Nonbacterial thrombotic endocarditis: a review

[Nonbacterial thrombotic endocarditis and gastric carcinoma]

We report a 74-year-old woman with acute heart failure and recurrent ischemic strokes as the presenting features of a nonbacterial thrombotic endocarditis complicating a gastric adenocarcinoma. The treatment only allowed a few months remission. Diagnosis of nonbacterial thrombotic endocarditis is rarely obtained while the patient is alive. Coagulation abnormalities due to the tumoral process are responsible of the valvular thrombotic process. Anticoagulation with heparin is recommended. Valvular surgery remains controversial.

Non-bacterial thrombotic endocarditis

Non-bacterial thrombotic endocarditis (NBTE) is a disease characterised by the presence of vegetations on cardiac valves, which consist of fibrin and platelet aggregates and devoid of inflammation or bacteria. NBTE has increasingly been recognised as a condition associated with numerous diseases and a potentially life-threatening source of thromboembolism. NBTE is not a common entity; however it is frequently underestimated, probably due to underlying diseases (cancer, autoimmune disorders, HIV). NBTE is difficult to diagnose and relies on strong clinical suspicion. NBTE is also difficult to manage and each case should be individually managed by identifying and treating the underlying pathology. Surgical intervention is not recommended unless the patient is in acute congestive failure.

Nonbacterial Thrombotic Endocarditis in Cancer Patients: Pathogenesis, Diagnosis, and Treatment

Thrombophilia is a well-described consequence of cancer and its treatment. The pathogenesis of this phenomenon is complex and multifactorial. Nonbacterial thrombotic endocarditis (NBTE) is a serious and potentially underdiagnosed manifestation of this prothrombotic state that can cause substantial morbidity in affected patients, most notably recurrent or multiple ischemic cerebrovascular strokes. Diagnosis of NBTE requires a high degree of clinical suspicion as well as the judicious use of two-dimensional echocardiography to document the presence of valvular thrombi. In the absence of contraindications to therapy, treatment consists of systemic anticoagulation, which may ameliorate symptoms and prevent further thromboembolic episodes, as well as control of the underlying malignancy whenever possible.

Healing of wound sutures on the mitral valve: an experimental study

OBJECTIVE

The aim of this study was to examine the histopathological changes that occur during the heading process of a sutured wound on the mitral valve.

METHODS

In 12 mongrel dogs, an incision was made at a right angle to the annulus at the center of the free edge of the anterior mitral leaflet and then sutured. Animals were killed 2-16 weeks later and the wounds were examined histologically.

RESULTS

Two weeks after the operation, fibrin thrombi were found on the atrial surfaces of the wound, and organized thrombi became part of the neointima thereafter. There were capillaries in the thrombi, but only a few extended from the valvular ring. On the ventricular surfaces, fibrous neointima extending from adjacent intima without capillary proliferation covered the wound at 2 weeks. These heading processes started from the valvular ring side of the wound. Processes were delayed near the free edge area, and myxomatous granulation tissue extended from the adjacent spongiosa. There were abundant collagen fibers obscuring the suture line at 4 weeks in the basal region and at 12-16 weeks near the free edge. Calcified deposits with cartilage were found in a thick scar in the basal region at 4 weeks and extended to the central area thereafter.

CONCLUSION

The healing of mitral valvular wounds is slow, especially near the free edge area. The wound is covered by organized thrombi at the atrial surface and by fibrous sheaths at the ventricular surface. These processes should be taken into consideration during the patients' care after valvoplasty, especially during the first several months after surgery.

Nonbacterial thrombotic endocarditis in a ferret (Mustela putorius furo)

A 4-yr-old male ferret (Mustela putorius furo) was presented with a 3-day history of pelvic limb ataxia and weakness. A cellulitis associated with a deep bite wound was identified and initially treated with antibiotics and anti-inflammatory medication. Two weeks later, a grade IV/VI cardiac murmur was identified on physical examination. Echocardiographic examination revealed irregular thickening of the aortic valve leaflets, with normal chamber dimensions and normal systolic function. The ferret's physical condition rapidly deteriorated and it was subsequently euthanatized. Myxomatous degeneration of the aortic valve leaflets, with ulceration and vegetative lesions, and multiorgan infarctions were identified during necropsy. A bacterial etiologic agent was not identified from blood culture or histopathology. Lesions present were consistent with nonbacterial thrombotic endocarditis, a novel condition in the ferret.

Nonbacterial thrombotic endocarditis with recurrent embolic events as manifestation of ovarian neoplasm

We describe the case of a 43-year-old woman with transient ischemic neurologic deficits and recurrent systemic and pulmonary emboli in whom infectious work-up and extensive thrombophilic evaluation were unremarkable. Transesophageal echocardiography (TEE) established the diagnosis of nonbacterial thrombotic endocarditis (NBTE). This is a rare condition often associated with hypercoagulable states or advanced malignancy such as adenocarcinomas, characterized by cardiac vegetations along valvular coaptation lines without destruction of leaflets. In our patient, we diagnosed an ovarian clear cell adenocarcinoma, a malignant disorder that has been rarely reported in association with NBTE. This case illustrates that NBTE can present as an atypical manifestation of malignancy and must be distinguished from infective endocarditis, which implies a different therapeutic strategy. When confronted with findings of NBTE without a clear etiology, an occult neoplasm must be excluded. Anticoagulant therapy is the mainstay of treatment. However, cardiac vegetations may require surgical intervention in rare instances.

