Transesophageal echocardiography for the diagnosis and management of nonobstructive thrombosis of mechanical mitral valve prosthesis

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.

Role of Imaging for Suspected Cardiac Thrombus

PURPOSE OF REVIEW

Cardiac thrombus formation is a frequent complication of a variety of prevalent diseases. Embolism of cardiac thrombus has the potential to result in significant morbidity and mortality from cerebrovascular and peripheral vascular events.

RECENT FINDINGS

Echocardiography is the most commonly used imaging modality for diagnosing intracardiac thrombus. However, technological advances in computed tomography and magnetic resonance imaging have allowed newer noninvasive modalities to evolve into robust tools for the clinical evaluation of patients suspected of disease. Complimentary use of these imaging techniques is crucial in the diagnosis of cardiac thrombus and initiation of anticoagulation therapy.

Prosthetic Valve Thrombosis in the Acute Phase of the Stroke: Relevance of Detection and Follow-Up

BACKGROUND

Stroke may be the first symptom of prosthetic valve thrombosis (PVT); therefore, rapid diagnosis and therapy are crucial. We aimed to evaluate the prevalence, main predictors, and long-term clinical evolution of patients with PVT in the acute phase of stroke.

METHODS

We studied consecutive acute ischemic stroke patients with prosthetic heart valves who underwent emergent transesophageal echocardiography (TEE) during a 5-year period. Two groups were defined depending on the presence of PVT (PVT or non-PVT groups). Baseline characteristics, TEE findings, and international normalized ratios (INRs) at the stroke event were registered. Follow-up visits and TEE control examinations were performed.

RESULTS

Sixty-seven patients were registered. TEE was performed within the first week in 85% of patients (n = 57). PVT was diagnosed in 41.8% of cases (n = 28). Clinical severity and baseline INR level showed no differences when the PVT and non-PVT groups were compared. The presence of PVT was associated with the mitral valve location as compared with the aortic valve location (75% versus 25%, P = .003), the presence of spontaneous echocontrast (64.3% versus 35.9%, P = .022), and low ejection fraction (66.7% versus 32.7%, P = .019). The PVT group showed a trend toward higher percentage of recurrence (10.7% versus 2.5%, P = .102) in the follow up period (mean follow-up 25 months).

CONCLUSIONS

The detection of PVT in the acute stroke phase was relevant, as the stroke recurrence rate was considerable. Therefore, all patients with prosthetic heart valve should undergo emergent TEE.

The Evolving Role and Use of Echocardiography in the Evaluation of Cardiac Source of Embolism

This report will review the role of echocardiography in the diagnosis of cardiac sources of embolism. Embolism of cardiac origin accounts for around 15%–30% of ischemic strokes. The diagnosis of a cardioembolic source of stroke is frequently uncertain and relies on the identification of a potential cardiac source of embolism in the absence of significant autochthonous cerebrovascular occlusive disease. Transthoracic and/or transesophageal echocardiography serves as a cornerstone in the evaluation, diagnosis, and management of these patients. This article reviews potential cardiac sources of embolism and discusses the role of echocardiography in clinical practice. Recommendations for the use of echocardiography in the diagnosis of cardiac sources of embolism are given including major and minor conditions associated with the risk of embolism.

Guidelines for the Use of Echocardiography in the Evaluation of a Cardiac Source of Embolism

Embolism from the heart or the thoracic aorta often leads to clinically significant morbidity and mortality due to transient ischemic attack, stroke or occlusion of peripheral arteries. Transthoracic and transesophageal echocardiography are the key diagnostic modalities for evaluation, diagnosis, and management of stroke, systemic and pulmonary embolism. This document provides comprehensive American Society of Echocardiography guidelines on the use of echocardiography for evaluation of cardiac sources of embolism. It describes general mechanisms of stroke and systemic embolism; the specific role of cardiac and aortic sources in stroke, and systemic and pulmonary embolism; the role of echocardiography in evaluation, diagnosis, and management of cardiac and aortic sources of emboli including the incremental value of contrast and 3D echocardiography; and a brief description of alternative imaging techniques and their role in the evaluation of cardiac sources of emboli. Specific guidelines are provided for each category of embolic sources including the left atrium and left atrial appendage, left ventricle, heart valves, cardiac tumors, and thoracic aorta. In addition, there are recommendation regarding pulmonary embolism, and embolism related to cardiovascular surgery and percutaneous procedures. The guidelines also include a dedicated section on cardiac sources of embolism in pediatric populations.

