Prevalence of Wild-type TTR Cardiac Amyloidosis in Patients With Polyneuropathy of Unknown Cause.

Prevalence of Wild-type TTR Cardiac Amyloidosis in Patients With Polyneuropathy of Unknown Cause: a Prospective Monocentric Study (CAP-TTR)

To investigate to what extent chronic axonal length-dependent polyneuropathy (CAP) and/or small-fiber neuropathy (SFN) is part of early non-cardiac manifestations of wild-type TTR cardiac amyloidosis (wtTTR-CA).

Consequently, explore whether this could ultimately lead to faster diagnosis and clinical outcome of wild-type TTR cardiac amyloidosis (wtTTR-CA).

Patients with chronic axonal length-dependent polyneuropathy (CAP) and/or small-fiber neuropathy (SFN) without well-defined cause will be recruited after a neurological standard routine work-up with NCS (Nerve conduction study) test, EMG, and Sudoscan®, previously performed at the neurology department of UZ-Brussel in normal clinical setting. All participants will be invited to the Neurology and Cardiology department for one visit on one day, for the following assessments:

Following exams will be performed:

• assessment of symptoms, severity, and duration of the polyneuropathy and the use of NTSS-6 and COMPASS31 score for mapping somatosensory and autonomic symptoms
• evaluation of objective polyneuropathy signs, using following scales: mPND, NIS
• Kansas City Cardiomyopathy Questionnaire (KCCQ)
• Electrocardiogram (ECG)
• Echocardiography

The following retrospective data from the medical file will be analyzed:

• assessment of medical history, medical treatment, and demographic data
• assessment of laboratory results (and, if applicable, other exams) extracted from the medical file and previously performed in the context of polyneuropathy workup
• assessment of previously performed NCV/EMG data and Sudoscan®, extracted from the medical file of the participants.

Inclusion Criteria:

• Patients with chronic axonal length-dependent polyneuropathy (CAP) and/or small-fiber neuropathy (SFN) without well-defined etiology.
• Age: >= 60 years
• Male and female gender
• Written informed consent

Exclusion Criteria:

• Known cause of polyneuropathy
• Other types of peripheral neuropathy than chronic axonal length-dependent polyneuropathy (CAP) and/or small-fiber neuropathy (SFN).
• Patients younger than 60 years