Ischaemic stroke with malignancy may often be caused by paradoxical embolism

BACKGROUND

Although ischaemic stroke with malignancy occasionally occurs, the mechanisms of stroke in such cases have not been investigated in detail.

OBJECTIVE

To examine the mechanisms of ischaemic stroke with malignancy, particularly in relation to right-to-left shunt (RLS).

METHODS

Consecutive patients with ischaemic stroke within 24 h of stroke onset were prospectively studied. Contrast saline transcranial Doppler examination was carried out for all patients, to investigate the presence of RLS. When patients with stroke had RLS, deep venous thrombosis (DVT) or pulmonary embolism was assessed to diagnose paradoxical brain embolism.

RESULTS

Participants comprised 184 consecutive patients (115 men and 69 women) with a mean (standard deviation (SD)) age of 73 (11.8) years and mean (SD) National Institutes of Health Stroke Scale (NIHSS) score of 8 (7.4). RLS was detected in 32 of 184 (18%) patients. Malignancy was present in 11 (5%) patients. RLS was more frequent in patients with malignancy than in patients without malignancy (55% v 15%, respectively; p = 0.001). All six patients with RLS and malignancy displayed DVT or pulmonary embolism with severe disability (modified Rankin Scale 4-5) before stroke onset.

CONCLUSION

Paradoxical brain embolism should be considered to be an important mechanism in patients with stroke and malignancy.

Synchronous Primary Endometrial and Ovarian Carcinoma in a Patient With Marantic Endocarditis

BACKGROUND

Nonbacterial thrombotic endocarditis (NBTE), or marantic endocarditis, is a rare form of endocarditis found in patients with advanced malignancy and collagen-vascular disorders. There is limited information about the clinical course of patients with NBTE because the majority of cases are found at the time of autopsy.

CASE

A 38-year-old woman presented to the emergency department with recent onset of chest pain and fatigue. Initial evaluation revealed cardiac valvular disease, and the patient underwent aortic valve replacement. Final pathology revealed nonbacterial thrombotic endocarditis. A metastatic work-up revealed a complex pelvic mass and elevated CA 125. The patient underwent an exploratory laparotomy and was subsequently found to have synchronous primary endometrial and ovarian carcinoma.

CONCLUSION

Nonbacterial thrombotic endocarditis is rare and carries a high mortality. This case is unusual in that the diagnosis of nonbacterial thrombotic endocarditis led to the diagnosis of a gynecologic malignancy.

HAART to heart: HIV-related cardiomyopathy and other cardiovascular complications

More than one million Americans have been diagnosed with human immunodeficiency virus (HIV). Advances in prevention and treatment of HIV have led to an increased life expectancy for patients with HIV infection. Due to their increased life span, HIV+ patients are now presenting to hospitals with an increased number of diverse late-stage complications, such as cardiomyopathy and other cardiovascular conditions. These complications are as a direct or indirect result of HIV disease, HIV treatment modalities, comorbid conditions, dietary and lifestyle factors, and unknown etiologies. Cardiac complications, particularly HIV-related dilated cardiomyopathy, are potentially life-threatening diagnoses, with symptoms that may be minimized with appropriate cardiac-specific assessments and treatments, patient teaching, and collaboration among nurses caring for the HIV-positive client with cardiac disease.

Yield of transesophageal echocardiography for nonbacterial thrombotic endocarditis and other cardiac sources of embolism in cancer patients with cerebral ischemia

Cerebrovascular events occur frequently in patients who succumb to cancer, and nonbacterial thrombotic endocarditis (NBTE) is a frequent postmortem finding in these patients. Despite the excellent diagnostic accuracy of transesophageal echocardiography (TEE) for cardiac sources of cerebral embolism, however, the prevalence of NBTE and other cardioembolic sources in patients with cancer and cerebral ischemia has not been investigated using this modality. This study examined the frequency of cardioembolic findings in consecutive patients with cancer referred to our institution for TEE evaluation of cerebrovascular events. The study cohort comprised 51 patients, of whom 18% had marantic vegetations, and 47% and 55% of whom had definite and definite or probable cardiac sources of embolism, respectively. The present study documents, for the first time, a high frequency of marantic endocarditis and other cardioembolic sources in patients with cancer and cerebrovascular events selected for TEE. This finding has important implications for evaluation and management in this patient population.

