Thrombolytic therapy for prosthetic valve thrombosis: short- and long-term results

A Challenging Case of Mechanical Mitral Valve Obstruction

Prosthetic valve thrombosis (PVT) is a frequent complication with a mechanical valve that presents with symptoms of heart failure or thromboembolic episodes. A 45-year-old lady with antiphospholipid syndrome (APS) complicated by a previous history of native mitral valve thrombus and mechanical mitral valve replacement maintained on warfarin presented with complaints of chest pain and shortness of breath (NYHA class 2). The initial lab showed a subtherapeutic international normalized ratio (INR) of 1.8. Transthoracic echo (TTE) showed severe mitral stenosis with a normal ejection fraction of 65%, elevated peak gradient of 34.5 mmHg, mean gradient of 23.7 mmHg, and pressure half time of 214 ms. Cine-fluoroscopic images revealed an immobile posterior mitral valve leaflet. She failed two trials of low-dose alteplase therapy during the hospitalization. Hence cardiac CT with contrast was done, which showed a small degree of pannus formation on the ventricular surface of the mitral valve ring and a small thrombus. Due to persistent immobility of the post mitral valve after two doses of alteplase and a cardiac CT scan concerning pannus formation, a multi-departmental decision was made to proceed with mechanical mitral valve replacement, following which she had a good recovery. Our case report depicts the importance of imaging study, like cardiac CT scan that can help distinguish thrombus (which has a lower Hounsfield unit, HU of <90) vs. pannus (higher HU of more than 145).

Development and validation of a mobile application based on a machine learning model to aid in predicting dosage of vitamin K antagonists among Indian patients post mechanical heart valve replacement

Patients who undergo heart valve replacements with mechanical valves need to take Vitamin K Antagonists (VKA) drugs (Warfarin, Nicoumalone) which has got a very narrow therapeutic range and needs very close monitoring using PT-INR. Accessibility to physicians to titrate drugs doses is a major problem in low-middle income countries (LMIC) like India. Our work was aimed at predicting the maintenance dosage of these drugs, using the de-identified medical data collected from patients attending an INR Clinic in South India. We used artificial intelligence (AI) - machine learning to develop the algorithm. A Support Vector Machine (SVM) regression model was built to predict the maintenance dosage of warfarin, who have stable INR values between 2.0 and 4.0. We developed a simple user friendly android mobile application for patients to use the algorithm to predict the doses. The algorithm generated drug doses in 1100 patients were compared to cardiologist prescribed doses and found to have an excellent correlation.

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.

Mechanical prosthetic valve thrombosis in current era: 5-year follow-up

Introduction

The incidence of prosthetic valve dysfunction (stuck valve) is variable and is dependent on various factors. There are studies from Indian groups that have emphasized the success of thrombolysis; however, none of them reported a follow-up. This study was designed to emphasize on the follow-up of these patients at midterm.

Material and methods

The patients of prosthetic valve thrombosis between period of January 2013 and December 2017 were included in this retrospective observational study. Sixty-six patients were admitted with stuck valve during this period. Thrombolysis was preferred modality of treatment. Survivors were followed up with serial echocardiography, which included estimation of left ventricular and valve functions.

Results

Of a total of 66 patients, 59 were of stuck mitral valve and 7 stuck aortic valve. The event happened at a mean of 48.86 ± 48.80 months after index operation of valve replacement using mechanical valve prosthesis. The median age was 40.27 ± 10.8 years with 39 males and 27 females. Thrombolysis was successful in 61 patients with a mortality of 5 (7.57%). During a mean follow-up of 22.7 ± 20.9 months, 42 patients were alive with 14 (22.95%) patients dead and 5 patients lost to follow-up. The average follow-up was 18.7 ± 22.7 months before death.

Conclusion

Following good early results after thrombolysis, patients of prosthetic heart valve thrombosis experience high mortality within 2 years of follow-up. These patients require frequent follow-up to avoid early mortality.

Ibutilide with magnesium for conversion of atrial fibrillation or flutter in rheumatic heart disease patients: Ibutilide with magnesium for chemical cardioversion of atrial fibrillation or flutter

Background

Data on adjunctive use of magnesium with ibutilide for conversion of persistent rheumatic atrial fibrillation and flutter to sinus rhythm is lacking.

