneous rupture of previously unidentified infrarenal aortic aneurysm. Six of the 13 patients with available follow-up data had good clinical outcomes (Modified Rankin Score 0-2). There were no allergic reactions and other drug-related adverse events noted.

CONCLUSIONS

Repeated IV alteplase can be safe and efficacious in patients who have early recurrent ischemic stroke. Larger studies, trials, or registry-based data are needed to ascertain the encouraging findings of our review.

Rivaroxaban versus Warfarin in Patients with Mechanical Heart Valve: Rationale and Design of the RIWA Study

Introduction

Mechanical heart valves (MHV) are extremely durable, but they require permanent use of anticoagulation to prevent thromboembolic events. The only approved therapeutic options are vitamin K antagonists (VKAs), such as warfarin. As a drug class, clinical management is difficult, therefore new alternatives need to be evaluated.

Methods

RIWA is a phase II/III, prospective, open-label, randomized, pilot study designed to investigate oral rivaroxaban 15 mg twice daily compared with dose-adjusted warfarin for the prevention of stroke (ischemic or hemorrhagic) and systemic embolism in patients with MHV, from August 2018 to December 2019. Patients will undergo transesophageal echocardiography at the beginning and the end of the study (follow-up time 90 days). On an explanatory basis, all events will be analyzed, including stroke, peripheral systemic embolism, valve thrombosis, significant bleeding and death.

Discussion

Warfarin and similar VKAs are standard therapy for patients with an MHV. Even with the appropriate use of therapy, the incidence of thromboembolic events is high at 1–4% per year. Furthermore, bleeding risk is significant, ranging from 2 to 9% per year. The new frontier to be overcome in relation to use of the new oral anticoagulants is undoubtedly in patients with MHV. A significant portion of people with MHV worldwide will benefit if noninferiority of these new agents is confirmed.

Trial Registration

ClinicalTrials.gov identifier: NCT03566303. Recruitment Status: Recruiting. First Posted: 25 June 2018. Last Update Posted: 25 June 2018.

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.

The relationship between heparanase levels, thrombus burden and thromboembolism in patients receiving unfractionated heparin treatment for prosthetic valve thrombosis

INTRODUCTION

Procoagulant activity of heparanase has been recently described in several arterial and venous thrombotic disorders. In this study, we aimed to investigate the role of heparanase with regard to thrombus burden, thromboembolism, and treatment success with unfractionated heparin (UFH) in patients with prosthetic valve thrombosis (PVT).

METHODS

This study enrolled 79 PVT patients who received UFH for PVT and 82 controls. Plasma samples which were collected from patients both at baseline and after the UFH treatment and from controls at baseline only, were tested for heparanase levels by heparanase enzyme-linked immunosorbent assay.

RESULTS

The PVT group included 18 obstructive and 61 non-obstructive PVT patients who received UFH infusions for a median duration of 15 (7-20) days. The UFH treatment was successful in 37 (46.8%) patients. Baseline heparanase levels were significantly higher in the patient group than in the controls [0.29 (0.21-0.71) vs. 0.25 (0.17-0.33) ng/mL; p = 0.002]. Baseline heparanase levels were significantly higher in obstructive PVT patients. There was a significant increase in heparanase levels after UFH treatment. Post-UFH heparanase levels were higher in patients who experienced treatment failure compared to successfully treated group. Baseline and post-UFH heparanase levels were significantly higher in patients with a thrombus area ≥1 cm² and with a recent history of thromboembolism.

CONCLUSIONS

Increased heparanase levels may be one of the esoteric causes for PVT. UFH treatment may trigger an increase in heparanase levels which may affect the treatment success. Increased heparanase levels may be associated with high risk of thromboembolism and increased thrombus burden in PVT patients.