Culture-positive and culture-negative endocarditis in patients with cancer: a retrospective observational study, 1994-2004

Endocarditis is uncommon in patients with cancer. The characteristics of culture-positive (CPE) and culture-negative endocarditis (CNE) in high-risk cancer patients are not known; therefore we sought to evaluate the disease characteristics in patients with endocarditis at a comprehensive cancer center. We retrospectively reviewed the transthoracic (TTE) and transesophageal (TEE) echocardiograms obtained from 654 consecutive cancer patients in whom endocarditis was suspected between 1994 and 2004. Endocarditis was confirmed in 45 (7%) of 654 patients using modified Duke University criteria based on information obtained from hospital records and computerized data systems. In 21 (95%) of 22 cases, TEE examinations were diagnostic, and 16 (42%) of 38 patients with initially nondiagnostic TTE studies had the diagnosis confirmed by TEE study; this difference between diagnostic TEE and initial nondiagnostic TTE was significant (p < 0.0001). Among the 26 (58%) patients with CPE, Staphylococcus aureus (35%) was the most common organism isolated, followed by coagulase-negative Staphylococcus species (23%). Eighteen (78%) of 23 patients with a central venous catheter had CPE, whereas only 8 (36%) of 22 patients without a central venous catheter had CPE (odds ratio [OR], 6.3; 95% confidence interval [CI], 1.69-23.53; p < 0.006). Vegetations were larger in patients with CPE than in patients with CNE (median +/- standard deviation, 10 +/- 8.8 vs. 8.7 +/- 3.9 mm). Fifteen patients (58%) with CPE and 10 (53%) with CNE had embolic complications. We note that cutaneous and septic pulmonary emboli were more common in patients with CPE than in patients with CNE (31% vs. 11% and 15% vs. 0%, respectively), whereas embolic cerebrovascular and fatal embolic coronary events were more common in patients with CNE than in those with CPE (37% vs. 12% and 21% vs. 0%, respectively; p = 0.026). The 4-week endocarditis-attributable death rate did not differ significantly between the groups (CPE, 15% vs. CNE, 32%; p = 0.28). On stepwise multivariate regression analysis, patients with neutropenia (OR, 22.52; 95% CI, 2.25-225.48; p < 0.008) and those with embolic cerebrovascular events (OR, 17.07; 95% CI, 1.63-178.45; p < 0.01) had an increased probability of death due to endocarditis. The clinical spectrums of CPE and CNE differed in these patients with cancer. In patients with CNE, embolic cerebrovascular and fatal myocardial infarction were relatively common.

Recurrent embolic strokes and cardiac valvular disease in a patient with non-small cell adenocarcinoma of lung

The etiology and mechanisms of stroke could differ in cancer compared to non-cancer patients due to altered blood coagulability and/or non-bacterial thrombotic endocarditis (NBTE). These conditions could be either missed by using inappropriate diagnostic methods or misinterpreted. For instance, certain techniques (transthoracic echocardiography, TTE) may provide false-negative results and delay appropriate therapy. On the other hand, these patients, by having atypical findings, may challenge the differential between bacterial and sterile valvular heart disease. Cerebrovascular disease in cancer patients is often aggressive with tendency to recurrent events and rapid neurological devastation. Timely diagnosis is crucial. Current treatment approach to NBTE includes anticoagulation. We report a case of multiple embolic strokes in a patient diagnosed with lung cancer. Primary and secondary stroke prevention is discussed with relevant review of the literature.

Nonbacterial thrombotic endocarditis after lung transplantation

Bacteria-free verrucae has been recognized as a condition associated with several clinical conditions such as bone marrow transplantation, malignant tumors, autoimmune disorders, and acquired immunodeficiency syndrome, but it has not been reported in relation to lung transplantation. We report the case of a patient who underwent bilateral lung transplant and died 3 days later. Histologic examination revealed, among other lesions, the presence of nonbacterial thrombotic endocarditis in the right atrium and mitral and tricuspid valves that was not present in the preoperative echocardiographic studies. Even with transesophageal echocardiography, a reliable detection of vegetations may not be possible. Hypoxigenic pulmonary states developed in the course of lung transplant could be the factor that triggers the interaction between the coagulation system, platelets, and endothelial cells that induce the formation of bacteria-free verrucae.

Antibiotic prophylaxis for endocarditis: time to reconsider

Some cardiac conditions require antibiotic prophylaxis for some types of dental treatment to reduce the risk of infective endocarditis (IE). All medical and dental practitioners are familiar with this practice but tend to use different regimens in apparently similar circumstances. Generally, the trend has been to prescribe antibiotics if in doubt. This review explores the evidence for antibiotic prophylaxis to prevent IE: does it work and is it safe? The changing nature of IE, the role of bacteraemia of oral origin and the safety of antibiotics are also reviewed. Most developed countries have national guidelines and their points of similarity and difference are discussed. One can only agree with the authority who describes antibiotic guidelines for endocarditis as being 'like the Dead Sea Scrolls, they are fragmentary, imperfect, capable of various interpretations and (mainly) missing!' Clinical case-controlled studies show that the more widely antibiotics are used, the greater the risk of adverse reactions exceeding the risk of IE. However, the consensus is that antibiotic prophylaxis is mandatory for a small number of high-risk cardiac and high-risk dental procedures. There are a large number of low-risk cardiac and dental procedures in which the risk of adverse reactions to the antibiotics exceeds the risk of IE, where prophylaxis should not be provided. There is an intermediate group of cardiac and dental procedures for which careful individual evaluation should be made to determine whether IE or antibiotics pose the greater risk. These categories are presented. All medical and dental practitioners need to reconsider their approach in light of these current findings.

