Nonbacterial thrombotic endocarditis: a review

An echocardiographic study of infective endocarditis, with special reference to patients with HIV

OBJECTIVE

The aim was to describe the echocardiographic features of patients with infective endocarditis (IE), and to compare the manifestations of IE in HIV-positive versus HIV-negative patients.

METHODS

The study was prospective in nature and screened patients referred to Inkosi Albert Luthuli Hospital (IALCH) with suspected IE between 2004 and 2007. Only patients with a definite diagnosis of IE according to the modified Duke criteria were enrolled for the purpose of the study. Inkosi Albert Luthuli hospital is an 842-bed tertiary referral centre, serving a KwaZulu-Natal population of 10 million people, who are of various races.

RESULTS

During this period, 91 patients were screened for IE. Seventy-seven (HIV infected, n = 17) satisfied the criteria for a definite diagnosis of IE. Blood cultures were positive in 46% of cases. The commonest organism was S aureus. Most patients had advanced valve disruption with heart failure and high peri-operative mortality. The clinical profile in the HIV-infected patients was similar to the that of the non-infected patients. The prevalence of echocardiographic complications (abscesses, aneurysms, perforations, fistulae and chordal ruptures) was 50.6% in the whole group. Except for the presence of leaflet aneurysms and root abscesses in four advanced (CD4 counts > 250 /mm(3)) HIV-infected cases, complications were not more frequent in the HIV-infected group.

CONCLUSION

There was a high rate of culture-negative cases in this study, probably related to prior antibiotic usage; in this setting the modified Duke criteria have diagnostic limitations. No significant differences in the clinical presentation of infective endocarditis were noted between HIV-infected and HIV-negative patients.

Cancer-related coagulopathies

The association between cancer and thrombosis is known for years. Besides the well-recognized connection between venous thromboembolism and malignancies, there are, however, also other manifestations of cancer-related activation of coagulation and (micro)vascular dysfunction. In fact, coagulation derangements and vascular disturbances in patients with cancer cover a wide spectrum of diseases and various clinical manifestations. In this review we will highlight the mechanisms that play a role in the systemic activation of coagulation in cancer patients, in its most severe form manifested as disseminated intravascular coagulation. Clinically, disseminated intravascular coagulation (DIC) in cancer has in general a less fulminant presentation than the types of DIC complicating sepsis and trauma. A more gradual, but also more chronic, systemic activation of coagulation can proceed subclinically. The relationship between venous thromboembolism and cancer as a consequence of the hypercoagulability will be discussed as well. Furthermore, the role of perturbed endothelium in the pathogenesis of microvascular dysfunction and microangiopathy in particular in the setting of cancer and chemo- or radiotherapy will be reviewed.

Multiple hypercoagulability disorders at presentation of non-small-cell lung cancer

Hypercoagulability disorders are commonly encountered in clinical situations in patients with a variety of cancers. However, several hypercoagulability disorders presenting as first symptoms or signs in cancer patients have rarely been reported. We herein described a case of a woman with adenocarcinoma of the lung presenting with deep vein thrombosis, nonbacterial thrombotic endocarditis, recurrent cerebral embolic infarction, and heart failure.

Nonbacterial Thrombotic Endocarditis in a Patient with Bowel Infarction due to Mesenteric Vein Thrombosis

Ante mortem cases of venous thrombosis in patients with nonbacterial thrombotic endocarditis (NBTE) have not yet been reported. We describe a rare case of NBTE in a patient with mesenteric vein thrombosis. A healthy 37-year-old man with abdominal pain and fever underwent emergency small bowel resection due to bowel ischemia resulting from mesenteric vein thrombosis. Transthoracic echocardiography revealed multiple mobile masses attached to the anterior leaflet of the mitral valves and their chordae tendineae. On suspicion of infective endocarditis, the cardiac masses were excised through open-heart surgery. However, pathologic reviews were compatible with NBTE. The patient was stable after the cardiac surgery and was treated with warfarin. Laboratory and imaging findings regarding his hypercoagulable condition were all negative.

