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

Mechanical prosthetic valve thrombosis: A literature review of treatment strategies

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

Mechanical valve thrombosis: current management and differences between guidelines

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

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

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

Thrombolysis for Cardiogenic Shock Secondary to Aortic Bioprosthetic Valve-in-Valve Thrombosis

Valvular obstruction and thromboembolism are feared complications of bioprosthetic valve thrombosis. We describe the case of an 81-year-old man with a prior aortic valve-in-valve bioprosthesis who presented in cardiogenic shock, requiring mechanical circulatory support. He was found to have acute bioprosthetic valve thrombosis and was treated with systemic thrombolysis. This case highlights the overall uncertainty regarding the optimal treatment of acute bioprosthetic valve thrombosis. Society guidelines and the current evidence behind prophylaxis and treatment are reviewed. Although the data remain sparse, systemic thrombolysis may be an effective strategy in critically ill patients who are poor surgical candidates.

Comparison between surgery and fibrinolytic therapy in prosthetic valve thrombosis: A systematic review and meta-analysis

BACKGROUND

Prosthetic valve thrombosis (PVT) is a rare but life-threatening complication. Surgery and fibrinolytic therapy (FT) are the two main treatment options for PVT. The choice between surgery and FT has always been a matter of debate. Previous studies have shown that although the mortality rate is higher in surgery, complications are less frequent than in FT. We aimed to perform a systematic review and meta-analysis to compare the results of surgery and FT in PVT.

METHODS

A systematic review of the literature was performed through Medline, Embase, Scopus, and Web of Science, encompassing all studies comparing surgery and FT in PVT. The rate of each complication and risk ratio (RR) of complications in surgery and FT were assessed using random-effects models.

RESULTS

Fifteen studies with 1235 patients were included in the meta-analysis. The pooled risk of the mortality was not significantly different between FT and surgery in patients with PVT (pooled RR = 0.78, 95% confidence interval [CI]: 0.38-1.60, I² = 61.4%). The pooled risks of thromboembolic events (pooled RR = 4.70, 95% CI: 1.83-12.07, I² = 49.6%) and major bleeding (pooled RR = 2.45, 95% CI: 1.09-5.50, I² = 41.1%) and PVT recurrence (pooled RR = 2.06 95% CI: 1.29-3.27, I² = 0.0%) were significantly higher in patients who received FT.

CONCLUSION

Surgery may be safer and with fewer complications than FT for PVT treatment. However, randomized clinical trials are needed to determine the proper treatment for PVT.

Effectiveness of alteplase infusion for the management of prosthetic mitral valve thrombosis in paediatric age group and proposed algorithm

INTRODUCTION

The incidence of prosthetic valve implantation is increasing in the paediatric population. Prosthetic valve thrombosis leading to obstruction could potentially be a life-threatening complication. There is a debate regarding optimal management of this complication, and there is limited use of thrombolytic therapy in childhood in the setting of valve thrombosis.

OBJECTIVE

We aim to share our experience of successfully using fibrinolytic therapy in terms of alteplase for paediatric prosthetic mitral valve thrombosis and to propose a management algorithm.

METHODS

This retrospective analysis of the database was conducted at our hospital including patients who underwent thrombolysis (alteplase) for prosthetic mitral valve thrombosis from June, 2011 to June, 2021. A total of 10 patients with 20 attempts of alteplase infusion were found in our record.

RESULTS

Alteplase was successful in 19 attempts to relieve valve thrombosis. The safe and effective dose of alteplase was between 0.1 and 0.3 mg/kg/hour. There were no associated major bleeding complications and alteplase was administered either by central or peripheral line.

CONCLUSION

Thrombolysis by alteplase infusion was found to be successful in relief of prosthetic mitral valve thrombosis in paediatric population without major bleeding complications.

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.

