Abstract 17139: Hereditary Transthyretin Amyloidosis With Exclusive Cardiac Phenotype: A Multicenter Italian Study
Introduction and hypothesis: In hereditary transthyretin amyloidosis (ATTR), cardiac involvement usually occurs in association with neurologic signs. Few variants responsible for isolated cardiomyopathy, mimicking hypertrophic cardiomyopathy (HCM), have been identified in well-defined populations, such as Val122Ile mutation in African-Americans. However little is known about the frequency of an “exclusively cardiologic” phenotype among mixed Caucasians. We assessed its prevalence and clinical features in a nationwide Italian setting.
Methods: We conducted a cohort study of 154 patients with a clear-cut diagnosis of ATTR at two large Italian centers with a coordinated amyloidosis network and a shared dedicated database. classified The phenotype at diagnosis was classified as: exclusively cardiologic (echocardiographically defined amyloidotic cardiomyopathy in the absence of any sign of peripheral/autonomic neuropathy); exclusively neurologic; mixed cardiologic/neurologic.
Results: Prevalence of phenotypes and patients' characteristics are shown in the Table. The echocardiographic profile of patients with exclusively cardiologic phenotype was characterized by concentric left ventricular (LV) “hypertrophy”, slightly increased LV end-diastolic diameter and moderately reduced LV ejection fraction. QRS voltages were reduced only in 1/3 of the cases. During a median follow-up of 32 months, 4 of 18 patients with exclusively cardiologic phenotype (Gly57Arg, Tyr78Phe, Ile68Leu, Val14Leu mutations) developed mild neurologic (sensorimotor) symptoms.
Conclusions: A clinically relevant subset of mixed Caucasian ATTR patients present with an exclusively cardiologic phenotype, mimicking HCM or Senile Systemic Amyloidosis. Thus, the possibility of ATTR must be considered also in Caucasians with unexplained LV “hypertrophy”, even in the absence of overt neurologic manifestations.
- © 2010 by American Heart Association, Inc.