AL cardiac amyloidosis and arterial thromboembolic events

Association of Atrial Fibrillation With Stroke and Dementia Accounting for Left Atrial Function and Size

BACKGROUND

Atrial fibrillation (AF) is associated with higher risks of ischemic stroke (IS) and dementia. Whether alterations in left atrial (LA) function or size-atrial myopathy-confound these associations remains unknown.

OBJECTIVES

The purpose of this study was to examine the association of prevalent and incident AF with ischemic stroke and dementia in the ARIC (Atherosclerosis Risk In Communities) study, adjusting for LA function and size.

METHODS

Participants at visit 5 (2011-2013) with echocardiographic LA function (reservoir, conduit, contractile strain, and emptying fraction) and size (maximal, minimal volume index) data, and without prevalent stroke or dementia were followed through 2019. For analysis, we used time-varying Cox regression.

RESULTS

Among 5,458 participants (1,193 with AF, mean age of 76 years) in the stroke analysis and 5,461 participants (1,205 with AF, mean age of 75 years) in the dementia analysis, 209 participants developed ischemic stroke, and 773 developed dementia over 7.1 years (median). In a demographic and risk factor-adjusted model, AF was significantly associated with ischemic stroke (HR, 1.63; 95% CI: 1.11-2.37) and dementia (HR: 1.38, 95% CI: 1.13-1.70). After additionally adjusting for LA reservoir strain, these associations were attenuated and no longer statistically significant (stroke [HR: 1.33, 95% CI: 0.88-2.00], dementia [HR: 1.15, 95% CI: 0.92-1.43]). Associations with ischemic stroke and dementia were also attenuated and not statistically significant after adjustment for LA contractile strain, emptying fraction, and minimal volume index.

CONCLUSIONS

AF-ischemic stroke and AF-dementia associations were not statistically significant after adjusting for measures of atrial myopathy. This proof-of-concept analysis does not support AF as an independent risk factor for ischemic stroke and dementia.

Atrial Fibrillation, Thromboembolic Risk, and Anticoagulation in Cardiac Amyloidosis: A Review

Cardiac amyloidosis (CA) is caused by extracellular myocardial deposition of amyloid fibrils that are primary derived either from misfolding of transthyretin (ATTR) or light-chain (AL) proteins. CA is associated with atrial fibrillation, potentiated by electromechanical changes as a result of amyloid infiltration in the myocardium. CA also predisposes to thromboembolism and could potentially simultaneously elevate bleeding risk. In this review, we aim to explore and compare the prevalence and pathophysiological mechanisms of atrial fibrillation and thromboembolism in ATTR and AL, examine bleeding risk and factors that promote bleeding, and compare anticoagulation strategies in CA. Finally, we highlight knowledge gaps in the field of thromboembolism in CA to guide future research.

Thromboembolism and bleeding in systemic amyloidosis: a review

The assessment of both thromboembolic and haemorrhagic risks and their management in systemic amyloidosis have been poorly emphasized so far. This narrative review summarizes main evidence from literature with clinical perspective. The rate of thromboembolic events is as high as 5-10% amyloidosis patients, at least in patients with cardiac involvement, with deleterious impact on prognosis. The most known pro-thrombotic factors are heart failure, atrial fibrillation, and atrial myopathy. Atrial fibrillation could occur in 20% to 75% of systemic amyloidosis patients. Cardiac thrombi are frequently observed in patients, particularly in immunoglobulin light chains (AL) amyloidosis, up to 30%, and it is advised to look for them systematically before cardioversion. In AL amyloidosis, nephrotic syndrome and the use of immunomodulatory drugs also favour thrombosis. On the other hand, the bleeding risk increases because of frequent amyloid digestive involvement as well as factor X deficiency, renal failure, and increased risk of dysautonomia-related fall.

Electromechanical dissociation of left atrium in patients with Cardiac Amyloidosis by Magnetic Resonance: Prognostic and clinical correlates

OBJECTIVES

Left atrial (LA) function is an important marker of hemodynamic status in cardiac amyloidosis (CA), and its characterization may provide relevant prognostic information. We sought to assess the prevalence and prognostic impact of LA dysfunction by cardiac magnetic resonance (CMR) in patients with CA.

METHODS

We performed CMR in 80 consecutive patients with CA, including 38 with AL (47%) and 42 with ATTR (53%). LA function was assessed by acquiring short axis cine steady-state free precession (SSFP) covering the entire chamber. The atrial emptying fraction (AEF) was calculated as the ratio between the difference of LA maximal and minimal volume to LA maximal volume, expressed as percentage. Severe atrial dysfunction was defined as AEF ≤ 14%.

