[Cardiac amyloidosis: State of art in 2022]

The 3 main types of cardiac amyloidosis are linked to two protein precursors: AL amyloidosis secondary to free light chain deposits in the context of monoclonal gammopathy (mainly of undetermined significance or myeloma) and transthyretin amyloidosis (ATTR), comprising wild-type transthyretin amyloidosis (ATTRwt for wild type) and hereditary transthyretin amyloidosis (ATTRv for variant). These diseases are underdiagnosed and highly prevalent in common cardiac phenotypes in recent studies (heart failure with preserved ejection fraction, severe aortic stenosis, hypertrophic cardiomyopathy). Myocardial amyloid infiltration affects all cardiac structures and clinically promotes predominantly heart failure, conductive disorders and cardioembolic events. The search for extracardiac signs makes it possible to arouse diagnostic suspicion. Electrocardiogram, echocardiography and cardiac MRI can suspect cardiac amyloidosis. The diagnostic confirmation follows a simple algorithm including a systematic search for monoclonal gammapathy and a disphosphonate scintigraphy. Histological proof is necessary in case of AL or ATTR amyloidosis with concomitant monoclonal gammopathy in order to initiate specific treatment. Due to the late disease onset in ATTRv, genetic testing must be routine in all cases of ATTR. These diseases are no longer perceived as incurable since recent therapeutic innovations. A better knowledge of the disease is more than ever necessary.

[Cardiac amyloidosis]

Different types of amyloid deposits involve the heart. Transthyretin and light chain amyloidosis are the most frequent. Diagnostic performance, typing and treatments have improved in the last decade, and prognosis of cardiac amyloidosis is now significantly better thanks to targeted therapies. In this article, we will describe the clinical manifestations of cardiac amyloidosis, the diagnostic approach and detail the characteristics and specific treatments of the most frequent types of cardiac amyloidosis. We will focus on the histopathological aspects, especially on the importance of amyloid typing.

[Diagnosing cardiac amyloidosis in magnetic resonance imaging: The discriminating factors]

Infiltrative cardiomyopathies refers to deposits of substances in the myocardial tissue resulting in a structural abnormality and/or alteration of cardiac function. Cardiac amyloidosis is an extracellular infiltration of amyloid fibril. Cardiac magnetic resonance imaging (MRI) is essential (in the) for its diagnosis. MRI sequences (morphological, viability and parametric mapping) allow a structural and dynamic analysis of the cardiac function as well as a characterization of the myocardial tissue: edema, fatty infiltration, fibrosis. In cardiac amyloidosis, the morphological sequences classically highlight ventricular hypertrophy and thickening of the heart valves. Ventricular functions are assessed by the cine sequences (The cine sequences make it possible to evaluate the ventricular functions.) The viability sequences show (a more diffuse distribution of hypersignals) an abnormal pattern of late gadolinium enhancement in both circumferential and sub-endocardial distribution. The relaxometry sequences or parametric T1 and/or T2 mapping allow the spatial visualization of quantitative changes of the myocardium. The presence of macroscopic myocardial edema or fibrosis causes a prolongation of the native T1 and an increase of the extracellular volume.

[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.