Malignant pleural/pericardial effusion with tamponade and life-threatening reversible myocardial depression in a case of an initial presentation of lung adenocarcinoma

We present a case of a middle-aged woman in cardiac tamponade. Following pericardiocentesis that removed 1,500 ml of hemorrhagic fluid, the patient exhibited cardiogenic shock; LVEF, at its nadir, on inotrope, was less than 20%. Ventricular function slowly improved, with inotropic support, to the normal range by the 25th day of hospitalization. Cardiac failure in malignancy has often been attributed to multi-system failure; this case showed a hereto unrecognized clinical phenomenon - 'malignancy-associated myopericarditis'. While the direct link of cause and effect cannot be made with certainty, the case should be instructive to other clinicians who encounter similar life-threatening presentations of cardiac decompensation in malignancy.

[Adenocarcinoma-associated nonbacterial thrombotic endocarditis as the cause of recurrent strokes]

We describe a 60-year-old female patient without vascular risk factors diagnosed with cardioembolic ischemic stroke due to an atrial septal aneurysm with a right-to-left shunt. However, further investigation after recurrent strokes revealed a nonbacterial thrombotic endocarditis (NBTE) caused by a metastatic adenocarcinoma. The presented case illustrates the difficulties in establishing the diagnosis of NBTE premortally and points out the importance of repeated echocardiographic evaluations of cardiac valves and serological examination of tumor markers in patients with recurrent strokes of unknown origin.

Surgical treatment of nonbacterial thrombotic endocarditis presenting with stroke

BACKGROUND

Necropsy studies have shown that nonbacterial thrombotic endocarditis (NBTE) may be associated with cerebral infarctions and antemortem diagnosis is now possible. However, the best treatment for patients with NBTE presenting with stroke is not known. We describe three patients presenting with an acute embolic stroke secondary to large,mobile vegetations detected by transthoracic (one case) or transesophageal echocardiography (two cases). All patients underwent surgery for removal of the vegetations to prevent recurrent embolic events; valve replacement was necessary in two cases. The sterile nature of the vegetations was confirmed by pathological examination and negative stains and cultures of the surgical samples. A previously unrecognized hypercoagulable condition was diagnosed in all patients (antiphospholipid antibody syndrome in two cases and disseminated adenocarcinoma in one case).

CONCLUSION

NBTE should be considered among the possible causes of embolic stroke even in the absence of history of cancer, hypercoagulability, or previous embolic manifestations. If NBTE is diagnosed, the possibility of underlying thrombophilia should be thoroughly investigated. Valvular surgery represents a valuable therapeutic alternative in patients with large mobile vegetations, valvular dysfunction or recurrent embolic events despite anticoagulation.

Characteristics and outcome of patients developing endocarditis following hematopoietic stem cell transplantation

Endocarditis is an uncommon complication of hematopoietic stem cell transplantation (HSCT). A retrospective review of 1547 patients who underwent HSCT in Vancouver between January 1986 and December 2001 was performed. In all, 20 cases of endocarditis were identified (1.3% of all patients) with nine patients having received cryopreserved autologous stem cells, six stem cells from a histocompatible sibling and five patients stem cells from an unrelated donor. Five patients had endocarditis diagnosed while alive, a median of 6 months post-HSCT, by transthoracic (four patients) or transesophageal (one patient) echocardiography. The remaining 15 cases of endocarditis were only identified post mortem. The mitral valve was the most frequently involved (10 patients) followed by the aortic valve (six patients); multivalvular disease was noted in five patients. Of the 11 affected allogeneic HSCT patients, 10 had previously developed acute graft-versus-host disease (GVHD). Causative organisms were identified in 11 patients, while nine additional cases were felt to be thrombotic in origin. Of the 20 patients, 19 died with the sole survivor alive 10 years following an aortic valve replacement. Endocarditis is an uncommon complication of HSCT usually involving the cardiac valves on the left side of the heart and is associated with a high mortality rate.

Antithrombotic Therapy in Valvular Heart Disease—Native and Prosthetic

This chapter about antithrombotic therapy in native and prosthetic valvular heart disease is part of the Seventh ACCP Conference on Antithrombotic and Thrombolytic Therapy: Evidence Based Guidelines. Grade 1 recommendations are strong and indicate that the benefits do, or do not, outweigh risks, burden, and costs. Grade 2 suggests that individual patients' values may lead to different choices (for a full understanding of the grading see Guyatt et al, CHEST 2004; 126:179S-187S). Among the key recommendations in this chapter are the following: For patients with rheumatic mitral valve disease and atrial fibrillation (AF), or a history of previous systemic embolism, we recommend long-term oral anticoagulant (OAC) therapy (target international normalized ratio [INR], 2.5; range, 2.0 to 3.0) [Grade 1C+]. For patients with rheumatic mitral valve disease with AF or a history of systemic embolism who suffer systemic embolism while receiving OACs at a therapeutic INR, we recommend adding aspirin, 75 to 100 mg/d (Grade 1C). For those patients unable to take aspirin, we recommend adding dipyridamole, 400 mg/d, or clopidogrel (Grade 1C). In people with mitral valve prolapse (MVP) without history of systemic embolism, unexplained transient ischemic attacks (TIAs), or AF, we recommended against any antithrombotic therapy (Grade 1C). In patients with MVP and documented but unexplained TIAs, we recommend long-term aspirin therapy, 50 to 162 mg/d (Grade 1A). For all patients with mechanical prosthetic heart valves, we recommend vitamin K antagonists (Grade 1C+). For patients with a St. Jude Medical (St. Paul, MN) bileaflet valve in the aortic position, we recommend a target INR of 2.5 (range, 2.0 to 3.0) [Grade 1A]. For patients with tilting disk valves and bileaflet mechanical valves in the mitral position, we recommend a target INR of 3.0 (range, 2.5 to 3.5) [Grade 1C+]. For patients with caged ball or caged disk valves, we suggest a target INR of 3.0 (range, 2.5 to 3.5) in combination with aspirin, 75 to 100 mg/d (Grade 2A). For patients with bioprosthetic valves, we recommend vitamin K antagonists with a target INR of 2.5 (range, 2.0 to 3.0) for the first 3 months after valve insertion in the mitral position (Grade 1C+) and in the aortic position (Grade 2C). For patients with bioprosthetic valves who are in sinus rhythm and do not have AF, we recommend long-term (> 3 months) therapy with aspirin, 75 to 100 mg/d (Grade 1C+).