Aim

We aimed to study the efficacy of adjunctive supplementation of intravenous magnesium with ibutilide for conversion of persistent rheumatic atrial fibrillation and flutter to sinus rhythm and to define a definite level of serum magnesium which leads to significant increase in rates of such conversion.

Methods and results

This was a prospective study including 33 Rheumatic heart disease patients (13 males and 20 females) with mean age of 49.27 ± 11.4 years and persistent AF or AFl. All patients received intravenous magnesium to raise serum magnesium level in range of 4 mg/dl to 4.5 mg/dl prior to administration of Ibutilide. 25 out of 33 (76%) patients converted to sinus rhythm. Upon univariate analysis, presence of background beta blocker therapy, serum potassium and magnesium at time of Ibutilide injection were found to have significant relation with conversion to sinus rhythm. Upon multivariate analysis serum magnesium level at the time of Ibutilide injection was found to have significant contribution on post injection rhythm reversal (p-value = 0.006).

The level of magnesium at 3.8 mg/dl was found to have maximum sensitivity of 96% and specificity of 62.5% for conversion to sinus rhythm by ibutilide with magnesium (p-value< 0.05).

Conclusions

Ibutilide is highly effective in cardioversion of persistent rheumatic atrial fibrillation/flutter patients. Raising Serum Magnesium levels above 3.8 mg/dl significantly improves efficacy of ibutilide.

Clinical Outcomes of Mechanical Prosthetic Valve Thrombosis

Objective

To evaluate characteristics and outcomes of patients presenting with mechanical prosthetic valve thrombosis in a tertiary cardiac center in Pakistan.

Methods

This was a prospective and interventional study conducted at Rawalpindi Institute of Cardiology over a period of two years. The clinical characteristics of patients presenting with clinical suspicion of prosthetic valve thrombosis were recorded. They were, then, subjected to streptokinase, redo surgery and heparin based on their hemodynamic stability, thrombus burden and surgical risk. The patients were then followed for the outcomes of the study.

Results

Out of 576 patients with mechanical valve replacement during the study period, 70 patients had developed prosthetic valve thrombosis. Out of 70 patients, there were 41 female (58.50%) and 29 male (41.50%) participants. The mean age of the participants was 48.40±15.00 years. The overall incidence of mechanical prosthetic valve thrombosis was 12.15%. There were 30 patients (42.80%) with a suboptimal international normalized ratio (INR) and 28 patients (40.00%) were non-compliant to warfarin therapy. The overall incidence of adverse clinical outcome was 18.00%, while the overall mortality rate was 10.00%. The mortality was higher for patients who underwent redo surgery (16.60%) as compared to patients who had received fibrinolytic therapy (9.60%).

Conclusion

Poor compliance with warfarin and suboptimal INR are the important factors causing mechanical prosthetic valve. Because of lower mortality rate, fibrinolysis with streptokinase is a reasonable treatment option for mechanical prosthetic valve thrombosis.

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.

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.

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.

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.

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.

Prosthetic heart valve thrombosis treated with low-dose slow-infusion fibrinolytic therapy

Thromboembolic complications following heart valve replacements are rare but a severe situation. Cerebral infarcts, transient neurologic deficits, and cardiac arrest due to stuck prostheses are among possible critical outcomes. Diagnosis and appropriate treatment should be initiated rapidly. Echocardiography plays a significant role in diagnosis. Fibrinolysis, anticoagulation with heparin, and surgical intervention are considered among the treatment modalities. Medical treatment is conducted according to the valvular condition and the clinical status of the patient. In order to prevent probable complications and enhance the efficiency of fibrinolysis, different approaches have been established regarding the dose and rate of the medication. In the present case, we report a prosthetic heart valve thrombosis successfully treated with an administration of low-dose, slow-infusion fibrinolytic agent. <Learning objective: Valvular thrombotic complications after heart valve replacement operations are associated with high morbidity and mortality. Efficient and urgent treatment is necessary. Considering the medical treatment, popular conviction about fibrinolytic therapy has depended on the principal of 'the more, the better' to date. However, complications of the fibrinolysis may aggravate hemorrhagic complications with high doses. In this case report, we aimed to state that low-dose slow-infusion thrombolysis is as efficient as higher doses with fewer complications.>.