Dabigatran exhibits low intensity of left atrial spontaneous echo contrast in patients with nonvalvular atrial fibrillation as compared with warfarin

The presence of spontaneous echo contrast (SEC) in the left atrium has been reported to be an independent predictor of thromboembolic risk in patients with atrial fibrillation (AF). Dabigatran was associated with lower rates of stroke and systemic embolism as compared with warfarin when administered at a higher dose. Between July 2011 and October 2015, nonvalvular AF patients treated with warfarin or dabigatran who had transesophageal echocardiography prior to ablation therapy for AF were enrolled. The intensity of SEC was classified into four grades, from 0 to 3. Univariate and multivariate analysis was performed to analyze factors associated with SEC. Sixty-five patients were on dabigatran and 65 were on warfarin, with the prothrombin time in therapeutic range. There were no significant differences in the age, CHADS2 score, left atrial dimension, and left atrial appendage flow between the two groups. However, there were more grade 2 or higher patients with left atrial SEC in the warfarin group (n = 20) than in the dabigatran group (n = 2) (p < 0.001). When multivariate regression analysis was performed, grade 2 or higher left atrial SEC was independently associated with no dabigatran usage in addition to high brain natriuretic peptide level and high incidence of diabetes mellitus or persistent AF. Thus, dabigatran exhibited low intensity of left atrial SEC in nonvalvular AF patients as compared with warfarin.

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.

Treatment of Prosthetic Valve Thrombosis: Current Evidence and Future Directions

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

Transesophageal Echocardiographic Diagnosis of Acute Atrioventricular Valve Thrombosis in a Patient with a Single Ventricle Undergoing Implantation of a Ventricular Assist Device

Mechanical valve thrombosis is a severe complication of valve replacement associated with significant patient morbidity and mortality. The main factors that predispose patients to thrombus formation include endothelial injury or dysfunction, hypercoagulability, and hemodynamic changes. Other contributing factors include level of anticoagulation, tricuspid valve replacement, bacteremia, and certain patient comorbidities. Early diagnosis of thrombus could prevent adverse patient outcomes. We describe the use of transesophageal echocardiography in the diagnosis of acute thrombus in a patient with a recently replaced single atrioventricular valve.

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.

Sources of thromboembolism in patients with correctly functioning mechanical valves: a single-center transesophageal echocardiographic study

BACKGROUND

In patients with mechanical prostheses (MP), thromboembolism is one of the most serious complications. The study aim was to assess the incidence of sources of thromboembolism in patients with correctly functioning MP with and without a history of thromboembolism.

METHODS

Two hundred ninety-seven patients with correctly functioning MP were enrolled in this single-center, transesophageal echocardiographic (TEE), retrospective, observational study. Two groups were analyzed: Group A, 183 patients with a history of thromboembolism, and Group B, 114 patients with no history of thromboembolism.

RESULTS

Definite sources of thromboembolism were revealed in 59% of patients in Group A, and sources of potential thromboembolism were revealed in 13% of patients in Group B (P < .001). Multiple sources of thromboembolism were present in 9% of patients in Group A and 1% of patients in Group B. Localization of sources of thromboembolism included MP ring (59% and 53% of patients in Groups A and B, respectively); left atrium/left atrium appendage (24%/21% and 13%/40% of patients in Groups A and B, respectively); and aorta (12% and 13% of patients in Groups A and B, respectively). Patients with multiple sources of thromboembolism were older (P < .001) and in a higher New York Heart Association (NYHA) class (P = .004). Patients with sources of thromboembolism in the aorta were older than the rest of the group (P < .01).

CONCLUSIONS

In patients with correctly functioning MP, sources of thromboembolism are observed 4 times more often in case of the positive history of thromboembolism. The most common source of thromboembolism is thrombosis of MP ring. Age and heart failure predispose multiple sources of thromboembolism. One might consider control TEE after mechanical valve implantation, but only in selected group of patients without embolic events but with a higher risk of thromboembolism.

Choice of echocardiography method for postoperative evaluation of mitral valve replacement with a mechanical prosthesis

OBJECT

The French Cardiology Society (SFC) systematically recommends (Class I) transesophageal echocardiography (TEE) after any mitral valve replacement with a mechanical prosthesis (MMVR). Taking into account the increasing workload of echocardiography laboratories, our attitude was to propose that only post-operative transthoracic echocardiography (TTE) is performed. The purpose of this study was to evaluate the possible risks of this simplified procedure.

METHODS

We performed a precise analysis of one full year of practice of MMVR with exhaustive follow-up for the first 2 years concentrating on thromboembolic complications.