Complementary role of cardiac CT in the diagnosis and management of mechanical aortic valve thrombosis with a novel low-dose, ultraslow thrombolysis treatment strategy

A 31-year-old man presented to our emergency department with a 3-day history of progressive breathlessness, fatigue and exertional angina. His history included a mechanical aortic valve replacement (mAVR) for rheumatic heart disease at age 19 years. He could no longer afford medication prescription costs and consequently had not taken oral anticoagulation for 2 months. Transthoracic echocardiography (TTE) demonstrated mechanical prosthetic valve obstruction (PVO) and severe left ventricular (LV) systolic dysfunction; however, valve visualisation was limited by mAVR-related artefact. The patient declined transoesophageal echocardiography. Valve haemodynamics failed to improve despite a prolonged course of parenteral anticoagulation. Multidetector cardiac CT scan was performed which confirmed prosthetic valve thrombosis. A novel low-dose, ultraslow thrombolysis regimen was administered to mitigate the associated bleeding and embolic stroke risk. The patient made an excellent recovery and was discharged on day 30, with repeat cardiac CT scan showing complete resolution of mechanical PVO and normalisation of valve and LV function on TTE.

Detection of Mechanical Prosthetic Valve Dysfunction

The long-term outcome of mechanical aortic and mitral prosthetic valve (A-PV, M-PV) dysfunction (PVD) remains a serious complication associated with high morbidity and mortality. We sought to evaluate the incremental diagnostic value of combined transthoracic echocardiography (TTE) and fluoroscopy (F) in patients with suspected PVD. A total of 354 patients (178 A-PV, 176 M-PV) were imaged by TTE and F within 5 days of hospital admission. PVD was confirmed by transesophageal echocardiography, computed tomography, effective thrombolysis, or surgical inspection. PVD was confirmed in 101 patients (57%) with M-PV and 99 (55%) with A-PV. Regardless of the mechanism of PVD, TTE shows good sensitivity and specificity, with accuracy of 80% for M-PV and 91% for A-PV. F shows high specificity, but low sensitivity with accuracy of 68% for M-PV and 78% for A-PV. The integration of TTE + F significantly improved accuracy both for M-PV (83%) and A-PV (96%). At ROC analysis, the combined model of TTE + F showed the highest area under the curve for the detection of PVD compared with TTE and F alone (p < 0.001). In conclusion, in patients with a clinical suspicion of PVD, the combined model of TTE + F offers incremental value over TTE or F alone. This multimodality imaging approach overcomes limitations of TTE or F alone and provides prompt identification of patients who may require further imaging assessment and/or closer follow up.

[Valve thrombosis and thrombolytic therapy in modern era: a case report]

Prosthetic valve thrombosis is a feared complication with an annual incidence ranging between 0.3 to 1.3%. Diagnostic approach is essential for a better prognosis and ultimately determines the chosen therapeutic strategy. Emergent valvular surgery is usually recommended in hemodinamically unstable patients, large thrombus or recurrent embolic episodes. These high-risk conditions are often not the case. Therefore, in many patients the surgical risk is much greater than that of bleeding associated with thrombolytic administration. Ultra-slow infusions have been reported with similar efficacy and lower rates of bleeding complications. We present a case of mitral prosthetic valve thrombosis considered not feasible to surgical management and subsequently treated with an ultra-slow tissue plasminogen activator infusion.

Clinical outcomes of patients with mitral prosthetic valve obstructive thrombosis treated with streptokinase or tenecteplase

Agent of choice for thrombolytic therapy (TT) in prosthetic valve thrombosis (PVT) is unknown. 84 mitral obstructive-PVT episodes treated with TT (43: Tenecteplase; 41: Streptokinase) were included in this prospective study. The incidence of primary end-point (CCS: complete clinical success, defined as complete or partial hemodynamic success with no complications or surgery) was 84.5% with recurrent PVT as a sole predictor. Bleeding and embolic manifestations were noted in 8.3% and 4.7% of episodes respectively. Tenecteplase use was associated with lower complication rate and a mitral EOA of <0.74 cm² at presentation predicts the need for extended thrombolysis (accuracy, 78.6%).

Successful Fibrinolytic Therapy in a Challenging Obstructive Prosthetic Mitral Valve Thrombosis

Prosthetic valve thrombosis is a rare and severe complication of the mechanical prosthetic valve. Management can be challenging due to varying clinical presentation, overlapping features of differential diagnosis, and lack of randomized controlled trials on the therapeutic options. In this article, we report the case of a patient with a mechanical prosthetic mitral valve presented with symptoms of heart failure, and an echocardiography showing increased mean pressure gradient across the prosthesis along with a fixed posterior leaflet and a partially restricted anterior leaflet with no visible mass. That raised the concern for an obstructed prosthesis. After multimodality imaging and multidisciplinary team discussions, prosthetic valve thrombosis diagnosis was favored over other different diagnoses that included but not limited to pannus ingrowth. Fibrinolytic therapy was administrated, and the patient was discharged on optimal anticoagulation. Repeated echocardiography a month later showed normal mean gradient and normal functioning prosthetic mitral valve without the need for repeat mitral valve surgery.