Etiology of valvular heart disease

The etiology of valvular heart diseases (VHD) has changed in the last 50 years in the industrialized countries. A significant reduction in the incidence of rheumatic fever and its sequelae, increase in life expectancy, recognition of new causes of VHD and advancement in technology are responsible for the metamorphosis of the etiology of VHD. Heritable disorders of connective tissue (marfan syndrome, Ehlers-Danlos syndrome, adult polycystic kidney disease, floppy mitral valve/mitral valve prolapse); congenital heart disease (bicuspid aortic valve); inflammatory/immunologic disorders (rheumatic fever, AIDS, Kawasaki disease, syphilis, seronegative spondyloarthropathies, systemic lupus erythematosus, antiphospholipid syndrome); endocardial disorders (nonbacteremic thrombotic endocarditis, infective endocarditis, endomyocardial fibroelastosis); myocardial dysfunction (ischemic heart disease, dilated cardiomyopathy, hypertrophic cardiomyopathy); diseases and disorders of other organs (chronic renal failure, carcinoid heart disease); aging (calcific aortic stenosis, mitral annular calcification); postinterventional valvular disease; drugs and physical agents are all clinical entities associated with VHD. It should be emphasized that VHDs still constitute a major health problem which will increase with the aging population.

Neurologic complications of valvular heart disease

Valvular heart disease (VHD) is frequently associated with neurologic complications; cerebral embolism is the most common of these since thrombus formation results from the abnormalities in the valvular surfaces or from the anatomic and physiologic changes associated with valve dysfunction, such as atrial or ventricular enlargement, intracardiac thrombi, and cardiac dysrhythmias. Prosthetic heart valves, particularly mechanical valves, are very thrombogenic, which explains the high risk of thromboembolism and the need for anticoagulation for the prevention of embolism. Infective endocarditis is a disease process with protean manifestations that include not only cerebral embolism but also intracranial hemorrhage, mycotic aneurysms, and systemic manifestations such as fever and encephalopathy. Other neurologic complications include nonbacterial thrombotic endocarditis, a process associated with systemic diseases such as cancer and systemic lupus erythematosus. For many of these conditions, anticoagulation is the mainstay of treatment to prevent cerebral embolism, therefore it is the potential complications of anticoagulation that can explain other neurologic complications in patients with VHD. The prevention and management of these complications requires an understanding of their natural history in order to balance the risks posed by valvular disease itself against the risks and benefits associated with treatment.

Marantic endocarditis presenting with multifocal neurological symptoms

Non-bacterial thrombotic endocarditis (NBTE), also known as marantic endocarditis, has been reported to occur in 0.3-9.3% of the adult population at autopsy. NBTE associated with malignancy is an underrecognised cause of thromboembolic disorders. The clinical spectrum encountered and investigation results can be non-specific, often mimicking other acute conditions such as infective endocarditis. We describe the case of a 34-year-old woman with non-localising and multifocal neurological symptoms, who was subsequently diagnosed with NBTE secondary to a resectable primary lung adenocarcinoma.

Systemic inflammatory response and local cytokine expression in porcine models of endocarditis

The knowledge of systemic inflammation and local cytokine expression in porcine endocarditis models is limited, though it could provide valuable information about the pathogenesis and comparability to human endocarditis. Analyses of bacteriology and hematology were performed on blood samples from pigs with non-bacterial thrombotic endocarditis (NBTE, n = 11), Staphylococcus aureus infective endocarditis (IE, n = 2), animals with S. aureus sepsis without endocarditis (n = 2) and controls (n = 2). Furthermore, immunohistochemistry was used to examine the local expression of IL-1β and IL-8. Bacterial blood cultures were continuously positive in IE pigs from inoculation to euthanasia, and negative in all other pigs at all times. The total white blood cell counts and total neutrophil counts were massively elevated in pigs with IE. Local IL-1β and IL-8 expression in IE pigs were moderate to high, and high, respectively. In addition, slight local expression of IL-1β and IL-8 was present in some NBTE pigs. In the IE model, both the systemic inflammatory response and the high local expression of IL-8 were comparable to the human disease. Furthermore, the results indicate IL-1β and IL-8 as important contributors in the endocarditis pathogenesis.