RESULTS

Mean AEF was 18% (13-35%). Overall, AEF ≤ 14% was present in 19 patients (24%), including 21% of those in sinus rhythm (SR) with no history of atrial fibrillation (AF). After a median of 3 years (IQR 2-4), 36 patients (44%) died of cardiac causes. Patients with AEF ≤ 14% showed increased cardiac mortality, with an independent OR of 4.2 (95 IC 2.1-8.2, P < 0.0001). Of note, AEF ≤ 14% was the stronger independent predictor of cardiac death. Patients in SR with AEF ≤ 14% had worse outcome than those with AF.

CONCLUSIONS

Severe impairment of LA contractile function was present in three-quarters of patients with CA, and was prevalent irrespective of CA etiology, both in the presence and absence of AF. Severe LA dysfunction was associated with an independent 4-fold increase in risk for cardiac death at three years.

Cardiac amyloidosis presenting with recurrent ischaemic strokes

A 72-year-old man presented to our service with sudden onset right-sided weakness, aphasia and gaze palsy with diplopia. CT angiogram demonstrated an acute thrombotic occlusion of the distal basilar artery, a basilar infarct and the patient underwent successful thrombectomy. ECG and telemetry demonstrated slow atrial fibrillation (AF). His transthoracic echocardiogram (TTE) showed a reduced ejection fraction of 25% with global hypo-kinesis, a dilated left ventricle (LV) and LV hypertrophy (LVH). Repeat TTE appeared suspicious for an infiltrative cardiomyopathy with LVH and a speckled appearance to the myocardium. Approximately 10 months later, he suffered another ischaemic stroke post-elective cardioversion for AF while on anticoagulation. Cardiac MRI demonstrated areas of delayed gadolinium enhancement consistent with amyloidosis. Fat pad biopsy was positive for amyloidosis. Our patient has made an excellent recovery from the ischaemic strokes and is being managed in our heart failure clinic.

Temporal artery involvement in AL amyloidosis: an important differential diagnosis for giant cell arteritis. A case report and literature review

AL amyloidosis (AL) is a systemic disorder due to extracellular tissue deposition of amyloid fibrils, composed of immunoglobulin light chains. Since the description of AL involving temporal arteries in 1986, this disorder has been known as one of the differential diagnoses of giant cell arteritis (GCA). We encountered a case of an elderly female presenting with headache and tender and enlarged temporal arteries, that was pathologically diagnosed with temporal artery involvement of AL due to Bence-Jones-type MM. To our knowledge, this was the first case of AL with temporal artery involvement in Japan, that presented with GCA-like features. Literature review of AL cases with temporal artery involvement showed close similarity between these disorders, but suggested that vasculature involvement (extremity claudication, kidney or heart), macroglossia, carpal tunnel syndrome and normal or low (<0.5 mg/dL) CRP levels may predict AL rather than GCA. Physicians should keep in mind that AL involving temporal arteries can be a pitfall in the diagnosis of GCA, as seen in our and previous cases.

Renal Infarction and Its Consequences for Renal Function in Patients With Cardiac Amyloidosis

OBJECTIVE

To describe the prevalence of and risk factors for renal infarction (RI) in patients with cardiac amyloidosis.

PATIENTS AND METHODS

We evaluated 87 patients with cardiac amyloidosis who underwent renal technetium-99m-labeled dimercaptosuccinic acid scintigraphy in the Amyloidosis Referral Center of Henri-Mondor Hospital from October 1, 2015, through February 28, 2018.

RESULTS

Three groups of patients were identified according to the underlying amyloidosis disorder: AL amyloidosis in 24 patients, mutated-transthyretin amyloidosis in 24 patients, and wild-type transthyretin amyloidosis in 39 patients. Patients with wild-type transthyretin amyloidosis were older (P<.001), more likely to be men (P=.02), to have arrhythmic heart diseases (P<.001), and to be receiving anticoagulation treatment (P<.001). Patients with AL amyloidosis had significantly higher N-terminal pro-B-type natriuretic peptide levels (P=.02) and were more likely to have nephrotic syndrome (P<.001). Renal infarction was detected in 18 patients (20.7%), at similar frequencies in the various groups. Baseline urinary protein to creatinine ratio was the only parameter for which a significant difference (P=.03) was found between patients with and without RI diagnoses. The likelihood of RI diagnosis was 47.1% (8 of 17) in the presence of AKI and 14.5% (10 of 69) in its absence (P=.003). Overall, heart transplant-censored patient survival did not differ significantly between patients with and without RI (P=.64), but death- and heart transplant-censored renal survival was significantly lower in patients with RI (P<.001).

