(P101) EARLY DETECTION OF POLYNEUROPATHY IN PATIENTS WITH HEREDITARY TRANSTHYRETIN AMYLOIDOSIS CARDIOMYOPATHY

Background: Hereditary Transthyretin Amyloidosis (hATTR) is a disorder that can present with cardiac, neurological, or mixed signs and symptoms. Patients with hATTR cardiomyopathy (CM), can show early neurological signs which lead to the eventual onset of neurological symptoms. Early detection of polyneuropathy among patients with hATTR-CM can identify candidates for new disease modifying therapies that could significantly reduce mortality and morbidity in these complex patients. The purpose of this study is to examine the role of systematic neurological examinations in patients with hATTR-CM.

METHODS AND RESULTS: Twenty-eight patients with hATTR-CM who did not have any neurological symptoms were enrolled in this prospective study from the Amyloidosis Clinic at the University Health Network. All patients (average age 65.71± 14.23 years; 39.3% males; 60.7% females) were referred to a neurology program specialized in hATTR polyneuropathy (PN). Comprehensive neurological assessments were conducted including a physical examination and nerve conduction studies (NCS). NCS was performed on the upper and lower extremities. Twelve (42.9%) patients did not display any neurological abnormalities on the physical examination, but they had abnormalities on the NCS suggesting the presence of TTR-PN. The abnormalities on the NCS were diffuse sensory greater than motor polyneuropathy. Ten (35.7%) patients displayed clinical and NCS abnormalities. Six (21.4%) patients did not display any clinical or NCS abnormalities. Based on the systematic neurological assessment, twenty-two patients in our study were identified as mixed hATTR phenotype and are to receive specific disease modifying therapies, either Patisiran or Inotersen.

Conclusion: Patients with hATTR-CM can display a wide range of neurological symptoms. In this study, we were able to identify a significant number of patients with abnormal neurological tests in the absence of obvious neurologic signs and symptoms suggesting TTR-PN. Therefore, patients with hATTR-CM should be systematically referred to a specialised neurologist for routine assessment.