Cardiac valve involvement in systemic diseases: a review

Increasing age and new trends of mixed populations have newly aroused interest in valvular heart disease in the developed countries still in need of new clinical insights. In the clinical setting of systemic diseases, the proper assessment of cardiovascular abnormalities may be challenging, and the characterization of valvular involvement might help to recognize the underlying disease and cardiac sequelae. Prompt identification of valvular lesions may, therefore, also be useful for differential diagnosis. This article reviews the cardiac involvement in systemic diseases from etiology and background definition to echocardiographic assessment and clinical interpretation.

Nonbacterial thrombotic endocarditis leading to acute heart failure due to aortic stenosis in a patient with lung cancer

We herein report an autopsied case of a patient with adenocarcinoma of the lungs who developed nonbacterial thrombotic endocarditis (NBTE) that caused acute heart failure (AHF) due to acute aortic stenosis (AS). A 37-year-old man was admitted to our hospital due to chest pain and fever. He was diagnosed as having Stage IV lung cancer. Following the administration of chemotherapy, the patient presented with acute onset of dyspnea. He was diagnosed with having AHF based on his clinical course and physical findings, and ultimately he died without responding to treatment. The autopsy revealed that NBTE caused acute AS leading to AHF.

Antithrombotic and thrombolytic therapy for valvular disease: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines

BACKGROUND

Antithrombotic therapy in valvular disease is important to mitigate thromboembolism, but the hemorrhagic risk imposed must be considered.

METHODS

The methods of this guideline follow those described in Methodology for the Development of Antithrombotic Therapy and Prevention of Thrombosis Guidelines. Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines in this supplement.

RESULTS

In rheumatic mitral disease, we recommend vitamin K antagonist (VKA) therapy when the left atrial diameter is > 55 mm (Grade 2C) or when complicated by left atrial thrombus (Grade 1A). In candidates for percutaneous mitral valvotomy with left atrial thrombus, we recommend VKA therapy until thrombus resolution, and we recommend abandoning valvotomy if the thrombus fails to resolve (Grade 1A). In patients with patent foramen ovale (PFO) and stroke or transient ischemic attack, we recommend initial aspirin therapy (Grade 1B) and suggest substitution of VKA if recurrence (Grade 2C). In patients with cryptogenic stroke and DVT and a PFO, we recommend VKA therapy for 3 months (Grade 1B) and consideration of PFO closure (Grade 2C). We recommend against the use of anticoagulant (Grade 1C) and antiplatelet therapy (Grade 1B) for native valve endocarditis. We suggest holding VKA therapy until the patient is stabilized without neurologic complications for infective endocarditis of a prosthetic valve (Grade 2C). In the first 3 months after bioprosthetic valve implantation, we recommend aspirin for aortic valves (Grade 2C), the addition of clopidogrel to aspirin if the aortic valve is transcatheter (Grade 2C), and VKA therapy with a target international normalized ratio (INR) of 2.5 for mitral valves (Grade 2C). After 3 months, we suggest aspirin therapy (Grade 2C). We recommend early bridging of mechanical valve patients to VKA therapy with unfractionated heparin (DVT dosing) or low-molecular-weight heparin (Grade 2C). We recommend long-term VKA therapy for all mechanical valves (Grade 1B): target INR 2.5 for aortic (Grade 1B) and 3.0 for mitral or double valve (Grade 2C). In patients with mechanical valves at low bleeding risk, we suggest the addition of low-dose aspirin (50-100 mg/d) (Grade 1B). In valve repair patients, we suggest aspirin therapy (Grade 2C). In patients with thrombosed prosthetic valve, we recommend fibrinolysis for right-sided valves and left-sided valves with thrombus area < 0.8 cm(2) (Grade 2C). For patients with left-sided prosthetic valve thrombosis and thrombus area ≥ 0.8 cm(2), we recommend early surgery (Grade 2C).