CONCLUSION

Our study suggests that prevalence of RI in patients with cardiac amyloidosis is higher than previously thought, regardless of the underlying amyloidosis disorder. Acute kidney injury in a patient with cardiac amyloidosis should alert clinicians to the possibility of RI.

Cerebral embolism secondary to cardiac amyloidosis: A case report and literature review

Cardiac amyloidosis (CA) describes a group of heterogeneous diseases that are characterized by the extracellular fibril deposition of amyloid protein in the myocardium. The abnormal protein is usually derived from light-chain amyloidosis, mutant transthyretin amyloidosis and wild-type transthyretin. Patients with ischemic strokes and amyloidosis have been sporadically reported, however, they are not well summarized. In the present study, a case of cerebral ischemic stroke, secondary to CA was described. This patient presented with dyspnea on exertion, without any evidence of atrial fibrillation. A biopsy revealed deposition of amyloid in the myocardium and Congo Red staining was positive. He suffered from acute infarction of left basal ganglia, resulting from occlusion of the left middle cerebral arterial 6 months prior to admission. However, re-examination of cerebral magnetic resonance imaging in the present hospital revealed an old infarction in the region of the left basal ganglia with a normal appearance of the left middle cerebral artery. Transesophageal echocardiography (TEE) and cardiac magnetic resonance (CMR) both discovered intra-cardiac thrombi, confirming the diagnosis of cardiogenic cerebral embolism. The present study indicates that patients with CA may additionally present with cardiogenic cerebral embolism, and TEE and CMR imaging may help to avoid missing the presence of intra-cardiac thrombi.

Bilateral kidney infarction due to primary Al amyloidosis: a first case report

Primary Amyloid Light-chain (AL) amyloidosis is a rare form of plasma cell dyscrasia characterized by tissue deposition of monoclonal immunoglobulin light chain. Kidney involvement is the most frequent manifestation, and patients usually present with glomerular disease.We report an exceptional case of bilateral kidney infarcts caused by AL amyloidosis. A 34-years-old man presented with progressive dyspnea, loin pain, recurrent macroscopic hematuria, and acute kidney injury. Computed tomography showed bilateral kidney infarcts.The diagnosis of AL amyloidosis was established on the kidney biopsy with the characterization of major vascular amyloid deposits that selectively stained with antilambda light chain antibody. An amyloid restrictive cardiomyopathy was also present, responsible for the life-threatening conduction disturbance, but without patent cardioembolic disease. The patient then underwent emergency heart transplantation, followed by a conventional chemotherapy with bortezomib, melphalan, and dexamethasone. More than 3 years later, the patient has subnormal renal function, a well-functioning heart transplant, and a sustained hematologic response.In addition to the very uncommon presentation, this case illustrates the tremendous progress that has occurred in the management of severe forms of AL amyloidosis.

Recent advances in the diagnosis and management of cardiac amyloidosis

The heart is commonly involved in various forms of amyloidosis and cardiomyopathy is a major cause of morbidity and mortality in these patients. Diagnosis of cardiac amyloidosis is often delayed due to nonspecific presenting symptoms and failure to recognize early signs of amyloid heart disease on routine cardiac imaging. Treatment of cardiac amyloidosis depends upon the type of amyloid protein. Systemic chemotherapy with or without stem cell transplantation is used to treat immunoglobulin-related amyloidosis and liver transplantation is used for familial transthyretin amyloidosis in select patients. Clinical trials with siRNA for the treatment of transthyretin amyloid cardiomyopathies and amyloid protein stabilizers are ongoing. Prognosis depends on the type of amyloid protein with poorer outcomes noted in immunoglobulin light-chain amyloidosis. Supportive care forms the cornerstone of management and advancements in cardiac imaging and proteomics are expected to positively impact our ability to diagnose, prognosticate and treat cardiac amyloidosis.

Light-chain amyloidosis mimicking giant cell arteritis in a bilateral anterior ischemic optic neuropathy case

Background

Herein we report a case of bilateral anterior ischemic optic neuropathy (AION) showing histopathologic evidence of AL-amyloidosis of the temporal arteries. It is known that light-chain (AL) amyloidosis may rarely affect the temporal arteries, mimicking giant cell arteritis, while, to our knowledge, the association between AL-amyloidosis and AION was not previously described.

Case presentation

A 64 year-old woman with AL-amyloidosis secondary to a monoclonal gammopathy of undetermined significance (MGUS) referred to our hospital for acute painless drop of vision due to bilateral AION. Age greater than 50 years, high erythrocyte sedimentation rate (ESR), and bilateral AION were suggestive of giant cell arteritis (GCA). However, a temporal artery biopsy excluded GCA, showing segmental stenosis of the lumen caused by amyloidosis of the artery wall.