High prevalence of antiphospholipid antibodies in Asian cancer patients with thrombosis

Thrombotic complications are a significant cause of morbidity and mortality in cancer patients. Studies in Caucasian populations have shown that up to one-third of such patients test positive to antiphospholipid antibodies. Our aim was to determine the prevalence and serotypes of antiphospholipid antibodies in an unselected group of Asian cancer patients with thrombosis. All patients with cancer-related thrombosis seen in the Department of Hematology-Oncology and Radiation Oncology were enrolled in this study. The study period was from April 2000 to May 2001. Antiphospholipid antibodies tests were performed, namely lupus anticoagulant screen, anticardiolipin antibodies (IgG and IgM) and anti-beta-2 glycoprotein I antibodies (B2 GPI) IgG, IgM and IgA. Thirty-three patients were recruited. There were 14 males and 19 females, with an age range of 35-78 years of age. Of those enrolled, there were 25 Chinese, five Malays and three Indians. The patients had several cancer types: 11 (36.7%) patients had adenocarcinoma as the histological cell type. Of the 33 patients, 75.8% had stage IV disease. Arterial thrombosis was seen in eight patients (24.2%), and venous thrombosis occurred in 29 patients (87.9%). Antiphospholipid antibodies were positive in 60.6% of the patients, of which anti-B2GPI IgA antibody was the most prevalent antiphospholipid present (46.9%). The presence of anti-beta-2 glycoprotein I IgA antibody was associated with strokes, extensive and recurrent venous thrombosis, and coincident arterial and venous thrombosis. A high prevalence of antiphospholipid antibodies (60.6%) was found in Asian patients with cancer-related thrombosis. The presence of antiphospholipid antibodies, particularly anti B2GPI IgA, may identify a subset of cancer patients who are at high risk of developing thrombotic complications, and further studies are warranted.

Overview on the incidence and the characteristics of HIV-related opportunistic infections and neoplasms of the heart: impact of highly active antiretroviral therapy

The manifestation of cardiac involvement in the course of HIV infection has been significantly changed since the introduction of highly active antiretroviral therapy. While in the pre-highly active antiretroviral therapy era the predominant cardiac pathology was represented by localization of opportunistic infection, now new forms of heart involvement are described. Among infectious agents, viruses and bacteria caused the majority of infections. The 'classic' opportunistic agents, such as Toxoplasma, non-tuberculous mycobacteria, cytomegalovirus and Cryptococcus, have virtually disappeared. Endocarditis is still the most frequent infectious disease of the heart in HIV-infected patients, occurring mainly in drug users, and with the improvement in prognosis, the need for cardiac surgery is increasing. Tuberculosis, the incidence of which is still high in poor resources settings where antiretroviral drugs are not available, is a frequent cause of pericarditis, frequently evolving into cardiac tamponade. Recent studies suggest the direct role of HIV as the cause of myocarditis and heart vessel pathology. This finding points out the need of improving our knowledge about the pathogenesis, diagnosis and treatment of this kind of complication.

Endothelium and valvular diseases of the heart

It has become increasingly evident that the endothelium plays a critical role in the pathogenesis of valvular heart disease. The endothelium helps regulate vascular tone, inflammation, thrombosis, and vascular remodeling. Dysfunction of the endothelial cells has been linked to many vascular disorders including atherosclerosis. Common valvular diseases such as senile degenerative valve disease, myxomatous (or floppy) valves, rheumatic valves, and infective endocarditis valves show changes in the synthetic, morphologic, and metabolic functions of the valvular endothelial cells. These diseases are active processes related to endothelial cell dysfunction. Endothelial cell dysfunction is caused by mechanical forces, bacterial infection, autoantibodies, and circulating modulators of endothelial cell function. This study reviews the role of endothelial cell dysfunction in the more common valvular diseases. Continued research on endothelial cell dysfunction is crucial to our understanding of valvular heart diseases and may elucidate novel treatment and prevention strategies.