CONCLUSIONS

These antithrombotic guidelines provide recommendations based on the optimal balance of thrombotic and hemorrhagic risk.

Antithrombotic therapy in cardiac embolism

Anticoagulation is indicated in most cardioembolic ischemic strokes for secondary prevention. In many cardiac conditions, anticoagulation is also indication for primary stroke prevention, mainly when associated to vascular risk factors. Anticoagulation should be started as soon as possible, as it is safe even in moderate acute strokes. The efficacy of early anticoagulation after cardioembolic stroke in relation to outcome has not been assessed adequately, but there is evidence from animal models and clinical studies that anticoagulation with unfractionated heparin is associated with a better outcome mediated in part by its anti-inflammatory properties.

Culture-negative bivalvular endocarditis with myocardial destruction in a patient with systemic lupus erythematosus: a case report

Culture-negative endocarditis has long been associated with systemic lupus erythematosus, but is usually asymptomatic or involves a single valve. We present a patient with destructive culture-negative endocarditis that remains without a microbial etiology despite an exhaustive workup using advanced diagnostic techniques in a patient with systemic lupus erythematosus.

Antithrombotic medication for cardioembolic stroke prevention

Embolism of cardiac origin accounts for about 20% of ischemic strokes. Nonvalvular atrial fibrillation is the most frequent cause of cardioembolic stroke. Approximately 1% of population is affected by atrial fibrillation, and its prevalence is growing with ageing in the modern world. Strokes due to cardioembolism are in general severe and prone to early recurrence and have a higher long-term risk of recurrence and mortality. Despite its enormous preventive potential, continuous oral anticoagulation is prescribed for less than half of patients with atrial fibrillation who have risk factors for cardioembolism and no contraindications for anticoagulation. Available evidence does not support routine immediate anticoagulation of acute cardioembolic stroke. Anticoagulation therapy's associated risk of hemorrhage and monitoring requirements have encouraged the investigation of alternative therapies for individuals with atrial fibrillation. New anticoagulants being tested for prevention of stroke are low-molecular-weight heparins (LMWH), unfractionated heparin, factor Xa inhibitors, or direct thrombin inhibitors like dabigatran etexilate and rivaroxaban. The later exhibit stable pharmacokinetics obviating the need for coagulation monitoring or dose titration, and they lack clinically significant food or drug interaction. Moreover, they offer another potential that includes fixed dosing, oral administration, and rapid onset of action. There are several concerns regarding potential harm, including an increased risk for hepatotoxicity, clinically significant bleeding, and acute coronary events. Therefore, additional trials and postmarketing surveillance will be needed.

Nonbacterial thrombotic endocarditis associated with cancer of unknown origin complicated with thrombus in the left auricular appendage: case report

A 63-year-old man was admitted to our hospital with a complaint of right lateroabdominal pain. He was diagnosed with metastatic colon cancer, and then developed multiple brain embolic infarctions 7 days after admission. Transesophageal echocardiography showed that mobile, echo-dense masses were attached to the anterior and posterior mitral valve leaflet. Furthermore, there was a thrombus in the left auricular appendage despite sinus rhythm. These findings led to a diagnosis of suspected infectious endocarditis with subsequent multiple brain infarctions. The patient's general condition worsened and he died 13 days after admission. An autopsy was performed, and, while poorly differentiated cancer was observed in multiple organs, no primary tumor could be identified. Histological analysis showed that the masses of the mitral valve consisted mainly of fibrin without bacteria or oncocytes. This patient was therefore diagnosed with nonbacterial thrombotic endocarditis associated with cancer of unknown origin complicated with thrombus in the left auricular appendage.

Peripheral arterial ischemic events in cancer patients

Thromboembolic complications are the second leading cause of death in cancer patients. In contrast to the large body of literature on venous thromboembolism (VTE), relatively few reports have focused on the pathogenesis, incidence, management and outcomes of arterial thromboembolic events in patients with malignancy. The purpose of this article is to review the current literature on the etiology, mechanisms, and prognosis of arterial thromboembolic events in cancer patients and outline appropriate screening and management guidelines that may help lower the rates of morbidity and mortality related to these events.

