630 CARDIAC AMYLOIDOSIS: THE IMPORTANCE OF THE RIGHT DIAGNOSTIC TOOLS
Authors: Martis Alessandro , Fazzini Luca , Cossu Stefano , Angius Simone , Marchetti Maria Francesca , Mulargia Enrico , Tuveri Maria Francesca , Montisci Roberta 
Published: December 2022

Introduction

Amyloidosis (a.) consists of the build-up of misfolded proteins in the whole body leading to life threatening organ disfunction. The most common form is the AL a., that is the result of kappa or lambda monoclonal light chains deposition as amyloid fibril. Cardiac involvement in AL a. has a high mortality. Once cardiac symptoms reveal, early diagnosis is important in order of the inverse relationship between time after the onset of cardiac symptoms and survival.

Case Report

A 80-y/o male was admitted in our department. Four months before he had an hospitalization in whom a coronarography was performed, showing no emodinamically signifiant lesions, leading to diagnosis of acute coronary syndrome with non occlusive coronary disease. For two months, he experienced progressive dyspnea, edema of the lower limbs and bilateral pleural effusions. On arrival, he was hemodynamically stable, his laboratory results were significant for a pro-BNP of 26,568 pg/ml and high sensitivity troponin T of 359 ng/L but without movement, the electrocardiogram showed sinus rhythm with heart rate of 72 bpm, right bundle block, non specific alterations of repolarization and low voltages. The chest X-ray showed bilateral pleural effusion. A first echocardiogram was performed and showed normal left ventricular systolic function with an ejection fraction of 60%, without wall motion abnormalities, severe concentric hypertrophy, with a left ventricular posterior wall thickness of 16 mm that is over the cutoff proposed by Marume et al., a LV septal WT of 17 mm, over the cutoff of Arvidsson at al., and a granular appearance of the myocardium, seen as hyperrefractile myocardial echoes. There was a moderate-severe diastolic dysfunction (E/E’ ratio of 22). A small pericardial effusion (8 mm) and a right ventricular dilatation (30mm) were present, too. The last parameter is a poor prognostic marker of right heart failure (in our patient there was also a tricuspid insufficiency) and a median survival of four month, as Patel et al. demonstrate. All these parameters are suspicious for storage disease, in particular amyloid deposition. M spike was not shown at serum and urine electrophoresis, and no paraproteins were found in immunofixation. However, increased kappa and lambda free light chains (248 mg/L and 31 mg/L respectively) with an increased serum and urinary kappa/lambda ratio (8.00 and 105.19) were found. Thus, a fine needle aspiration was performed, showing a bone marrow localization of Multiple myeloma (MM). A bone marrow biopsy was done but the result was still unknown at the time of discharge. A negative scintigraphy was performed. The patient was discharged from our department with a diagnosis of chronic heart failure and ongoing investigation about the link between MM and CA. One month later we have seen the result of the bone marrow biopsy that was negative for Congo red staining. During the same month the patient died, so there was no possibility to practice a cardiac biopsy.

Discussion

The purpose of this abstract is to emphasize the importance of fast diagnosis and cardiac biopsy in a characteristic case of clinical and echocardiogram suspicious of CA and a negative scintigraphy. Therefore the cardiac biopsy is preferable to extracardiac biopsy, as fat pad or bone marrow ones, because the cardiac one is more specific and sensitive. The heart of the matter is that it is not possible for all the departments to carry out this procedure in short-term, as in our case, and a non rapid diagnosis is linked with arrhythmic sudden cardiac death but also a rapidly worsening heart failure, as in our patient.