Conclusions

The present case shows that AL-amyloidosis may present with AION, high ESR, and temporal artery involvement, mimicking GCA. In patients with monoclonal gammopathies, C-reactive protein may be a more specific index of GCA compared with the ESR. Patient medical history and pathology are crucial for a correct diagnosis.

[Cardiac amyloidosis: a case series of 14 patients, description and prognosis]

PURPOSE

Cardiac amyloidosis is rare. The objective of this study was to report on a case series of 14 patients with cardiac amyloidosis and to study the prognostic factors.

METHODS

Monocentric retrospective study of all adult patients who presented with cardiac amyloidosis, diagnosed at the Georges-Pompidou European hospital in Paris between 2003 and 2011.

RESULTS

Fourteen patients were identified (10 men and four women). Median age at diagnosis was 66.5 years. Twelve patients were diagnosed with AL amyloidosis, one with AA amyloidosis, and one with transthyretin amyloidosis. All patients presented cardiac manifestations: heart failure (n=9), rhythm disorders (n=6). Eight patients presented extra-cardiac manifestations of amyloidosis: renal (n=8), gastrointestinal (n=5). Troponin serum level was increased in eight patients and BNP level was superior to 400 pg/L in 12 patients. When performed, the cardiac magnetic resonance imaging (MRI) showed, in six patients out of seven, chamber dilatation, concentric hypertrophy or late enhancement. Among patients with cardiac failure at diagnosis (n=9), seven died with a median survival of 1 month duration. Factors of poor prognosis were, in our study, heart failure, elevated levels of troponin and BNP, and the AL amyloidosis subtype.

CONCLUSION

Cardiac amyloidosis, especially the AL type, has a very poor prognosis, essentially because of an underlying multiple myeloma and heart failure.

Cardiomyopathy in neurological disorders

According to the American Heart Association, cardiomyopathies are classified as primary (solely or predominantly confined to heart muscle), secondary (those showing pathological myocardial involvement as part of a neuromuscular disorder) and those in which cardiomyopathy is the first/predominant manifestation of a neuromuscular disorder. Cardiomyopathies may be further classified as hypertrophic cardiomyopathy, dilated cardiomyopathy, restrictive cardiomyopathy, arrhythmogenic right ventricular cardiomyopathy, or unclassified cardiomyopathy (noncompaction, Takotsubo-cardiomyopathy). This review focuses on secondary cardiomyopathies and those in which cardiomyopathy is the predominant manifestation of a myopathy. Any of them may cause neurological disease, and any of them may be a manifestation of a neurological disorder. Neurological disease most frequently caused by cardiomyopathies is ischemic stroke, followed by transitory ischemic attack, syncope, or vertigo. Neurological disease, which most frequently manifests with cardiomyopathies are the neuromuscular disorders. Most commonly associated with cardiomyopathies are muscular dystrophies, myofibrillar myopathies, congenital myopathies and metabolic myopathies. Management of neurological disease caused by cardiomyopathies is not at variance from the same neurological disorders due to other causes. Management of secondary cardiomyopathies is not different from that of cardiomyopathies due to other causes either. Patients with neuromuscular disorders require early cardiologic investigations and close follow-ups, patients with cardiomyopathies require neurological investigation and avoidance of muscle toxic medication if a neuromuscular disorder is diagnosed. Which patients with cardiomyopathy profit most from primary stroke prevention is unsolved and requires further investigations.

Multiple arterial and venous thromboembolic complications in AL amyloidosis and cardiac involvement: a case report and literature review

A 41-year-old woman with immunoglobulin light chain (AL) systemic amyloidosis with cardiac and gastrointestinal involvement developed multiple arterial and venous thromboembolic complications. Treatment with unfractionated heparin was complicated by life-threatening gastrointestinal bleeding. Work up for hereditary thrombophilia was unrevealing. Treatment with cyclophosphamide, bortezomib and dexamethasone combination regimen led to hematologic response without further thromboembolic complications. While thromboembolic complications have been reported in AL amyloidosis and cardiac involvement, this unique case highlights the complexity of the disease, the various pathogenic mechanisms at play and the difficult management decisions necessary in caring for these complex patients. A literature review of thrombembolic complications in patients with amyloidosis is presented.

Acute limb ischemia in a patient with cardiac amyloidosis: a case report

Introduction

Cardiac amyloidosis is a manifestation of several systemic diseases known as amyloidoses. Arterial thromboembolic complications have not been reported to occur frequently, although the pathophysiology of cardiovascular amyloidosis would theoretically predispose to such manifestations.