Case report of successful low-dose, ultra-slow infusion thrombolysis of prosthetic mitral valve thrombosis in a high risk patient after redo-mitral valve replacement

Background

An increase in transvalvular pressure gradient of prosthetic valve should always raise suspicion for obstructive valve thrombosis. A multimodality diagnostic approach including transthoracic echocardiography, transoesophageal echocardiography (TOE), cinefluoroscopy, or computed tomography (CT) is necessary for a prompt diagnosis. The management of mechanical prosthetic valve thrombosis (PVT) is high risk in any therapeutic option taken. Emergency valve replacement is recommended for critically ill patients. Fibrinolysis is an alternative for patients with contraindication to surgery or if surgery is not immediately available.

Case summary

A 52-year-old woman presented with symptoms and signs of cardiac congestion. On laboratory, brain natriuretic peptide was elevated and international normalized ratio (INR) was in subtherapeutic range. She underwent a mitral valve replacement with mechanical prosthesis 7 months before, because of a significant residual regurgitation after repair on the same year. TOE revealed severe stenosis of the prosthesis with immobile anterior disc but there was no mass present. CT revealed a minor lesion at the hinge points of the prosthesis without involvement of the ring, suggestive for thrombus. The initial fruitless management with intravenous (i.v) heparin in high therapeutic range was followed by a successful 'low-dose, ultra-slow' fibrinolysis.

Discussion

CT may help differentiate thrombus vs. pannus. The acute onset of symptoms, inadequate anticoagulation, and restricted leaflet motion increased the suspicion for PVT. The current European guidelines propose normal dose fibrinolysis. We performed 'low-dose, ultra-slow' fibrinolysis due to lower bleeding risk with successful results. Low dose should be considered as alternative to normal dose fibrinolysis or urgent surgery.

A 70-Year-Old Woman With a Prosthetic Mitral Valve and Sudden Chest Pain

CASE PRESENTATION

A 70-year-old woman presented to the ED with oppressive ongoing chest pain that had lasted for 1 hour and was accompanied by intense sweating. The patient had a previous history of bronchial asthma, severe degenerative mitral regurgitation, and an ostium secundum atrial septal defect that had been treated 6 years ago with a prosthetic mechanical mitral valve, Bicarbon 25, and an atrial septal defect closure. She was being treated with ciclesonide, tiotropium bromide, olodaterol, theophylline, and warfarin, adjusted according to the international normalized ratio. Two weeks before the current event, because of trauma suffered in her leg, her primary care physician changed her treatment to subcutaneous enoxaparin, 80 mg once daily. Considering that her weight was 80 kg and her renal function was normal, the dose of enoxaparin prescribed was subtherapeutic for a mechanical prosthetic valve.

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.

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.

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.

Thrombolytic treatment for acute prosthetic valve thrombosis: Is it better than surgery?

Prosthetic valve thrombosis (PVT) is a rare but often lethal complication of valve replacement. Despite advances in surgical techniques, surgical mortality remains high and emergent cardiac surgery is not widely available. Herein, we present the case of an acute PVT successfully treated with thrombolytic therapy. A 48-year-old female presented to the emergency department with acute onset of shortness of breath. Her medical history was remarkable for mitral valve replacement at the age of 42 years. Her symptoms began 4 h before, when she suddenly presented severe resting dyspnea. At arrival she showed pulmonary edema and hemodynamic instability. Echocardiography showed a prosthetic mitral valve stuck in a semi-closed position with a gradient of 39 mm Hg. Treatment was started with alteplase and the patient presented marked clinical improvement in subsequent hours. Recent evidence suggests that thrombolysis could be elected as the first choice of treatment in patients with left-side PVT because of the effectiveness, safety profile, availability, and low cost. This case illustrates the importance of prompt diagnosis and treatment and proposes thrombolytic therapy for PVT as an option at least as efficient as and far more accessible than surgery. <Learning objective: This case illustrates the importance of prompt diagnosis of prosthetic valve thrombosis (PVT) and proposes thrombolytic therapy for PVT as an option at least as efficient as and far more accessible than surgery.>.

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.

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.