RESULTS

From January to December 2003, 84 MMVRs (46 after rheumatic fever, 22 degenerative disease, 11 infective endocarditis (IE) and 5 ischemia) were conducted in 45 women and 39 men of average age 61 years. Early mortality (<30 days) concerned 5 patients (5.9%). A control TTE to determine normal prosthetic function was performed 7+/-2 days after surgery and this revealed 2 cases of nonobstructive thrombosis which were treated medically, 3 cases of paraprosthetic regurgitation, and 1 vegetation due to underlying IE. Actuarial survival was 90.5% at 1 year and 83.3% at 2 years. After a mean follow-up of 179.3 patient-years, 5 patients were reoperated (5.9%): 1 for IE, 1 for paravalvular regurgitation, 1 for mitral valve insufficiency with haemolysis, and 2 for obstructive prosthetic valve thromboses. In addition there were 2 cases of prosthetic valve thrombosis, 8 ischemic strokes (2 ministrokes, 6 sequelar strokes), and 1 peripheral embolism. The global thromboembolic complication rate was therefore 6.1 per 100 patient-years (n=11). There were 4 hemorrhagic events, i.e. a rate of 2.2 events per 100 patient-years. 63% of the 1193 INR conducted were within the target range (3-4.5), 26% were below 3 and 11% were greater than 4.5. 35% of patients with thromboembolic complications had an INR<3.

CONCLUSION

Morbidity and mortality during the first 2 years after MMVR were relatively high but equivalent to the values of comparable series in the literature. These complications would not have been reduced by a more precise screening based on early TEE. Despite the increasingly litigious nature of the doctor-patient relationship, it would probably be excessive to oppose that this guideline was not followed in a dispute; in particular as it is difficult to apply this measure as echocardiography departments are overworked.

Surgical management of mechanical valve thrombosis: twenty-six years' experience

In the present study, the authors investigated the management of mechanical valve thrombosis (MVT). From January 1981 through March 2006, 2,908 mechanical valve replacements were performed in 2,298 patients at our institution. Twenty (0.87%) patients presented with MVT, 14 (70.0%) were women, and the mean age of the patients was 42.0+/-14.0 (27-66) yr. Thrombosis involved mitral in 14 (70.0%), aortic in 2 (10.0%), tricuspid/aortic in 1 (5%), and tricuspid in 3 (15%). The interval from first operation to valve thrombosis was 121.8+/-75.4 (0.9-284.7) months. The most frequent clinical presentation was heart failure (13/20, 65%), and predisposing causes of MVT were: poor compliance with warfarin (7), pregnancy (5), drug interaction (2), and unknown (6). All 20 patients underwent valve replacement: mitral (14, 70.0%), tricuspid (3, 15.0%), aortic (2, 10%) and tricuspid/aortic (1, 5%). One early death occurred due to left ventricular failure, but no late mortality occurred during 63.3+/-49.9 (0.5-165.1) months of follow-up. MVT was treated successfully, and pregnancy and inadequate anticoagulation were found to influence the occurrence of this rare complication.

Evaluation of hypoxemic patients with transesophageal echocardiography

OBJECTIVE

To summarize the use of transesophageal echocardiography when investigating hypoxemic patients in the intensive care unit, to assess its risks and benefits, and to evaluate which diseases of the cardiopulmonary system, mediastinum, and thorax it will help to guide therapeutic decisions.

DESIGN

A review of current literature and practice guidelines was performed.

RESULTS

Hypoxemia, due to a number of different reasons, is common in critically ill patients. Many diagnoses and therapeutic decisions have to rely on good-quality imaging. However, transthoracic echocardiography often produces poor-quality pictures; other imaging modalities involve transferring unstable patients to the imaging suite. Transesophageal echocardiography can safely be performed at the bedside and generates excellent image quality.

CONCLUSION

Transesophageal echocardiography is a safe procedure that can be performed at the bedside and that produces high-quality images of the heart, its related structures, and its function. It helps detect extracardiac pathology leading to hypoxemia and may be used to guide fluid resuscitation and optimize tissue oxygenation.

Feasibility and diagnostic accuracy of quantitative assessment of mechanical prostheses leaflet motion by transthoracic and transesophageal echocardiography in suspected prosthetic valve dysfunction

Transthoracic (TTE) and transesophageal echocardiography (TEE) are the standard techniques for the evaluation of prosthetic valve function. However, quantitative evaluation of leaflet(s) motion is not routinally carried out, although leaflet(s) opening and closing angle measurements are important information to recognize prosthetic dysfunction. For this purpose, cinefluoroscopy is considered the "gold standard" technique. The aim of this study was the evaluate the diagnostic accuracy of TTE and TEE in the quantitative assessment of leaflet motion in patients with mechanical protheses. One hundred-eleven patients with mitral (single disk 18; bileaflet 48) and aortic (single disk 22; bileaflet 23) prostheses, were referred to TTE, TEE, and cinefluoroscopy for electrical cardioversion of atrial fibrillation (n = 40) or suspected prosthesis dysfunction (n = 71). Echocardiographic evaluation included leaflet(s) opening and closing angle measurements; results were compared with cinefluoroscopy. For mitral prostheses, opening and closing angles were correctly identified by TTE in 85% and by TEE in 100% of patients, regardless of prosthetic valve type, with a good concordance with cinefluoroscopy. For aortic prostheses, opening angles were correctly identified by TTE and TEE, respectively, in 40% and 77% of patients with single-disk and in 13% and 35% of patients with bileaflet prostheses. Both TTE and TEE were rarely able to identify closing angles. In conclusion, quantitative evaluation of mitral leaflet(s) motion may be accurately achieved with TTE and TEE, leading to increased diagnostic efficacy of prosthetic valve dysfunction. In the aortic position, TTE and TEE allow a quantitative evaluation of leaflet(s) dynamics only in a minority of patients and cinefluoroscopy still remains the first-choice technique.