The predictive value of the CHA2DS2-VASc score in patients with mechanical mitral valve thrombosis

Prosthetic valve thrombosis (PVT) is a potentially life-threatening complication associated with high morbidity and mortality. The CHA2DS2-VASc is a clinical score used to determine thromboembolism risk in non-valvular atrial fibrillation patients. Therefore; in this study, we aimed to determine predictive value of the CHA2DS2-VASc score for development of PVT in patients with mechanical prosthetic valve. This was a retrospective study included 417 consecutive patients with mechanic prosthetic valve in whom transesophageal echocardiography (TEE) was performed due to different clinical indications from January 2004 to June 2016. After evaluation according to exclusion criteria, 267 patients with mechanic prosthetic valve were enrolled in the study. The definitive diagnosis of the PVT was made as proposed by TEE finding. The study population was divided into two groups; PVT patients (154 patients) and control group (113 patients) with functional prosthetic valve. The CHA2DS2-VASc score was calculated for each patient from the hospital electronic database. The mechanical mitral valve thrombosis predictive value of variables including CHA2DS2-VASc score was tested in our study. The mean CHA2DS2-VASc score was significantly higher in PVT patients compared to control patients (2.51 ± 1.54 vs. 1.13 ± 1.21, p < 0.01). Both on univariate and multivariate analysis demonstrated that the CHA2DS2-VASc score is independently associated with PVT (p < 0.001 and p < 0.001, respectively). The patients whose CHA2DS2-VASc score ≥ 1-3 had 6.20 times higher risk for thrombus formation, and patients whose CHA2DS2-VASc score ≥ 4 had 16.6 times higher risk for thrombus formation compared to patients with CHA2DS2-VASc score = 0 (p < 0.001 and p < 0.001, respectively). The CHA2DS2-VASc score may be a significant independent predictor of PVT in patients with prosthetic valve and the CHA2DS2-VASc score ≥ 2.5 or more was associated with increased PVT in patients with prosthetic valve. Thus; it may be an applicable risk scoring system to assess the risk of development of PVT in patients with prosthetic valve.

Status of the Epicardial Coronary Arteries in Non-ST Elevation Acute Coronary Syndrome in Patients with Mechanical Prosthetic Heart Valves (from the TROIA-ACS Trial)

Coronary thromboembolism (CE) is a rare cause of prosthetic valve derived complications. This study investigates the diagnosis and treatment strategies for non-ST elevation acute coronary syndrome (NSTEACS) in patients with prosthetic heart valves. Forty-eight NSTEACS patients with prosthetic heart valves (mitral:27; aortic:14; mitral+aortic:7) were included in this study. All patients underwent transthoracic and transesophageal echocardiographic examination and coronary angiography. Normal coronary angiographic findings, or visible trombus in one of the coronary arteries, international normalized ratio <2, concomitant prosthetic valve thrombosis (PVT) and absence of multivessel atherosclerotic disease favored CE rather than atherothrombosis. Thrombolytic therapy (TT) with low-dose slow-infusion of tissue type plasminogen activator was used in patients with suspected CE and/or PVT. Coronary angiography demonstrated normal coronary arteries in 26 patients, CE in 16 patients and coronary atherosclerosis in 6 patients. Transesophageal echocardiography revealed obstructive PVT in 9 and nonobstructive PVT in 28 patients whereas 11 patients had normally functioning prostheses. TT was administered to 24 patients with PVT and/or CE. In these patients, TT was successful in 19 patients, partially successful in 4 patients and failed in 1 patient. In conclusion, NSTEACS in patients with prosthetic heart valves is more likely to be associated with PVT derived CE rather than atherosclerosis. TT with low-dose slow infusion of type plasminogen activator has proved its efficacy and safety in patients with CE and/or PVT.

Tenecteplase versus streptokinase thrombolytic therapy in patients with mitral prosthetic valve thrombosis

Objective

Prosthetic valve thrombosis (PVT) is a dreadful complication of mechanical prosthetic valves. Thrombolytic therapy (TT) for PVT is an alternative to surgery and currently making a leading role. This study compares TT with tenecteplase (TNK) and streptokinase (SK) head to head in patients with mitral PVT.