Case presentation

We present the case of a 52-year-old woman, who suffered from cardiac amyloidosis and was admitted to our hospital for left acute limb ischemia. An urgent embolectomy was performed, improving her clinical condition and the pathologoanatomic examination of the embolus revealed deposition of amyloid.

Conclusion

Peripheral arterial thromboembolic events in patients with amyloidosis are rare. An antiplatelet treatment is recommended in such patients with cardiac amyloidosis for the prevention of embolism.

Molecular and cellular aspects of protein misfolding and disease

Proteins are essential elements for life. They are building blocks of all organisms and the operators of cellular functions. Humans produce a repertoire of at least 30,000 different proteins, each with a different role. Each protein has its own unique sequence and shape (native conformation) to fulfill its specific function. The appearance of incorrectly shaped (misfolded) proteins occurs on exposure to environmental changes. Protein misfolding and the subsequent aggregation is associated with various, often highly debilitating, diseases for which no sufficient cure is available yet. In the first part of this review we summarize the structural composition of proteins and the current knowledge of underlying forces that lead proteins to lose their native structure. In the second and third parts we describe the molecular and cellular mechanisms that are associated with protein misfolding in disease. Finally, in the last part we portray recent efforts to develop treatments for protein misfolding diseases.

Potentiation of fluindione or warfarin by dexamethasone in multiple myeloma and AL amyloidosis

OBJECTIVES

Patients with primary systemic (AL) amyloidosis or multiple myeloma are frequently treated with cyclic dexamethasone (DXM) courses and often require oral anticoagulants. We previously reported a strong potentiation of oral anticoagulants with intravenous methylprednisolone and observed a similar potentiation with DXM in 3 patients, which led us to prospectively investigate the interaction between DXM and oral anticoagulants.

METHODS

Nine patients with multiple myeloma (n=6) or AL amyloidosis (n=3), including 6 prospective patients, taking fluindione (n=8) or warfarin (n=1), were studied for a total of 10 cycles. DXM (40 mg/day for 4 days every 28 days) was administered alone (n=4) or with melphalan (n=5). One patient was studied for 2 consecutive cycles after a moderate increase in the international normalized ratio (INR) during the first course of DXM. International normalized ratio (INR) was measured serially during DXM administration. Plasma oral anticoagulant concentrations were measured for 5 cycles.

RESULTS

The mean INR increased from 2.75 (range: 1.80-3.6) at baseline to 5.22 (3.09-7.07) after DXM. Oral anticoagulants were transiently stopped during 8 cycles and 1 mg oral vitamin K was given during 2. No serious bleeding was observed. Plasma oral anticoagulant concentrations increased after DXM administration. In controls receiving DXM without oral anticoagulants, DXM alone did not increase prothrombin time.

CONCLUSION

High dose DXM can potentiate oral anticoagulants and elevate INR substantially. INR should therefore be monitored repeatedly during concomitant administration of these 2 drugs to allow individual adaptation of oral anticoagulant doses.

Activation of Human Platelets by Misfolded Proteins

OBJECTIVE

Protein misfolding diseases result from the deposition of insoluble protein aggregates that often contain fibrils called amyloid. Amyloids are found in Alzheimer disease, atherosclerosis, diabetes mellitus, and systemic amyloidosis, which are diseases where platelet activation might be implicated.

METHODS AND RESULTS

We induced amyloid properties in 6 unrelated proteins and found that all induced platelet aggregation in contrast to fresh controls. Amyloid-induced platelet aggregation was independent of thromboxane A2 formation and ADP secretion but enhanced by feedback stimulation through these pathways. Treatments that raised cAMP (iloprost), sequestered Ca2+ (BAPTA-AM) or prevented amyloid-platelet interaction (sRAGE, tissue-type plasminogen activator [tPA]) induced almost complete inhibition. Modulation of the function of CD36 (CD36-/- mice), p38(MAPK) (SB203580), COX-1 (indomethacin), and glycoprotein Ib alpha (Nk-protease, 6D1 antibody) induced approximately 50% inhibition. Interference with fibrinogen binding (RGDS) revealed a major contribution of alphaIIb beta3-independent aggregation (agglutination).

CONCLUSIONS

Protein misfolding resulting in the appearance of amyloid induces platelet aggregation. Amyloid activates platelets through 2 pathways: one is through CD36, p38(MAPK), thromboxane A2-mediated induction of aggregation; the other is through glycoprotein Ib alpha-mediated aggregation and agglutination. The platelet stimulating properties of amyloid might explain the enhanced platelet activation observed in many diseases accompanied by the appearance of misfolded proteins with amyloid.