Supremacy of echocardiography in the diagnostic workup of systemic AL amyloidosis

Federico Carbone ^{1 ,2}, Marianna Labate³, Fabrizio Montecucco ^{2 ,4}, and Marco Canepa ^{2 ,3}*

¹First Clinic of Internal Medicine, Department of Internal Medicine, University of Genoa, Genoa, Italy; ²Cardiovascular Disease Unit, IRCCS Ospedale Policlinico San Martino – IRCCS Italian Cardiovascular Network, Genoa, Italy; ³Cardiovascular Disease Unit, Department of Internal Medicine, University of Genoa, Genoa, Italy; and ⁴First Clinic of Internal Medicine, Department of Internal Medicine and Centre of Excellence for Biomedical Research (CEBR), University of Genoa, Genoa, Italy

* Corresponding author. Tel: +390105555834, Fax: +390105556318, Email: [email protected]

A 40-year-old man was admitted to our ward for marked weight loss, four extremities oedema, progressive asthenia, and dyspnoea at exertion in the last 3 months. At admission, laboratory tests showed nephrotic proteinuria (12.28 g/24 h) and Bence-Jones protein (2.70 g/24 h). Lambda light chains were slightly elevated (38.3 mg/L), with a kappa/lambda ratio of 0.45. A steady elevation of cardiac biomarkers was noticed, with troponin I 0.08 μg/L and amino-terminal pro-brain natriuretic peptide 844 μg/L. The electrocardiogram showed sinus rhythm and Q-waves in the antero-septal leads (Panel A). At echocardiography, severe concentric left ventricular hypertrophy (maximal thickness 22 mm) associated with granular sparkling appearance, thickened atrioventricular valves, and mild pericardial effusion was noticed (Panel B, see Supplementary material online, Videos S1–S3). There was a pseudonormal transmitral pattern with increased filling pressure (E/A 1.25, E/E′ 21, Panel C). Speckle tracking analysis showed a significant reduction in global longitudinal strain (−14.3%) with apical sparing (Panel D).

These findings, combined with the recent clinical history and laboratory tests, led to the suspicion of light-chain (AL) amyloidosis with cardiac involvement. A revision of a recent gastric biopsy was requested, which confirmed the presence of amyloid fibril deposits by Congo red stain with immunohistochemical positivity for lambda light chains.

Echocardiography plays a key role in the diagnostic workup of complex systemic diseases such as AL amyloidosis. Cardiologists should interact with internal medicine physicians, maintain a high index of suspicion, and facilitate a quicker diagnosis of this dismal disease.

Supplementary material is available at European Heart Journal online.