Long term survival in patients with cardiac amyloidosis. Prevalence and characterisation during follow-up.

BACKGROUND AND AIMS: Cardiac amyloidosis (CA) is usually characterised by a poor outcome in the short-term; clinical and instrumental features are heterogeneous and could characterise subgroups with different prognoses. The aim of our study was to describe a subgroup of patients with CA showing an impressive favourable long-term survival. METHODS: Out of 50 patients (males 65%, 63 ± 11 years) with an echocardiographic and bioptic diagnosis of CA observed from 1991 to 2009, we selected a subgroup of patients surviving more than 50 months from diagnosis (group 1). We described their features at enrolment and during follow-up, comparing them with patients surviving less than 12 months (group 2). RESULTS: We found seven patients (14%) belonging to group 1 and 26 (52%) to group 2. Four out of seven long term survivors suffered from AL amyloidosis, in one case the underlying aetiology was a chronic inflammatory disease, while in two cases remained unknown. At enrolment, group 1 patients showed higher systolic blood pressure with respect to group 2 (140 ± 25 vs. 112 ± 18 mmHg, respectively, p=0.011), and a less thick interventricular septum (IVS) (IVS thickness > 15 mm in 29% vs. 69% of patients, p = 0.049). No patient of group 1 presented left ventricular restrictive filling pattern (0 vs. 31% in group 1 and 2 respectively, p = 0.035), atrial fibrillation (0 vs. 35%, p = 0.024), or progression towards a more severe disease during follow-up. CONCLUSIONS: A not negligible proportion of patients with CA can have a long-term survival. They showed a less severe disease at diagnosis, with substantial stability over time. Further studies on larger populations are necessary to understand the mechanisms underlying this more favourable natural history of the disease. Copyright © 2013 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). Published by Elsevier B.V. All rights reserved.