Methods

In this single center, observational study, patients with mitral PVT diagnosed by clinical data, transthoracic echocardiography, transesophageal echocardiography, and fluoroscopy were included. After excluding patients with contraindications for thrombolysis, they were randomly assigned to receive either SK or TNK regimen. Patients were monitored for success or failure of TT and for any complications.

Results

Among 52 episodes (47 patients with 5 recurrences) of mechanical mitral PVT, 40 patients were thrombolyzed with SK and 12 patients were thrombolyzed with TNK. Baseline characteristics including demographic profile, clinical and echocardiographic features, and valve types were not statistically significant between the groups. Complete success rate was 77.5% in SK group and 75% in TNK group (p = 0.88). Partial success rate, failure rate, and major complications were not statistically significant between the two groups. Within 12 h of therapy, TNK showed complete success in 33.3% of patients compared to 15% in SK group (p-value <0.02). Minor bleeding was more common in TNK group.

Conclusion

Slow infusion of TNK is equally efficacious but more effective than SK in the management of mitral mechanical PVT. 75% to 77.5% of PVT patients completely recovered from TT and it should be the first line therapy where the immediate surgical options were remote.

Mechanical Wenckebach Phenomenon in Thrombosed Tricuspid Valve Prosthesis

•

Mechanical valve thrombosis is a serious complication.

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Echocardiography and fluoroscopy are cornerstones of diagnosis.

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Echocardiography in more than two loops can identify intermittent valve obstruction.

AB0 blood types: impact on development of prosthetic mechanical valve thrombosis

Objective:

The non-O alleles of the ABO genotype have been associated with an increased risk of thrombosis. We aimed to assess the association between blood group status and prosthetic valve thrombosis.

Methods:

The association between AB0 blood group status and prosthetic valve thrombosis was assessed in this retrospective study. Transesophageal echocardiography was performed in 149 patients with a diagnosis of prosthetic valve thrombosis and in 192 control subjects.

Results:

Non-0 blood group type (p<0.001), presence of NYHA class III-IV status (p<0.001), and central nervous system (p<0.001) and non-central nervous system (p<0.001) emboli were significantly more prevalent in prosthetic valve thrombosis patients than in the control subjects. The incidence of ineffective anticoagulation was higher in patients with prosthetic valve thrombosis than in controls (p<0.001), as was the presence of moderate to severe left atrial spontaneous echo contrast (p<0.001). The non-0 blood prosthetic valve thrombosis subgroup had a higher incidence of obstructive thrombi and central nervous system thrombotic events than having 0 blood prosthetic valve thrombosis subgroup. Non-0 blood group, ineffective anticoagulation, left atrial spontaneous echo contrast, and a poor NYHA functional capacity were identified to be the predictors of prosthetic valve thrombosis.

Conclusion:

Our data demonstrate that patients with non-0 compared with 0 blood groups have higher incidence of prosthetic valve thrombosis and central nervous system embolism and similar rates of non-central nervous system embolism at presentation compared with 0 blood group type. Thus, non-O blood group may be a risk factor that may be prone to the development of prosthetic valve thrombosis in patients with prosthetic heart valves.

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.

Fibrinolytic Treatment after Transient Ischaemic Attack Caused by Prosthetic Mitral Valve Thrombosis

Prosthetic valve thrombosis is one of the most severe complications after surgical valve replacement. There are many possible presentations: from asymptomatic to life-threatening complications. We report on a 61-year-old female patient with prosthetic replacement of the aortic and mitral valve in the in-house department of cardiac surgery 3 months ago. The patient was suffering from aphasia during 5 minutes in domesticity. After her presentation in the emergency room, the echocardiographic examination revealed a thrombotic formation of the prosthetic mitral valve. At presentation, the anticoagulation was outside the effective range (INR: 1.7). A successful thrombolytic therapy with the plasminogen activator urokinase was begun with complete resolution of the thrombus.