Clinical significance of early thrombosis after prosthetic mitral valve replacement: a postoperative monocentric study of 680 patients

OBJECTIVES

The aim of this study was to evaluate the incidence of early thrombosis, its prognostic significance, and the therapeutic implications.

BACKGROUND

Transesophageal echocardiography (TEE) is the method of choice for detecting symptomless early postoperative thrombosis of prosthetic valves. However, the clinical significance is not yet known.

METHODS

Between June 1994 and December 2000, 680 consecutive patients underwent TEE on day 9 after mechanical mitral valve replacement, to search for early thrombosis. Initially, end points were the in-hospital outcome and treatment. Patients were also evaluated 34 +/- 22 months after surgery.

RESULTS

Sixty-four early thrombi were detected (9.4%). Two early obstructive were treated by redo-surgery. Sixty-two nonobstructive benefited from medical treatment. The patients were allocated into two groups as a function of the maximum size of thrombus: <5 mm in 29 patients (group A) and > or =5 mm in 35 (group B). During early follow-up, we observed one complicated course in group A and eight in group B. In the long-term survey, three complications were noted in group A and 11 in group B. Incidence of early (p = 0.027) and long-term (p = 0.04) complications were significantly different in the two subsets.

CONCLUSIONS

This study confirms the incidence of early thrombi after mechanical mitral valve replacement detected by TEE. A small (<5 mm) nonobstructive thrombus seems benign, and our experience argues in favor of medical treatment. Prognosis appears more serious for large thrombi. Medically aggressive therapy and further surgery should be considered in cases of obstructive thrombosis or large and mobile nonobstructive thrombosis.

Prosthetic valve thrombosis: twenty-year experience at the montreal heart institute

BACKGROUND

Prosthetic valve thrombosis is a life-threatening complication. We reviewed the incidence, risk factors, and treatment strategies of this rare complication.

METHODS

From February 1981 through January 2001, 5430 valve operations were performed in 4924 patients at the Montreal Heart Institute. Of this cohort, 39 patients presented with prosthetic valve thrombosis and had complete follow-up data obtained from our prospective valve clinic database.

RESULTS

In this series 82% of patients were women, and the mean age was 58 +/- 11 years. The underlying pathology involved the mitral valve in 75% of cases. Most prosthetic valve thromboses occurred with mechanical prostheses (95%). The time interval from first valve replacement to prosthetic valve thrombosis was 39 +/- 42 months. The most frequent clinical presentation was severe congestive heart failure (44%). On prosthetic valve thrombosis presentation, the international normalized ratio was less than 2.5 in 54%, with inadequate anticoagulation management in 26% and poor compliance in 26%. Eighty-two percent of patients underwent a surgical procedure, consisting of thrombectomy in 47%, mitral valve replacement in 47%, and aortic valve replacement in 6% of patients. The 30-day operative mortality and total in-hospital mortality after prosthetic valve thrombosis were 25% and 41%, respectively. The 10-year actuarial survival after prosthetic valve thrombosis was 46% +/- 10%.

CONCLUSION

Inadequate level of anticoagulation is the most important factor involved in the pathogenesis of prosthetic valve thrombosis. The overall mortality rate despite surgical treatment remains high. This study underscores the importance of meticulous surveillance of anticoagulation therapy in patients with prosthetic valves.

Transesophageal echocardiography improves risk assessment of thrombolysis of prosthetic valve thrombosis: results of the international PRO-TEE registry

OBJECTIVES

The goal of this study was to evaluate whether quantitation of thrombus burden with transesophageal echocardiography (TEE) can help risk-stratify patients undergoing thrombolysis of prosthetic valve thrombosis (PVT).

BACKGROUND

Thrombolytic therapy of PVT has an unpredictable risk of embolization and complications.

METHODS

An international registry of patients with suspected PVT undergoing two-dimensional/Doppler and TEE before thrombolysis was established. All TEE studies were reviewed and quantitated by a single observer blinded to all data.

RESULTS

From 1985 to 2001, 107 patients (71 females; age 24 to 86 years) from 14 centers (6 in the U.S.) were identified. The majority of cases involved the mitral valve (79 mitral, 13 aortic, and 15 tricuspid). Hemodynamic success rate was achieved in 85% and was similar across valves. Overall complications were observed in 17.8%, and death in 5.6%. Predictors of complications were: New York Heart Association (NYHA) functional class, presence of shock, sinus tachycardia, hypotension, previous history of stroke, thrombus extension beyond the valve ring, and thrombus area. Multivariate analysis demonstrated that two variables were independent predictors of complications: thrombus area by TEE (odds ratio [OR] 2.41 per 1 cm2 increment, 95% confidence interval [CI] 1.12 to 5.19) and prior history of stroke (OR 4.55, 95% CI 1.35 to 15.38). A thrombus area <0.8 cm2 identified patients at lower risk for complications from thrombolysis, irrespective of NYHA functional class.