Antistreptokinase antibodies and outcome of fibrinolytic therapy with streptokinase for left-sided prosthetic valve thrombosis

BACKGROUND

Left-sided prosthetic valve thrombosis (PVT) is a serious complication of valve replacement. In developing countries, fibrinolysis with streptokinase (SK) is often used as the first line of treatment. Anti-streptokinase (anti-SK) antibodies are widely prevalent in the general population, but their effect on the efficacy and outcome of fibrinolysis with SK in patients with PVT is not known.

METHODS

Patients with rheumatic heart disease and prosthetic valve replacement presenting with a first episode of left-sided PVT were enrolled. All patients underwent fibrinolysis with SK. An indirect enzyme-linked immunosorbent assay was used to detect anti-SK antibodies before fibrinolysis. Relationship of these antibodies to the outcome of fibrinolysis was evaluated.

RESULTS

Forty-four patients treated for left-sided PVT were included. Thrombosis affected 33 mitral and 11 aortic prosthetic valves. On fibrinolysis with SK, 32 (73%) patients achieved complete success, whereas it was unsuccessful in the remaining 12 patients. There were 3 bleeding events, 1 stroke, and 3 deaths. Mean anti-SK antibody levels were not significantly different between patients who had complete success and those who did not (8.81 ± 2.43 vs 7.67 ± 1.26 Au/mL; P = .13) and did not correlate with the outcome after adjustment with other variables. Patients in New York Heart Association class III or IV had a greater chance of failed fibrinolytic therapy, even after adjustment for other prognostic variables (odds ratio 9.0; 95% CI 1.29-63.02; P = .027).

CONCLUSION

Anti-SK antibody titers are not associated with success of fibrinolytic therapy using SK in patients with left-sided PVT.

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.

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.

Successful thrombolytic treatment of prosthetic mitral valve thrombosis

Prosthetic heart valve thrombosis is a rare but serious complication. Surgery is the first-line therapy in symptomatic obstructive mechanical valve thrombosis, thrombolytic therapy has been used as an alternative to surgical treatment. In this case report we described a 47-year-old woman who had undergone coronary artery bypass graft and mitral valve replacement operation 9 months ago. A thrombus was detected on the prosthetic mitral valve with high transmitral gradient by transoesophageal echocardiography. Tissue plasminogen activator treatment was administered successfully. The gradient was improved on prosthetic mitral valve and embolic complications or bleeding were not occurred.

Antithrombotic therapies in patients with prosthetic heart valves: guidelines translated for the clinician

Patients with prosthetic heart valves require chronic oral anticoagulation. In this clinical scenario, physicians must be mindful of the thromboembolic and bleeding risks related to chronic anticoagulant therapy. Currently, only vitamin K antagonists are approved for this indication. This paper reviews the main heart valve guidelines focusing on the use of oral anticoagulation in these patients.

Comparison of Fibrinolytic versus Surgical Therapy in the Treatment of Obstructive Prosthetic Valve Thrombosis: A Single-Center Experience

Objective: Prosthetic heart valve thrombosis (PVT) is a rare but severe cardiac condition. There are only a few data regarding comparison of the fibrinolytic and surgical approaches for the treatment of PVT. In this study, we compared the results of fibrinolytic therapy versus surgery in patients who presented to our institution with a diagnosis of obstructive-type PVT.Methods: From January 2001 to August 2008 in our institution, 33 patients who met clinical and echocardiographic criteria for obstructive-type PVT were included in the study. Fifteen of these patients underwent fibrinolytic treatment with streptokinase, which consisted of an initial bolus of 250,000 U followed by 100,000 U/h. Eighteen patients were treated with surgery.Results: The 2 groups had similar baseline characteristics, including New York Heart Association functional status, types and positions of prosthetic valves, international normalized ratio values, and presentation symptoms. Full hemodynamic success was achieved in 12 patients who underwent fibrinolytic therapy and in 15 patients in the surgery group. The mean (SD) streptokinase infusion time was 17.8 11.1 hours. Two major hemorrhages and 2 cases of systemic embolism were observed in the fibrinolytic group. The 2 groups did not differ with respect to mortality rate (P = .79). The duration of hospitalization was longer in the fibrinolytic group than in the surgery group (10.7 6.6 days versus 6.9 6.7 days, P = .045).Conclusions: Although fibrinolytic therapy is generally recommended for the treatment of PVT for specific patient groups, our results suggest that it may be as efficacious and safe as surgery, depending on patient selection.