Scientific Rationale for the Inclusion and Exclusion Criteria for Intravenous Alteplase in Acute Ischemic Stroke

Purpose—

To critically review and evaluate the science behind individual eligibility criteria (indication/inclusion and contraindications/exclusion criteria) for intravenous recombinant tissue-type plasminogen activator (alteplase) treatment in acute ischemic stroke. This will allow us to better inform stroke providers of quantitative and qualitative risks associated with alteplase administration under selected commonly and uncommonly encountered clinical circumstances and to identify future research priorities concerning these eligibility criteria, which could potentially expand the safe and judicious use of alteplase and improve outcomes after stroke.

Methods—

Writing group members were nominated by the committee chair on the basis of their previous work in relevant topic areas and were approved by the American Heart Association Stroke Council’s Scientific Statement Oversight Committee and the American Heart Association’s Manuscript Oversight Committee. The writers used systematic literature reviews, references to published clinical and epidemiology studies, morbidity and mortality reports, clinical and public health guidelines, authoritative statements, personal files, and expert opinion to summarize existing evidence and to indicate gaps in current knowledge and, when appropriate, formulated recommendations using standard American Heart Association criteria. All members of the writing group had the opportunity to comment on and approved the final version of this document. The document underwent extensive American Heart Association internal peer review, Stroke Council Leadership review, and Scientific Statements Oversight Committee review before consideration and approval by the American Heart Association Science Advisory and Coordinating Committee.

Results—

After a review of the current literature, it was clearly evident that the levels of evidence supporting individual exclusion criteria for intravenous alteplase vary widely. Several exclusionary criteria have already undergone extensive scientific study such as the clear benefit of alteplase treatment in elderly stroke patients, those with severe stroke, those with diabetes mellitus and hyperglycemia, and those with minor early ischemic changes evident on computed tomography. Some exclusions such as recent intracranial surgery are likely based on common sense and sound judgment and are unlikely to ever be subjected to a randomized, clinical trial to evaluate safety. Most other contraindications or warnings range somewhere in between. However, the differential impact of each exclusion criterion varies not only with the evidence base behind it but also with the frequency of the exclusion within the stroke population, the probability of coexistence of multiple exclusion factors in a single patient, and the variation in practice among treating clinicians.

Mechanical valve obstruction: Review of diagnostic and treatment strategies

Prosthetic valve obstruction (PVO) is a rare but feared complication of mechanical valve replacement. Diagnostic evaluation should focus on differentiating prosthetic valve thrombosis (PVT) from pannus formation, as their treatment options differ. History of sub-optimal anti-coagulation and post-op time course to development of PVO are useful clinical characteristics in differentiating thrombus from pannus formation. Treatment of PVT is influenced by the patient’s symptoms, valve location, degree of obstruction and thrombus size and may include thrombolysis or surgical intervention. Alternatively, pannus formation requires surgical intervention. The purpose of this article is to review the pathophysiology, epidemiology, diagnostic approach and treatment options for aortic and mitral valve PVO.

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.

Thrombolytic Therapy for Right-Sided Mechanical Pulmonic and Tricuspid Valves: The Largest Survival Analysis to Date

Data regarding thrombolytic treatment of right-sided mechanical valve thrombosis are almost nonexistent, and all current guidelines arise from very small case series. We retrospectively studied the in-hospital and long-term outcome data of a larger series of patients who had received, from September 2005 through June 2012, thrombolytic therapy for right-sided mechanical pulmonary valve or tricuspid valve thrombosis. We identified 16 patients aged 8-67 years who had undergone thrombolytic therapy for definite thrombotic mechanical valve obstruction in the tricuspid or pulmonary valve position (8 in each position). All study patients except one had subtherapeutic international normalized ratios. The 8 patients with pulmonary mechanical valve thrombosis had a 100% response rate to thrombolytic therapy, and their in-hospital survival rate was also 100%. The 8 patients with tricuspid mechanical valve thrombosis had a 75% response rate to thrombolytic therapy, with an in-hospital survival rate of 87.5%. The one-year survival rate for mechanical valve thrombosis treated with thrombolytic therapy (whether pulmonary or tricuspid) was 87.5%. On the basis of our data, we recommend that thrombolytic therapy remain the first-line therapy for right-sided mechanical valve thrombosis in adults or children-including children with complex congenital heart disease and patients with mechanical pulmonary valve thrombosis. Surgery should be reserved for patients in whom this treatment fails.