Vascular disorders preceding diagnosis of cancer: distinguishing the causal relationship based on Bradford-Hill guidelines

The literature investigating the association between vascular disorders and malignant neoplasms does not comprehensively review the full spectrum of vascular disorders associated with cancer, or provide proof that cancer is an etiologic factor in the development of these disorders. This paper investigates the causal role of cancer in the pathogenesis of vascular disorders, based on the Bradford-Hill criteria of causation. The Medline database was searched for articles on vascular disorders preceding the diagnosis of cancer (VDPCD). Included in the analysis were vascular disorders caused either by direct tumoral involvement of vessels or by paraneoplastic mechanisms. Vascular disorders caused by adverse reactions to anticancer therapy were excluded from analysis. Seven categories of VDPCDs were recognized: venous thromboembolism, arterial thrombosis and embolism, nonbacterial thrombotic endocarditis, migratory superficial thrombophlebitis, vasculitis, thrombotic microangiopathy, and leukothrombosis. To establish causality of the association between VDPCDs and malignancy, the degree of fulfillment of the Bradford-Hill criteria was assessed. A strong association was found in the literature between venous thromboembolism and cancer (OR 2.3-14.9 and SIR 1.3-4.4). Consistency and temporality of the association were confirmed in all VDPCD variants. Seven Bradford-Hill criteria were fulfilled for cancer associated with venous thromboembolism, six criteria for superficial phlebitis and cancer, and five criteria for each of the other VDPCDs. In conclusion, these data support the causal role of cancer in the pathogenesis of all seven categories of VDPCDs. Recognition of such a causal link between cancer and various vascular disorders may promote an earlier cancer diagnosis.

Two patients with arterial thromboembolism among 311 patients with adenocarcinoma of the pancreas

PURPOSE

To examine the prevalence and characteristics of arterial thromboembolism in patients with adenocarcinoma of the pancreas.

METHODS

Retrospective review of charts of all patients with cancer of the pancreas diagnosed and followed at a regional teaching hospital over a decade.

RESULTS

In total, 320 patients were diagnosed and 311 were available for evaluation. Two patients with arterial thromboembolism were identified (0.65%) and studied. Both had extensive metastatic disease on diagnosis and, soon after, developed an acute arterial occlusion of the iliac and femoral arteries, with no identifiable embolic source (case 1) or acute intestinal infarction due to mesenteric and multiple other embolic arterial occlusions associated with nonbacterial thrombotic endocarditis (NBTE) of the mitral valve (case 2). Both cases had laboratory evidence of disseminated intravascular coagulation and succumbed to their illnesses within a very short time.

CONCLUSION

Arterial occlusion in pancreatic cancer is a rare preterminal event that may be caused by cardiogenic emboli from NBTE or to thrombosis in situ. The pathogenesis is briefly reviewed.

Acute ischemic stroke patterns in infective and nonbacterial thrombotic endocarditis: a diffusion-weighted magnetic resonance imaging study

BACKGROUND AND PURPOSE

Although infective endocarditis (IE) and nonbacterial thrombotic endocarditis (NBTE) are associated with cardioembolic stroke, differences in the nature of these conditions may result in differences in associated stroke patterns. We compared patterns of acute and recurrent ischemic stroke in IE and NBTE, using diffusion-weighted MRI (DWI).

METHODS

Using ICD-9 diagnostic codes and medical record review, we identified 362 patients (387 episodes) with IE and 14 patients with NBTE. Thirty-five patients (with 27 episodes of IE, 9 NBTE) who underwent 36 initial and 29 follow-up DWI scans were selected for this study. DWI lesion size, number, and location were compared between groups and correlated with stroke syndromes and endocarditis features.

RESULTS

DWI was abnormal in all but 2 patients. Four acute stroke patterns were identified: (1) single lesion, (2) territorial infarction, (3) disseminated punctate lesions, and (4) numerous small (<10 mm) and medium (10 to 30 mm) or large (>30 mm) lesions in multiple territories. All patients with NBTE exhibited pattern 4, whereas those with IE exhibited patterns 1, 2, 3, and 4 (6, 2, 8 and 9 episodes, respectively). Seventy-five percent of patients with pattern 3 exhibited the clinical syndrome of embolic encephalopathy. Vegetation size, valve, and organisms had no correlation with stroke patterns.

CONCLUSION

DWI has utility in differentiating between IE and NBTE. Patients with NBTE uniformly have multiple, widely distributed, small and large strokes, whereas patients with IE exhibit a panoply of stroke patterns.

Papillary serous adenocarcinoma of the ovary diagnosed after malignant pericardial tamponade and embolic stroke

BACKGROUND

Epithelial carcinomas of the ovary are predominantly an intraperitoneal disease. Reports of epithelial ovarian carcinomas metastatic to the pericardium are rare.

CASE

A 43-year-old woman was admitted with symptoms of a pericardial tamponade, as well as an embolic cerebrovascular accident, and transferred to the ICU where a pericardiocentesis was performed. Cytology revealed malignant cells in the pericardial fluid. CT scan of the abdomen and pelvis revealed bilateral pelvic masses. A laparotomy revealed a papillary serous adenocarcinoma of ovarian primary and an infarcted spleen with capsular tumor metastases. The malignant cells in the pericardial fluid were consistent with the ovarian primary.