Thrombolytic therapy in the treatment of right-sided prosthetic valve thrombosis in adults with congenital heart disease

Valve thrombosis is a potentially dangerous complication for right sided prosthetic valves in adults with congenital heart disease. Thrombolytic therapy is an important alternative to surgery and may be of benefit in patients with a history of multiple surgical interventions. We present two cases of successful thrombolytic therapy for right sided valve thrombosis in patients with congenital heart disease.

Comparison of thrombolysis versus surgery as a first line therapy for prosthetic heart valve thrombosis

Prosthetic valve thrombosis (PVT) is one of the most serious long-term complications after heart valve replacement, and optimal treatment remains unclear. The investigators report clinical characteristics and outcome of all consecutive patients with PVT treated with urgent surgery or thrombolysis with recombinant tissue plasminogen activator at a single center from January 1988 to December 2008. Thirty-one patients (mean age 59 years, range 20 to 75, 19% men) were diagnosed with PVT a median of 11 years after valve replacement (range 4 months to 32 years). Affected valve positions were mitral in 17 (55%), aortic in 8 (26%), and tricuspid in 6 (19%), and all but 1 were mechanical valves. Eighteen patients underwent urgent surgery, with 2 deaths in the immediate perioperative phase and 2 recurrences (11%) of PVT over a median follow-up period of 76 months. Of 13 patients treated with thrombolysis, there was immediate clinical improvement after a single administration of recombinant tissue plasminogen activator in 12 (92%), of whom 8 (61%) showed complete response with normalization of echocardiographic findings. The only nonresponder was subsequently referred for urgent surgery. Over a median follow-up period of 18 months, recurrence of PVT was seen in 4 patients (31%), with 1 fatal event in a patient refusing further anticoagulation treatment 1 week after successful thrombolysis. Other complications in the recombinant tissue plasminogen activator group included 1 stroke, 1 transient ischemic attack, 1 hemorrhagic complication requiring surgery, and 2 peripheral embolic events with spontaneous resolution. In conclusion, thrombolysis is an attractive first-line therapy for patients with PVT, with clinical outcomes comparing favorably with the standard surgical approach.

Treatment of Mechanical Aortic Valve Thrombosis Fibrinolytic Treatment versus Surgical Intervention: Result of Eight Cases

Objective

Thrombosis of mechanical heart valve prosthesis is a rare fatal complication after heart valve replacement. Although surgical intervention is the suggested treatment in many series, fibrinolytic treatment offers a good alternative. We describe eight cases with mechanical aortic valve thrombosis and compare their results after fibrinolytic treatment or redo aortic valve replacement.

Methods

Between February 2008 and March 2009, eight patients with previous mechanical prosthetic aortic valve replacement history were admitted to our center with mechanical aortic valve thrombosis. Four patients were operated, and the remaining four patients received low-dose fibrinolytic treatment. All patients’ data were collected prospectively.

Results

Two of the four operated patients died. In the fibrinolytic group, all patients totally recovered, and there was no mortality or morbidity during the follow-up period.

Conclusions

We thought that fibrinolytic treatment is a feasible and effective method for thrombosed mechanical aortic valve. However, much more populated patient groups are needed for the vigorous inference.

Complete thrombus resolution with tirofiban in obstructive mechanical prosthetic mitral valve thrombosis

Mechanical prosthetic valve thrombosis is a rare but life threatening complication after valve replacement. Although the traditional treatment of prosthetic valve thrombosis is surgery, recently thrombolytic therapy has been accepted as an alternative treatment. We describe for the first time prosthetic valve obstructive thrombus that was resolved by administering tirofiban (glycoprotein IIb/IIIa receptor antagonist) in a patient using warfarin with an international normalized ratio of 3.4. In our view, although this issue need to be clarified in further studies, tirofiban seems to be an alternative therapy especially in patients who have high risk of bleeding or surgical complication.