CONCLUSIONS

In PVT, the thrombus size imaged with TEE is a significant independent predictor of outcome. Transesophageal echocardiography can identify low-risk groups for thrombolysis irrespective of symptom severity and is therefore recommended in the management of prosthetic valve thrombosis.

Sequential use of thrombolytic agents for thrombosed mitral valve prosthesis during pregnancy

Thrombolytic therapy has gained popularity as an alternative to surgery in the treatment of prosthetic heart valve thrombosis. We report on the sequential use of streptokinase followed by recombinant tissue type plasminogen activator (rt-PA) for the treatment of a thrombosed prosthetic mitral valve in a pregnant woman at 26 weeks of gestation. Although thrombolysis was unsuccessful, the patient carried till 34 weeks of gestation and delivered by cesarean section a live newborn with an uneventful postpartum course. Based on our case and on what has been previously described in the literature, thrombolytic therapy should be considered as an option in the management of hemodynamically unstable pregnant patients with prosthetic valve thrombosis. When a single agent proves insufficient, combination therapy should be considered as it might provide hemodynamic stability and improvement in cardiac function that would allow patients at a high surgical risk to carry their pregnancy to viability.

Cloth tears in asymptomatic survivors of aortic valve replacement with Starr-Edwards prostheses: detection by transesophageal echocardiography

Cloth-covered Starr-Edwards valves were withdrawn in the 1970s because of complications of cloth tear. Nevertheless, many patients are still alive with their prosthesis in place. We evaluated the ability of transesophageal echocardiography (TEE) to detect cloth tear in 9 asymptomatic patients operated on with a cloth-covered Starr-Edwards aortic valve at our institution. An echogenic mobile structure attached to the prosthesis, suggestive of a tear, was detected in 5 patients (55%). A tear was diagnosed in a sixth patient when TEE was repeated during follow-up because of neurologic symptoms. In all cases, transthoracic echocardiography failed to detect any abnormality. Two patients had symptoms develop and underwent reoperation; cloth tear was more extensive than suspected by TEE. Cloth tear is a frequent finding that can be detected by TEE in asymptomatic patients with cloth-covered Starr-Edwards aortic prosthesis. TEE is recommended in these patients and reoperation should be considered as soon as symptoms appear.

[Prosthetic valve thrombosis: which is the most appropriate initial therapy?]

INTRODUCTION AND OBJECTIVES

This study aims to investigate what is the best initial therapy for patients with obstructive prosthetic valve thrombosis.

METHODS

Data from 47 patients diagnosed with prosthetic valve thrombosis in two tertiary hospitals during an 8-years period were analyzed.

RESULTS

The involved prostheses were in mitral position in 34 cases (2 biological valves), in aortic position in 12, and in double mitral and aortic position in one. The thrombosis was not obstructive in 12 patients. In the remaining 35 patients, the prosthetic obstruction was treated by heparin (n = 2), thrombolysis (n = 19), or direct surgery (n = 14). There was no mortality in the thrombolytic group, although 6 patients needed surgery before discharge because of an abnormal prosthetic residual gradient (n = 5) or a persisting abnormal disc valve motion (n = 1). Five out of 14 patients of direct surgery died, 2 before the planned operation could be performed. Thus, mortality rate, in an intention to treat analysis, was very favourable to thrombolytic therapy (p = 0.008); and this, despite the higher index of clinical severity (on a scale from 0 to 4) was superior in this group of thrombolyzed patients: 3.3 0.6 vs. 2.1 0.9 in those who underwent surgery; p < 0.0001.

CONCLUSIONS

In terms of mortality rate, thrombolysis is a better alternative than direct surgery to fight against obstructive prosthetic valve thrombosis. Even if the result is suboptimal, it allows the performance of surgery in better clinical conditions and, thus, with minor risk.

[Mitral prosthesis thrombosis treated by fibrinolysis with accelerated administration of r-TPA]

We report the case of a 53-year-old patient with a mitral prosthesis hospitalized for heart failure. Diagnosis of mitral prosthetic thrombosis, led to a therapeutic disjunction between thrombolysis and surgery. Because of the high risk of surgical intervention, the patient was treated with r-TPA (accelerated infusion), showing immediate, successful response.