Non-obstructive prosthetic heart valve thrombosis (NOPVT): Really a benign entity?

AIMS

To assess the effectiveness of different treatment strategies in patients with non-obstructive prosthetic valve thrombosis (NOPVT) during hospitalization and long-term follow-up.

METHODS

NOPVT was diagnosed by transesophageal echocardiography. Resolution was defined as the disappearance or reduction of the thrombus under anticoagulation. All cases were first managed with optimization of anticoagulation. At discharge, patients received oral anticoagulation (OAC) alone or OAC and antiplatelet therapy (double treatment). Adverse events were defined as cardiovascular death, recurrence, thromboembolic events or major bleeding.

RESULTS

From 1997 to 2012, 47 patients (mean age: 65years; women: 60%) were diagnosed with NOPVT (mitral valve: 97%). Previous poor anticoagulation control was documented in 66% of patients. Twenty-one patients (45%) were treated with unfractionated heparin (UFH), especially those with thrombus size >10mm (19/21). Optimization of OAC was performed in the remaining patients. Treatment failed in 13 (27.6%) patients, mostly in those who received UFH (10/13), requiring surgery (53.8%) or fibrinolysis (30.7%). Forty-two patients survived and, at discharge, 44% of patients received OAC alone and 56% the double treatment. At follow-up (median 23months; range 0.03-116months), 59.5% of patients presented cardiovascular events, however no differences in outcome were observed with double treatment or OAC alone (p=0.385).

CONCLUSIONS

NOPVT is a high-risk complication, not only during hospitalization but also during follow-up. Optimization of anticoagulation is efficient in most patients except in thrombi ≥10mm treated with UFH. The double treatment does not prevent adverse events or complications during follow-up.

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.

Effect of a combined anti-thrombotic therapy of thrombosis on prosthetic heart valves

OBJECTIVE

To evaluate the curative effects and risks of a medical therapy with combined anti-thrombotic agents for thrombosis on prosthetic heart valves.

METHODS

Twenty-two patients who suffered from thrombosis on prosthetic valves with stable hemodynamics were divided into the inpatient group and the outpatient group. Thrombosis on the valves were demonstrated by transesophageal echocardiographies (TEE). A combined anti-thrombotic therapy with clopidogrel and warfarin were prescribed for all the patients during the whole treatment. Low molecular weight heparin (LMWH) was given twice daily during the first 5 days for the inpatients. The patients accepted regular follow-ups for observation of the functions of prosthetic valves, changes of thrombi, coagulation status and general clinical status.

RESULTS

There were 5 men and 17 women. Thirteen patients suffered from thrombosis on the mechanical mitral valves (MVs), five on the mechanical tricuspid valves (TVs), one on the mechanical aortic valve and tricuspid bio-prosthetic valve, one on the mechanical aortic valve, one on the mitral bio-prosthetic valve, and one on the tricuspid bio-prosthetic valve. After an average of 36.4±23.1 days' observation, 16 (73%) patients' valvular function recovered normal without TTE detectable thrombi, 6 (27%) patients' valvular function remained abnormal including three patients without TTE detectable thrombi during follow-ups. No significant differences of thrombi changes and period of thrombi disappearance were observed between the inpatient group and the outpatient group. For patients with mitral thrombosis, sizes of the left atriums (LAs) decreased an average of 4.1 mm after treatment (95% CI, 1.2-6.9 mm). No significant changes of other chambers and left ventricular ejection fractions (LVEF) were observed. For patients with tricuspid thrombosis, LVEF improved an average of 10.5% after treatment (95% CI, 0.1-17.9%). No significant changes of chambers were observed. None experienced major bleedings except for two cases of mild subcutaneous ecchymoses.