Transthoracic and transesophageal echocardiography for the indication of suspected infective endocarditis: vegetations, blood cultures and imaging

BACKGROUND

The aim of this study was to investigate the ability of transthoracic echocardiography (TTE) to detect vegetations and the relationship between blood cultures and transesophageal echocardiography (TEE).

METHODS

Five hundred eleven TTE and TEE pairs performed to evaluate endocarditis were retrospectively analyzed. Vegetation on TTE, prosthetic valve, change in regurgitation, and blood cultures were correlated with vegetation on TEE.

RESULTS

TTE detected 45% of vegetations seen on TEE. There was no difference for prosthetic valves. Prosthetic valves (odds ratio, 1.7; P = .03) and increased regurgitation (odds ratio, 1.7; P = .01) were associated with vegetations on TEE; staphylococcal bacteremia and fungemia were not. Negative blood cultures were associated with negative results on TEE (P < .0001), but 27% of patients with prosthetic valves had culture-negative endocarditis or nonbacterial thrombotic endocarditis, and 6% had abscesses missed by TTE.

CONCLUSION

This study demonstrates a limited capacity of TTE to detect vegetations. TEE may be an appropriate initial study to evaluate prosthetic valves. TEE for culture-negative endocarditis deserves further study.

[Ischemic strokes as a presenting feature of marantic endocarditis despite heparin treatment]

We report on two patients hospitalized in intensive care unit for ischemic strokes presenting the feature of marantic endocarditis complicating lung's adenocarcinoma. These two cases turned out to be very interesting because of the occurrence of ischemic strokes even though the patients were receiving the recommended treatment, namely anticoagulation with heparin, in well-adjusted doses. The management of nonbacterial thrombotic endocarditis remains a challenge and its mortality is still high.

Primary coronary embolism as an unusual manifestation of nonbacterial thrombotic endocarditis in a patient with gastric cancer

Nonbacterial thrombotic endocarditis (NBTE) is a rare clinical condition characterized by the presence of sterile vegetations on valvular leaflets Gross and Friedberg (1936). The most frequent cause of NBTE is antiphospholipid syndrome Hughson and et al. (1993); malignancy, through an intrinsic condition of hypercoagulability, is the second most common cause Thomas (2001). Systemic thromboembolic complications are frequently associated with this condition, but coronary embolism is not common. We report the case of a patient with NBTE secondary to gastric adenocarcinoma with clinical symptoms of coronary and systemic emboli.

"Grey zone" patterns of unexplained endocarditis: still a challenge for clinical decision making

The authors report two cases of unexplained active inflammatory endocarditis with totally different clinical presentations. The patients had undergone previous mitral repair surgery and were referred for multiple soft mobile masses on the mitral ring without clinical or laboratory signs of endocarditis. Serologic screening and blood culture results were negative, including those for specific fastidious bacteria, as well as immunologic tests to rule out "nonbacterial thrombotic endocarditis." Before new surgery, both patients were treated with long-term antibiotic and anticoagulant therapy, with no significant changes in clinical setting and echocardiographic patterns. In neither case was it possible to characterize a specific microorganism: the intraoperative findings were highly evocative of active endocarditis with a macroscopic infiltration of the mitral ring, and culture results from surgical material and valvular tissue were negative.

Nonbacterial thrombotic endocarditis complicated with stage Ia ovarian cancer

Nonbacterial thrombotic endocarditis (NBTE) commonly occurs in advanced malignancies associated with a cancer-related hypercoagulable state, but the prevalence of NBTE in patients with less advanced malignancies is unknown. A 46-year-old woman had multiple thromboembolic events and disseminated intravascular coagulation on admission. Transthoracic echocardiography showed several growths on the mitral valve. Pelvic magnetic resonance imaging revealed a rapidly enlarging large tumor. In spite of anticoagulation therapy, she died 1.5 months after admission. At autopsy, NBTE with stage Ia ovarian cancer was diagnosed. In cases of higher-growth rate tumors with abundant necrosis, NBTE may occur in early-stage (even in stage Ia) ovarian cancer. In the majority of stage Ia ovarian cancers, curative surgical resection can be done. Prognostic improvement may be gained by such positive intervention, although this depends on the patient's general condition when NBTE occurs. With tumor resection, there is a possibility that the patient will recover from the hypercoagulable state and a poor outcome will be avoided.