CONCLUSION

Ovarian cancer metastasis to the heart and pericardium presented an aggressive variant of tumor spread with significant morbidity and subsequent mortality.

Surgical pathology of nonbacterial thrombotic endocarditis in 30 patients, 1985-2000

OBJECTIVE

To describe the causes, complications, and histological appearance of nonbacterial thrombotic endocarditis (NBTE) in a surgical population compared with those in previously reported autopsy series.

PATIENTS AND METHODS

Cases were identified by reviewing the surgical pathology reports for all cardiac valvular specimens removed at Mayo Clinic, Rochester, Minn., between 1985 and 2000. Archived microscopic slides and medical records were reviewed for each study patient.

RESULTS

The study group consisted of 30 patients (20 female and 10 male), with a mean age of 49 years (range, 15-89 years). Of these 30 patients, 28 had single valve involvement (19 mitral, 8 aortic, and 1 tricuspid), and 2 had involvement of both their mitral and aortic valves. An underlying immune-mediated disorder was identified in 18 patients (60%), including primary antiphospholipid syndrome (in 8), rheumatic heart disease (in 6), systemic lupus erythematosus (in 2), and rheumatoid arthritis (in 2), 15 (83%) of whom were women. Of the remaining 12 patients with no autoimmune disease, only 5 (42%) were women. No patient had metastatic malignant disease or disseminated intravascular coagulopathy. Systemic embolization was documented in 10 patients (33%), 8 of whom had cerebral involvement. Valvular vegetations were visualized by echocardiography before surgery in 8 patients and were suspected but not confirmed preoperatively in 1 patient. All vegetations consisted primarily of platelets and fibrin. The site and appearance of vegetations did not vary with the underlying disease state.

CONCLUSIONS

In contrast to previously reported autopsy series, NBTE in a surgical population was more commonly associated with autoimmune disorders than malignancy or disseminated intravascular coagulopathy. Women were affected twice as often as men. Systemic embolization, particularly to the brain, was prominent in both surgical and autopsy series. Vegetations had a similar appearance regardless of the specific underlying disease. An antemortem diagnosis of NBTE in a patient with no known risk factors should prompt a search not only for occult malignancy, as suggested by autopsy studies, but also for autoimmune or rheumatic diseases, particularly the antiphospholipid syndrome.

Epidemiology of cardiovascular involvement in HIV disease and AIDS

The epidemiology of cardiac complications related to HIV including cardiomyopathy, increased left ventricular mass, myocarditis, pericardial effusion, endocarditis, and malignancy are discussed. A large number of HIV-infected individuals will present with cardiac complications in the next decade as chronic viral infection, co-infections, drug therapy, and immunosuppression affect the heart. Understanding the nature and course of cardiac illness related to HIV infection will allow appropriate monitoring, early intervention and therapy, and will provide a baseline to evaluate the effects of new therapeutic regimens such as highly active antiretroviral therapy on the cardiovascular system.

Diagnosis of culture-negative endocarditis: the role of the Duke criteria and the impact of transesophageal echocardiography

BACKGROUND

The Duke criteria have been shown to be more sensitive than the von Reyn criteria in the diagnosis of culture-positive endocarditis but to date have not been fully validated for culture-negative endocarditis (CNE). The aim of this study was (1) to compare the diagnostic accuracy of the Duke criteria versus clinical judgment and the von Reyn criteria in CNE and (2) to assess the diagnostic impact of transesophageal echocardiography (TEE) on the Duke criteria in CNE.

METHODS

The study group consisted of 49 patients with suspected CNE in whom the presence (n = 32) or absence (n = 17) of endocarditis was confirmed by surgery, autopsy, or both. All patients underwent transthoracic echocardiography (TTE) and TEE. They were classified into a Duke category initially with TTE data only, and then the Duke categories were reevaluated with the additional TEE data.

RESULTS

The Duke criteria demonstrated a significantly higher sensitivity (72%) than the von Reyn criteria (28%; P =.0008) and a higher specificity (100%) than clinical judgment (76%; P =.02). No major differences were noted between sensitivities of the Duke criteria and clinical judgement. TEE significantly augmented the capacity to diagnose CNE by Duke criteria versus TTE (P <.05).

CONCLUSIONS

The Duke criteria are of high diagnostic validity for the conduction of clinical studies on CNE. They have the potential to affect clinical decision-making, based on the higher specificity versus clinical judgment. TEE appears to be crucial for the diagnosis of CNE when the Duke criteria are applied. The diagnostic differentiation between CNE, sclerotic valve degeneration, and nonbacterial thrombotic endocarditis remains a challenge.

Antithrombotic therapy in valvular heart disease

Whether antithrombotic therapy in elderly patients differs from that in younger populations depends on whether the risk for such bleeding differs in the elderly. Regarding long-term therapy with warfarin derivatives, evidence shows that there is a difference. The anticoagulation response to warfarin is exaggerated with advancing age. This article discusses antithrombotic therapies for valvular heart disease, including bioprosthetic and mechanical prosthetic heart valves, aspirin and dipyridamole in combination with oral anticoagulant therapy, antiplatelet agents alone or in combination with very low dose warfarin, tilting disk valves, valve position, first-generation valves compared with modern valves, interruption of anticoagulant therapy, and miscellaneous indications for antithrombotic therapy.