Intermittent, noncyclic dysfunction of a mechanical aortic prosthesis by pannus formation

Mechanical aortic prosthesis dysfunction can result from thrombosis or pannus formation. Pannus formation usually restricts systolic excursion of the occluding disk, resulting in progressive stenosis of the aortic prosthesis. Intermittent dysfunction of a mechanical aortic prosthesis is usually ascribed to thrombus formation. We describe an unusual case of intermittent, noncyclic dysfunction of a mechanical aortic prosthesis due to pannus formation in the absence of systolic restriction of disk excursion that presented with intermittent massive aortic regurgitation, severe ischemia, and shock. Pannus formation should be considered as a potential cause of acute intermittent severe aortic regurgitation in a patient with a mechanical aortic prosthesis.

Antithrombotic management of patients with prosthetic heart valves: current evidence and future trends

Over 4 million people worldwide have received a prosthetic heart valve, and an estimated 300,000 valves are being implanted every year. Prosthetic heart valves improve quality of life and survival of patients with severe valvular heart disease, but the need for antithrombotic therapy to prevent thrombotic complications in valve recipients poses challenges for clinicians and patients. Here, we review antithrombotic therapies for patients with prosthetic heart valves and management of thromboembolic complications. Advances in antithrombotic therapy and valve technologies are likely to improve the management of patients with prosthetic heart valves in developed countries, but the most important unmet need and potential for benefit from these new therapies is in developing countries where a massive and rapidly increasing burden of valvular heart disease exists.

O uso da estreptoquinase no tratamento da oclusão arterial aguda pós-cateterização da artéria femoral em crianças com menos de 10 kg

CONTEXTO: O tratamento da oclusão arterial aguda em menores de 5 kg tem constituído tema de discussão. OBJETIVOS: Avaliar o tratamento do quadro da oclusão arterial aguda pós-cateterismo da artéria femoral em crianças com menos de 10 kg com o uso de heparina isolada e também associada com estreptoquinase, e comparar os resultados do exame físico (como diagnóstico), da reversão da oclusão arterial, de complicações e de exames laboratoriais nos dois métodos MÉTODOS: Trinta casos de oclusão da artéria femoral foram identificados em 1.583 cateterismos em crianças no Instituto de Cardiologia de Porto Alegre, entre 1992 e 2000. Os pacientes foram divididos em dois grupos: um usou apenas heparina (14 casos), e o outro usou heparina associada com estreptoquinase (16 casos). Os exames laboratoriais (tempo de protrombina, tempo de tromboplastina parcial ativado e fibrinogênio) coletados antes e durante a infusão intravenosa foram avaliados estatisticamente, assim como o tempo de uso da medicação, as complicações e os resultados. RESULTADOS: O exame físico mostrou-se método fidedigno para avaliar a oclusão; no grupo que utilizou a associação de heparina e estreptoquinase, houve a resolução de 87% dos casos de oclusão arterial, e a principal complicação foi sangramento no sítio de punção em 56,3% dos pacientes. Os resultados apresentaram p < 0,05. Os exames laboratoriais não tiveram significado estatístico. CONCLUSÃO: A estreptoquinase associada com a heparina é mais efetiva do que a heparina isolada no tratamento da oclusão arterial aguda da artéria femoral pós-cateterismo, tanto que sua associação apresenta uma redução do risco relativo de 88% em relação à heparina isolada.

Thrombolytic Therapy for Acute Left Atrial Thrombus Formation in One Patient With Heart Failure and Atrial Fibrillation

Patients with a left atrial (LA) thrombus are considered at high risk of thromboembolic events. Reports about thrombolytic therapy are limited and optimal guidelines are lacking. In this report, a large, pedunculated, highly mobile thrombus of the LA attached via a short stalk to the LA appendage brim in a 59-year-old female with atrial fibrillation is described. The patient was treated with 100 mg intravenous tissue plasminogen activator for 2 h after the ineffective administration of herapin. The thrombus soon dissolved. However, the patient developed a transient ischemic embolism 12 h later when the post hoc heparin effect was at its nadir. Based on this and other reports, thrombolytic therapy may be effective and safe in patients with acute, non-organized LA thrombi and post hoc heparinization should be sufficient to prevent thromboembolism from rebound coagulation.