Thrombolytic therapy of a left-sided prosthetic valve thrombosis without hemodynamic obstruction: a case report

We report a case of a 38-year-old woman with a prosthetic mitral valve who presented with multiple embolic events. Transesophageal echocardiography was used to diagnose nonobstructive thrombi on the prosthetic valve. She underwent successful thrombolytic therapy. The patient was discovered to be in a hypercoagulable state, which probably was caused by the concomitant use of phenytoin. We review the literature for diagnosis and treatment of nonobstructive prosthetic valve thrombosis.

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

BACKGROUND

Thrombolytic therapy (TT) has evolved as an alternative to surgery for prosthetic valve thrombosis (PVT), but its utility in patient management is still debated and the long-term results are not available.

METHODS

From 1990 through 1999, we treated 110 consecutive patients (52 men, mean age 35.4 +/- 10.8 years) of left-sided obstructive PVT (96 mitral, 14 aortic) with TT (streptokinase in 108, urokinase in 2) according to a specified protocol of prolonged infusion. Serial echo Doppler parameters were monitored in all patients to guide the duration of TT and to quantify its efficacy. Ninety of the 102 survivors of the index episode were followed up for a mean period of 31.3 +/- 27.8 months (range 1-112 months).

RESULTS

Complete hemodynamic response (on cinefluoroscopy and echo Doppler criteria) was seen in 90 (81.8%) episodes, partial response in 11 (10%), and failure in 9 (8.2%). The mean duration of TT was 42.8 +/- 20.4 hours. Five of the 7 patients who were initially seen in cardiogenic shock/overt pulmonary edema died during therapy. After these patients were excluded, the rate of complete response did not differ among patients with New York Heart Association class I/II (80%), class III (86.3%), or class IV (81.5%). The response rate also did not vary with the type, position of prosthesis, duration of symptoms, or time lag since surgery. There were 21 (19.1%) embolic episodes during therapy, including 6 strokes. These were significantly more frequent in patients with atrial fibrillation (AF) (odds ratio on multivariate analysis 2.3, 95% confidence interval 1.3-3.9, P =.01). On follow-up, there were 25 recurrences of PVT, of which 20 again received TT with a complete response in 14 (70%). At 5 years the actuarial survival was 85.2% and the event-free survival was 61.5%. The presence of chronic AF was a significant predictor of recurrence of PVT (odds ratio 2.2, 95% confidence interval 1.2-3.9, P =.008).

CONCLUSIONS

TT is effective in the majority of patients with PVT but is associated with a high rate of embolism, especially in patients with AF. Excluding patients with cardiogenic shock/overt pulmonary edema (in whom TT is largely ineffective), the success of TT does not vary with the New York Heart Association class, duration of symptoms, or other patient variables. The recurrence rates of PVT are high after even successful TT, especially in patients with AF.

Prediction of thrombus-related mechanical prosthetic valve dysfunction using transesophageal echocardiography

Identification of thrombus-related mechanical prosthetic valve dysfunction (MPVD) has important therapeutic implications. We sought to develop an algorithm, combining clinical and echocardiographic parameters, for prediction of thrombus-related MPVD in a series of 53 patients (24 men, age 52 +/- 16 years) who had intraoperative diagnosis of thrombus or pannus from 1992 to 1997. Clinical and echocardiographic parameters were analyzed to identify predictors of thrombus and pannus. Prevalence of thrombus and diagnostic yields relative to the number of predictors were determined. There were 22 patients with thrombus, 19 patients with pannus, and 12 patients with both. Forty-two of 53 masses were visualized using transesophageal echocardiography (TEE), including 29 of 34 thrombi or both thrombi and panni and 13 of 19 isolated panni. Predictors of thrombus or mixed presentation include mobile mass (p = 0.009), attachment to occluder (p = 0.02), elevated gradients (p = 0.04), and an international normalized ratio of < or = 2.5 (p = 0.03). All 34 patients with thrombus or mixed presentation had > or = 1 predictor. The prevalence of thrombus in the presence of < or = 1, 2, and > or = 3 predictors is 14%, 69%, and 91%, respectively. Thus, TEE is sensitive in the identification of abnormal mass in the setting of MPVD. An algorithm based on clinical and transesophageal echocardiographic predictors may be useful to estimate the likelihood of thrombus in the setting of MPVD. In the presence of > or = 3 predictors, the probability of thrombus is high.

Transesophageal echocardiographic (TEE) evaluation of prosthetic valves

TEE overcomes many of the imaging constraints associated with transthoracic echocardiography for the assessment of valvular anatomy and function. Additional imaging artifacts and constraints associated with prosthetic valves are minimized or overcome with TEE. As such, TEE allows assessment of prosthetic valve anatomy and function and paraprosthetic anatomy, and serves as the diagnostic imaging modality of choice for patients with suspected prosthesis dysfunction or endocarditis.

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

OBJECTIVE

We analyzed the results of intravenous thrombolytic treatment under transesophageal echocardiographic (TEE) guidance in prosthetic valve thrombosis.