Endocarditis due to rare and fastidious bacteria

The etiologic diagnosis of infective endocarditis is easily made in the presence of continuous bacteremia with gram-positive cocci. However, the blood culture may contain a bacterium rarely associated with endocarditis, such as Lactobacillus spp., Klebsiella spp., or nontoxigenic Corynebacterium, Salmonella, Gemella, Campylobacter, Aeromonas, Yersinia, Nocardia, Pasteurella, Listeria, or Erysipelothrix spp., that requires further investigation to establish the relationship with endocarditis, or the blood culture may be uninformative despite a supportive clinical evaluation. In the latter case, the etiologic agents are either fastidious extracellular or intracellular bacteria. Fastidious extracellular bacteria such as Abiotrophia, HACEK group bacteria, Clostridium, Brucella, Legionella, Mycobacterium, and Bartonella spp. need supplemented media, prolonged incubation time, and special culture conditions. Intracellular bacteria such as Coxiella burnetii cannot be isolated routinely. The two most prevalent etiologic agents of culture-negative endocarditis are C. burnetti and Bartonella spp. Their diagnosis is usually carried out serologically. A systemic pathologic examination of excised heart valves including periodic acid-Schiff (PAS) staining and molecular methods has allowed the identification of Whipple's bacillus endocarditis. Pathologic examination of the valve using special staining, such as Warthin-Starry, Gimenez, and PAS, and broad-spectrum PCR should be performed systematically when no etiologic diagnosis is evident through routine laboratory evaluation.

Echocardiography in nonbacterial thrombotic endocarditis: from autopsy to clinical entity

Bacteria-free verrucae, frequently termed "non-bacterial thrombotic endocarditis," have been recognized in autoimmune disorders as well as in neo-plastic diseases. The antemortem diagnosis of non-bacterial thrombotic endocarditis is rare, and most existing data result from postmortem examinations. In 3 prospective echocardiographic studies we found typical cardiac valvular lesions in patients with primary antiphospholipid syndrome, myelo-proliferative disorders, and solid malignant tumors. Cardiac lesions associated with these 3 different entities had common echocardiographic appearance and correlated positively with thromboembolic events. The possibility of common pathogenesis is suggested, and clinical significance is discussed.

Development of non-bacterial thrombotic endocarditis after percutaneous transvenous mitral commissurotomy for severely calcified mitral stenosis

We encountered a case of mitral stenosis, complicated with non-bacterial thrombotic endocarditis, that developed after percutaneous transvenous mitral commissurotomy (PTMC). A 71-year-old female Japanese patient had severe congestive heart failure and underwent PTMC for critical and severely calcified mitral stenosis. Four weeks later, the echocardiogram demonstrated a highly echoic protrusion in the postero-medial commissure of the mitral valve. There was little evidence of inflammation at that time. She had been anticoagulated adequately since she was admitted. The patient underwent replacement of the mitral valve. She did not show any evidence of systemic embolization. Microscopic evaluation showed only organized thrombus but no evidence of inflammation in the mitral valve. Silent development of non-bacterial thrombotic endocarditis after PTMC should be recognized as a rare but potentially lethal complication of PTMC.

A case of confirmed nonbacterial thrombotic endocarditis with correlative transesophageal echocardiographic findings

The diagnosis of nonbacterial thrombotic endocarditis is rarely made during life. We describe a patient with non-Hodgkin's lymphoma with evidence of systemic embolism in which transesophageal echocardiography was useful in establishing the diagnosis. The clinical and echocardiographic features of nonbacterial thrombotic endocarditis should be remembered when a valvular mass is seen on echocardiography.

Multiple cerebral infarctions from nonbacterial thrombotic endocarditis mimicking cerebral vasculitis

Primary vasculitis of the central nervous system (PVCNS) is an uncommon disorder that can present with a variety of symptoms, making diagnosis and management difficult. We describe a case of cerebral infarction that occurred from nonbacterial thrombotic endocarditis (NBTE) and presented with clinical and radiologic imaging features that suggested PVCNS. The patient was a 58-year-old woman with left hemiparesis, aphasia, and episodic confusion. Magnetic resonance imaging of the brain demonstrated multifocal lesions consistent with infarction involving both cerebral hemispheres, and cerebral angiography showed changes consistent with vasculitis. Although brain biopsy findings were normal, the patient was treated for presumed vasculitis with cyclophosphamide and prednisone. Four months later respiratory failure secondary to polymicrobial pneumonia and adult respiratory distress syndrome developed, and she died. Autopsy revealed multiple infarcts in the heart, lungs, right kidney, spleen, and brain. Multiple thrombotic platelet-fibrin vegetations consistent with NBTE were found on all cardiac valves. Examination of the brain revealed no evidence of active or healed vasculitis. Cerebral angiography may show findings that suggest vasculitis, but it is not diagnostic, as several other conditions may cause similar changes. Nonbacterial thrombotic endocarditis may cause multiple cerebral infarctions and can be difficult to distinguish from vasculitis, as specific diagnostic tests for PVCNS are lacking.