The role of endothelial cell biology in endocarditis

The treatment of endocarditis remains a challenge for physicians, even in times of modern antibiotic treatment. Depending on its cause, endocarditis can either be of infectious or non-infectious origin. Infective endocarditis is caused by bacterial (or fungal) pathogens, and the clinical course is critically dependent on the virulence factors of the specific microorganisms involved. Therefore, the clinical type of endocarditis can be divided into an acute and more aggressive form and a subacute form (endocarditis lenta). Much of our knowledge regarding the pathogenesis of infective endocarditis is based on studies of the virulence of Staphylococcus aureus, which has become the most frequent cause of infective endocarditis nowadays. However, independently of the underlying cause of endocarditis (infectious or noninfectious), the pathogenesis involves the damage and disturbance of endothelial function and the formation of associated "vegetation". Surprisingly little is known about the specific role of the endothelium in the pathogenesis of endocarditis. This review will thus give insights into current knowledge of the pathogenesis of endocarditis with a focus on the role of the endothelium.

First-ever stroke as initial presentation of systemic cancer

BACKGROUND

Stroke is a frequent complication in patients with cancer, occurring in nearly 15% of patients with cancer. However, cerebrovascular disease as the first manifestation of cancer has rarely been reported.

METHODS

We retrospectively reviewed all 5106 patients admitted for ischemic stroke to our stroke department between 1991 to 2004, and identified a group of 24 patients (0.4%) who had an underlying malignancy.

RESULTS

The mean age of the 24 patients was 52 +/- 4.1 years and 62.5% were women. Vascular risk factors were found in only 41% of patients. The principal mechanisms of stroke pathogenesis were nonbacterial thrombotic endocarditis (8/24), diffuse intravascular coagulation (6/24), and atherosclerosis (5/24). The most frequent neoplasms were lung and breast cancer. All patients but 4 were diagnosed with an underlying malignancy at the second ischemic event. Mean follow-up of surviving patients was 29 months (3-60). Nineteen patients died (79%), with a median survival of 58 days after cerebral infarction.

CONCLUSIONS

A systemic cancer workup should be considered in patients in whom stroke origin is unclear or who have an early vascular recurrence. Stroke as the first manifestation of an underlying malignancy is mostly secondary to specific cancer-related causes. Outcome is poor and correlates with both severity of neurologic disability and the stage of tumor.

Heart and vessel pathology underlying brain infarction in 142 stroke patients

OBJECTIVE

This study was designed to determine the histopathological characteristics of cardiac and vascular lesions responsible for various subtypes of ischemic stroke.

METHODS

Postmortem pathological examination was performed on 142 patients who died within 30 days of the onset of ischemic stroke in the National Cardiovascular Center, Osaka, Japan.

RESULTS

The numbers of cases with autopsy-proven diagnoses of atherothrombotic, cardioembolic, and lacunar strokes, ischemic stroke of other determined causes, and ischemic stroke of undetermined cause were 17, 107, 2, 12, and 4, respectively. Thrombi that developed at the culprit plaques of the cerebral arteries were responsible for atherothrombotic stroke. In 70% of the cases with cardioembolic stroke, the presence of thrombi as potential embolic sources were confirmed in the heart or, in some cases, in the venous circulation of patients with patent foramen ovale and tetralogy of Fallot.

INTERPRETATION

In most atherothrombotic strokes, fibrin- and platelet-rich thrombi of various thicknesses develop at the culprit plaques of the cerebral arteries, which are finally occluded with fibrin- and red-cell-rich thrombi (red thrombi). In most cardioembolic strokes, red thrombi generated in the heart or peripheral veins are dislodged to embolize the cerebral arteries.