BACKGROUND

Thrombotic occlusion of prosthetic valves continues to be an uncommon but serious complication. Intravenous thrombolytic treatment has been proposed as an alternative to surgical intervention.

METHODS

In a four-year period, 32 symptomatic patients with prosthetic valve related thrombosis underwent 54 thrombolytic treatment sessions for the treatment of 36 distinct episodes. All patients had low international normalized ratio values at the presentation. Transesophageal echocardiography was performed at baseline and repeated after each thrombolytic treatment session (total 98 TEE examinations). Streptokinase was used as the initial agent with a repeat dose given within 24 h when necessary. Recurrent thrombosis was treated either with tissue plasminogen activator or urokinase.

RESULTS

The initial success after first dose was only 53% (17/32) but increased up to 88% (28/32) after repeated thrombolytic sessions upon documentation of suboptimal results on TEE examination (p < 0.01). In addition, four asymptomatic patients with large thrombi were also successfully treated with single infusion. The TEE characteristics of thrombus correlated with clinical presentation and response to lytics. Success was achieved with single lytic infusion in 40% of the obstructive thrombi as compared with 75% of the nonobstructive ones (p < 0.05). The success rates of lytic treatment were similar for mitral versus aortic valves, and for tilting disk versus bileaflet valves. Rapid (3 h) and slow (15 to 24 h) infusion of streptokinase resulted in similar success rates. However, major complications (three patients) occurred only in the rapid infusion group.

CONCLUSION

In patients with prosthetic valve thrombosis, intravenous slow infusion thrombolysis given in discrete, successive sessions guided by serial TEE and transthoracic echocardiography can be achieved with a low risk of complications and a high rate of success.

Early and long-term (one-year) effects of the association of aspirin and oral anticoagulant on thrombi and morbidity after replacement of the mitral valve with the St. Jude medical prosthesis: a clinical and transesophageal echocardiographic study

OBJECTIVES

The aim of the study was to test the value of low dose aspirin associated with standard oral anticoagulants (OAC) after mechanical mitral valve replacement (MMRV) to reduce strands, thrombi and thromboembolic events.

BACKGROUND

Strands and thrombi are thought to increase the risk of embolic events after MMVR, particularly in the immediate postoperative period.

METHODS

Two hundred twenty-nine patients were prospectively recruited: 109 patients (group A+) were randomly assigned to aspirin (200 mg per day) with OAC and 120 patients (group A-) to OAC alone (international normalized ratio 2.5 to 3.5). All patients were subjected to multiplane transesophageal echocardiography at nine days and five months and were followed up for one year.

RESULTS

At nine days and five months, there was a high and comparable incidence of strands in the two groups (group A+: 44%, 58%; group A-: 49%, 63%). However, the incidence of nonobstructive periprosthetic valve thrombi was significantly lower in group A+ at 9 days: 5% versus 13%, p = 0.03. Total thromboembolic events were reduced in group A+ (9% vs. 25%, p = 0.004) although there was an increased incidence of gastrointestinal hemorrhage (7% vs. 0%). Overall mortality was 9% in group A+ and 4% in group A-. Valve-related events were similar in both groups. Early thrombi, but not strands, were associated with higher morbidity, especially thromboembolic events (30% vs. 13%, p = 0.003).

CONCLUSIONS

One year after MMVR, the association of aspirin with OAC reduced thrombi and thromboembolic events, but not morbidity, due to an increase in hemorrhagic complications.

Role of cine-fluoroscopy, transthoracic, and transesophageal echocardiography in patients with suspected prosthetic heart valve thrombosis

Prosthetic heart valve thrombosis (PVT) is a rare but potentially life-threatening complication of heart valve replacement. An effective, quick, and easy diagnostic method is highly desirable. We evaluated the diagnostic efficacy of cine-fluoroscopy (CF), transthoracic (TTE), and transesophageal (TEE) echocardiography in 82 consecutive patients with mechanical valves and suspected PVT. Criteria for PVT were: leaflet(s) motion restriction at CF, increased Doppler gradients at TTE, and evidence of thrombi at TEE. Patients were divided in 4 groups (A, B, C, and D) according to results of CF and TTE. Group A was composed of 24 patients with positive CF and TTE. Thrombi were detected by TEE in all cases, suggesting that when both are positive, CF and TTE correctly identified PVT in all patients so that TEE may be deferred. Group B was composed of 12 patients with positive CF and negative TTE; TEE showed PVT in 4 patients (33%). These patients had very slight leaflet motion restriction as in the case of initial PVT. This suggests that CF compared with Doppler may identify patients with "hemodynamically significant" PVT. The remaining 8 patients in this group had monocuspid prostheses with negative TEE, suggesting that abnormal leaflet motion at CF may be due to functional changes. Therefore, TEE should always be performed in case of monocuspid prostheses with isolated CF abnormalities. Group C was composed of 18 asymptomatic patients with small-sized aortic prostheses and very high Doppler gradients on routine TTE. CF showed normal leaflet motion and TEE ruled out PVT in all cases outlining the diagnostic role of CF in this particular subset. Finally, group D was composed of 28 patients with negative CF and TTE. TEE did not show thrombi in 24 of 28 patients (86%), confirming that, when both yield negative results, CF and TTE are reliable methods to rule out valve thrombosis in most cases. However, in 4 of 28 patients (14%) TEE showed "nonobstructive" prosthetic thrombosis: these patients had mitral prostheses, chronic atrial fibrillation, and 3 of 4 had systemic embolisms. Thus, TEE should be performed in selected patients despite negative CF and TTE results. Sensitivity, specificity, and positive and negative predictive values were 87%, 78%, 80%, and 91% for CF and 75%, 64%, 57%, and 78% for TTE, respectively. CF and TTE correctly identified PVT in 70 of 82 patients (85%). TEE was actually required in 15% of the cases. Thus, CF and TTE are quick, effective, and complementary diagnostic tools to diagnose PVT in most patients. TEE still remains the gold standard technique in selected cases.

