Thromboembolic complications in cardiac amyloidosis detected by transesophageal echocardiography

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.

AL cardiac amyloidosis and arterial thromboembolic events

OBJECTIVE

To study the prevalence and characteristics of arterial thromboembolic events (ATEE) in the course of AL amyloidosis.

METHODS

We report the case of a non-anticoagulated patient with AL amyloidosis restrictive cardiomyopathy who developed acute lower limb ischaemia. We then prospectively determined the prevalence of ATEE in all patients with AL amyloidosis who were evaluated in our institution for autologous peripheral stem cell transplantation.

RESULTS

Nine out of 15 non-anticoagulated patients (60%) developed ATEE: ischaemic stroke (3), transient cerebral ischaemic attack (2), multiple peripheral arterial emboli (1), bilateral iliac artery thrombosis (1), bilateral optic nerve ischaemia (1), and mesenteric ischaemia (1). Haemodynamic stasis seemed to play a leading role in the pathophysiology of ATEE, in that all patients were on sinus rhythm and only one had a thrombus on echocardiography. We identified possible contributing factors to ATEE occurrence: concomitant treatments with oestroprogestogen regimen, thalidomide, granulocyte-macrophage colony-stimulating factor (GM-CSF) and extracellular volume disturbances related to the cytapheresis procedure.

CONCLUSION

We report on an unusual frequency of ATEE among patients with AL cardiac amyloidosis. Despite its theoretical risks, anticoagulation should be discussed for patients with amyloid cardiomyopathy.

Intracardiac Thrombosis and Anticoagulation Therapy in Cardiac Amyloidosis

Background— Primary amyloidosis has a poor prognosis as a result of frequent cardiac involvement. We recently reported a high prevalence of intracardiac thrombus in cardiac amyloid patients at autopsy. However, neither the prevalence nor the effect of anticoagulation on intracardiac thrombus has been evaluated antemortem.

Methods and Results— We studied all transthoracic and transesophageal echocardiograms of cardiac amyloid patients at the Mayo Clinic. The prevalence of intracardiac thrombosis, clinical and transthoracic/transesophageal echocardiographic risks for intracardiac thrombosis, and effect of anticoagulation were investigated. We identified 156 patients with cardiac amyloidosis who underwent transesophageal echocardiograms. Amyloidosis was the primary type (AL) in 80; other types occurred in 76 patients, including 56 with the wild transthyretin type, 17 with the mutant transthyretin type, and 3 with the secondary type. Fifth-eight intracardiac thrombi were identified in 42 patients (27%). AL amyloid had more frequent intracardiac thrombus than the other types (35% versus 18%; P =0.02), although the AL patients were younger and had less atrial fibrillation. Multivariate analysis showed that atrial fibrillation, poor left ventricular diastolic function, and lower left atrial appendage emptying velocity were independently associated with increased risk for intracardiac thrombosis, whereas anticoagulation was associated with a significantly decreased risk (odds ratio, 0.09; 95% CI, 0.01 to 0.51; P <0.006).

Conclusions— Intracardiac thrombosis occurs frequently in cardiac amyloid patients, especially in the AL type and in those with atrial fibrillation. Risk for thrombosis increased if left ventricular diastolic dysfunction and atrial mechanical dysfunction were present. Anticoagulation therapy appears protective. Timely screening in high-risk patients may allow early detection of intracardiac thrombus. Anticoagulation should be carefully considered.

Intracardiac thrombosis and embolism in patients with cardiac amyloidosis

BACKGROUND

Patients with primary amyloidosis (AL type) have a poor prognosis, in part due to frequent cardiac involvement. Although intracardiac thrombus has been reported in anecdotal cases, neither its frequency nor its role in causing mortality is known. Furthermore, the clinical and echocardiographic variables that may be associated with thromboembolism in cardiac amyloidosis have not been defined.

METHODS AND RESULTS

A total of 116 autopsy or explanted cases of cardiac amyloidosis (55 AL and 61 other type) were identified in the Mayo Clinic. Forty-six fatal nonamyloid trauma cases served as controls. Each heart was examined for intracardiac thrombus. The cause of death was determined from autopsy and clinical notes. Intracardiac thrombosis was identified in 38 hearts (33%). Twenty-three had 1 thrombus, whereas 15 had 2 to 5 thrombi. Although subjects in the AL group were younger and had less atrial fibrillation than those with other types of amyloidosis, the AL group had significantly more intracardiac thrombus (51% versus 16%, P<0.001) and more fatal embolic events (26% versus 8%, P<0.03). Control hearts had no intracardiac thrombus. The presence of both atrial fibrillation and AL was associated with an extremely high risk for thromboembolism (odds ratio 55.0 [95% confidence interval 8.1 to 1131.4]). By multivariate analysis, AL type (odds ratio 8.4 [95% confidence interval 1.8 to 51.2]) and left ventricular diastolic dysfunction (odds ratio 12.2 [95% confidence interval 2.7 to 72.7]) were independently associated with thromboembolism.

CONCLUSIONS

A high frequency of intracardiac thrombosis was present in cardiac amyloidosis. Furthermore, thromboembolism caused significant fatality. Several risk factors for thromboembolism were identified. Early screening, especially in high-risk patients, and early anticoagulation might reduce morbidity and mortality.

Atrial thrombosis in cardiac amyloidosis: diagnostic contribution of transesophageal echocardiography

Few cases of atrial thrombosis detected by transesophageal echocardiography (TEE) in cardiac amyloidosis have been reported recently. We present the cases of 3 consecutive patients affected by AL-type cardiac amyloidosis, symptomatic for heart failure and in sinus rhythm. All patients had a cardiac restrictive pattern at Doppler examination. TEE showed left atrial thrombus in 2 patients and biatrial thrombi in 1 patient; conventional transthoracic echocardiography detected only 1 left atrial thrombus. Our experience confirms the association between cardiac amyloidosis and atrial thrombosis, even in sinus rhythm. TEE should be considered to assess thromboembolic risk in all cases of cardiac amyloidosis with severe diastolic dysfunction.

[Cardiac pathology of extracardiac origin (II). The cardiac repercussion of amyloidosis and hemochromatosis]

Although rare, amyloidosis and hemochromatosis are the infiltrative diseases in which the heart is more frequently involved. The most common clinical presentation is heart failure with hemodynamic features of restrictive heart disease in cardiac amyloidosis. The diagnosis is often made because of symptoms of other organ involvement, although sometimes cardiac symptoms may be the initial manifestation. The non-specific clinical presentation and the low prevalence of these cardiomyopathies make the diagnosis difficult if the clinician does not suspect it. Once symptoms develop, the evolution is fast. Usually, the unsatisfactory and ineffective treatment of amyloidosis and hemochromatosis contribute to the poor prognosis. The indication of cardiac transplantation in advanced cases is questionable because of the high recurrence of the illness.