CONCLUSIONS

The combined anti-thrombotic therapy based on clopidogrel and warfarin is a feasible treatment for thrombosis on prosthetic heart valves under a close monitoring.

Obstructed bi-leaflet prosthetic mitral valve imaging with real-time three-dimensional transesophageal echocardiography

Real-time three-dimensional transesophageal echocardiography (RT3D-TEE) can provide unique visualization and better understanding of the relationship among cardiac structures. Here, we report the case of an 85-year-old woman with an obstructed mitral prosthetic valve diagnosed promptly by RT3D-TEE, which clearly showed a leaflet stuck in the closed position. The opening and closing angles of the valve leaflets measured by RT3D-TEE were compatible with those measured by fluoroscopy. Moreover, RT3D-TEE revealed, in the ring of the prosthetic valve, thrombi that were not visible on fluoroscopy. RT3D-TEE might be a valuable diagnostic technique for prosthetic mitral valve thrombosis.

Usefulness of novel hematologic inflammatory parameters to predict prosthetic mitral valve thrombosis

Prosthetic valve thrombosis (PVT) is a life-threatening complication. Neutrophil/lymphocyte ratio (NLR) and platelet/lymphocyte ratio (PLR) have been studied as inflammatory biomarkers in atherosclerosis, but data regarding valvular disease are lacking. The study population included patients with mitral PVT (n = 152) versus control subjects (n = 164) with functional mitral prosthesis. Transesophageal echocardiography was performed to diagnose PVT. NLR and PLR were calculated using complete blood count. C-reactive protein (CRP) levels were also analyzed. Neutrophil and platelet levels did not differ between the groups (4.9 ± 2.0 vs 4.7 ± 1.5, p = 0.84 and 254.8 ± 89.7 vs 241.5 ± 62.8 p = 0.36, respectively), but lymphocyte levels were significantly lower in patients with PVT than the controls (1.8 ± 0.7 vs 2.2 ± 0.6, p <0.001). NLR, PLR, and CRP levels were significantly higher in patients with PVT than in controls (3.2 ± 2.1 vs 2.2 ± 0.8, p <0.001; 163 ± 77.5 vs 114.9 ± 37.3, p <0.001; and 1.97 ± 3.02 vs 1.02 ± 1.22, p = 0.01, respectively). A positive correlation was observed between NLR and PLR (r = 528, p <0.001). NLR level of >2.23, measured on admission, yielded an area under the curve value of 0.659 (95% confidence interval 0.582 to 0.736, sensitivity 66%, specificity 60%, p <0.001) and PLR level of >117.78 yielded an area under the curve value of 0.707 (95% confidence interval 0.636 to 0.777, sensitivity 70%, specificity 58%, p <0.001). Multivariate analysis showed that increased PLR and inadequate anticoagulation were independent predictors of thrombosis in patients with PVT. In conclusion, patients with PVT had increased NLR, PLR, and CRP levels compared with subjects with normofunctional prosthesis, and increased PLR was an independent predictor of mitral PVT.

Role of anticardiolipin antibodies in the pathogenesis of prosthetic valve thrombosis: An observational study

BACKGROUND

Prosthetic valve thrombosis (PVT) is serious complication of valvular replacement surgery, and increased levels of anticardiolipin antibodies (aCL) are associated with thrombosis. The aim of this study was to evaluate the role of aCL in the development of PVT.