Thrombosis of mechanical heart valve prostheses: revisiting the role of fluoroscopy

Prosthetic valve thrombosis is a rare but potentially fatal complication of heart valve replacement. Symptoms may be misleading, yet the condition may rapidly lead to death. A prompt diagnosis is therefore crucial. Ultrasound is the most often used technique for evaluating prosthesis dysfunction. We describe two cases of prosthesis thrombosis with negative Doppler results but with distinctly abnormal leaflet motion at fluoroscopy. A correct diagnosis would have been missed if the Doppler evaluation alone was relied on. Fluoroscopy should always form part of the diagnostic work-up in patients with artificial heart valves.

Management of Nonobstructive Thrombosis of Prosthetic Mitral Valve in Asymptomatic Patients in the Early Postoperative Period: A Study in 20 Patients

The purpose of the present study was to determine the optimal management of nonobstructive thrombi in the early postoperative period after mitral valve replacement.Twenty cases of early thrombi were revealed by systematic transesophageal echocardiography (TEE) performed 9 days after surgical implantation of 229 St. Jude prostheses. Patients were prospectively randomized into two groups: the first group received oral anticoagulants (fluindione), and the second group was treated with a combination of oral anticoagulants and aspirin. The impact of the different therapies on prosthetic thrombi was assessed by systematic TEE at 5 months. All thrombi were nonobstructive and disappeared without fibrinolytic agents or surgery. Seven large (>/= 5 mm) thrombi disappeared: in two patients after reintroduction of intravenous heparin and in five patients with an optimized oral treatment (anticoagulants alone in one patient, anticoagulants associated with aspirin in four patients). In the 13 small (< 5 mm) thrombi, 11 disappeared with an optimized oral treatment: anticoagulants alone in nine patients and anticoagulants associated with aspirin in two patients. The other two small thrombi treated with heparin alone initially persisted and finally disappeared with heparin associated with aspirin. In the group with large thrombi, we recorded a 43% rate of thromboembolic events, with more deaths and severe cerebral embolic events than in the patients with small thrombi. Embolic events were associated with mobile thrombi. An optimized oral anticoagulation therapy with correction of the parameters of Virchow et al. is effective in the treatment of small prosthetic thrombi. For large thrombi, the high rate of thromboembolic events would appear to require a more aggressive approach such as an association of heparin with aspirin and TEE follow-up.

Mechanical Prosthetic Valve Thrombosis: Case Report and Review of the Literature

Mechanical prosthetic valve thrombosis is a life-threatening complication necessitating immediate intervention. The presenting signs and symptoms of this illness are somewhat variable, but physical examination and transesophageal echocardiography enable rapid diagnosis. To avoid catastrophic complications, valve replacement or debridement, or thrombolysis in the correct setting, must be performed without delay. It is not entirely clear which therapy is superior. For any given patient, the risks of thrombolytic therapy, including bleeding, systemic embolism, and failure to restore valvular function, must be weighed against the risks of surgical intervention. Once the decision is made to operate, the choice of valve replacement versus debridement is one best made intraoperatively, upon visual inspection of the valve apparatus. Despite aggressive therapy, morbidity and mortality from prosthetic valve thrombosis and its treatment are not trivial. Fortunately, with current prosthetic devices and aggressive prophylactic anticoagulation, the incidence of prosthetic valve thrombosis remains low. Antiplatelet therapy may offer additional benefit to patients being prophylaxed with warfarin. This report details the case of a woman with aortic and mitral prosthetic valves who presented with heart failure and evidence of severe aortic prosthetic dysfunction after a period of suboptimal anticoagulation. She successfully underwent debridement of the mitral prosthesis and replacement of the aortic valve. The relevant literature is reviewed.