PATIENTS AND METHODS

We studied the aCL IgM and IgG levels in 114 patients with PVT and 80 healthy patients with prosthetic valves without PVT or a history of thrombosis. All patients underwent detailed transthoracic, transesophageal echocardiographic and clinical examinations. Blood samples were obtained after transesophageal echocardiography. Tests were repeated 12 weeks apart in patients with aCL IgM or IgG positivity.

RESULTS

The mean age, sex, presence of atrial fibrillation and cardiovascular risk factors, elapsed time after surgery, and prosthetic valve type and location were similar between patients with PVT and those without. Ineffective anticoagulation was significantly higher among patients with PVT (p < 0.001). The aCL IgM values were significantly higher and positive (> 40 MPL) in the PVT group compared with the control group (10.58 ± 15.90 MPL to 3.70 ± 2.30 MPL, p < 0.001; 7.0 to 0 %, p = 0.016, respectively). The aCL IgG values were significantly higher and positive (> 40 GPL) in the PVT group compared with the control group (12.04 ± 17.58 GPL to 3.83 ± 2.56 GPL, p < 0.001 and 7.9 to 0 %, p = 0.01, respectively). According to international consensus documents, 16 patients had antiphospholipid syndrome. Ineffective anticoagulation and aCL IgM and IgG positivity were independent predictors of PVT in logistic regression analysis (multivariate r(2)= 0.648; p < 0.001, OR= 21.405, 95 %CI= 8.201-55.872; p = 0.008, OR= 1.322, % 95CI= 1.076-1.626; p = 0.005, OR= 1.288, 95 %CI= 1.079-1.538).

CONCLUSION

Since the presence of aCL IgM and IgG positivity may cause a tendency toward PVT, these values should be examined in all patients with PVT.

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

BACKGROUND AND OBJECTIVES

Valvular thrombosis is a serious complication in patients with prosthetic heart valves. Traditional treatment is emergency surgery, but thrombolysis provides a non invasive alternative. In this paper we evaluate the efficacy and safety of thrombolysis in prosthetic heart valve thrombosis.

METHODS

Data of 68 patients diagnosed of prosthetic valve thrombosis, treated at the Institute of Cardiology and Cardiovascular Surgery, Havana during a 6-years period were analyzed. They received thrombolysis with a recombinant streptokinase infusion at 250,000 IU in 30 minutes followed by 100,000 IU/hour during 72 hours or less if the thrombosis resolved before. The evaluation was based on clinical and echocardiographic findings.

RESULTS

Affected sites were mitral (50 cases), tricuspid (9), and aortic (9). Mean time of prosthesis implantation was 6.8 years. The presentation form was generally heart failure (NYHA functional class III-IV) in 64 (94.1%) patients. Mean time interval between onset of symptoms and diagnosis was 10.6 days. There was total response to treatment in 58 (85.3%) patients, partial in 4 (5.9%) and failure in 6 (8.8%). Recombinant streptokinase overall dose was 5.1 x 10(6) IU and mean infusion time 50 hours. Major hemorrhagic complications were observed in two patients. Five embolic events occurred during thrombolysis. Four patients died. Rethrombosis was noted in 11 patients; 10 were retreated successfully with thrombolysis.

CONCLUSIONS

Thrombolysis with recombinant streptokinase is efficacious and safe for the treatment of prosthetic heart valve thrombosis. It does not contraindicate surgical treatment if there is no total response, because patient goes to surgery in better hemodynamic conditions with lower risk. Nowadays it can be considered as first-line treatment in all patients with prosthetic heart valve thrombosis regardless of functional class unless specific contraindications exist.

Bivalirudin for treatment of aortic valve thrombosis after left ventricular assist device implantation

Ventricular assist devices are increasingly being used for mechanical support in patients with advanced heart failure. However, thromboembolism remains a leading cause of mortality in this population. We describe the successful treatment of native aortic valve thrombosis with bivalirudin in a patient with factor V Leiden mutation, who had undergone left ventricular assist device implantation, preventing the need for further surgical intervention.