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

July 17, 2025 updated by: Veronique Bissay, Universitair Ziekenhuis Brussel

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).

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

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.

Study Type

Interventional

Enrollment (Estimated)

150

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

  • Belgium
    • Belgium Capital City
      • Jette, Belgium Capital City, Belgium, 1090
        • Recruiting
        • UZ Brussel
        • Contact:
        • Contact:
        • Principal Investigator:
          • Véronique Bissay, MD, Phd
        • Sub-Investigator:
          • Steven Droogmans, MD, Phd

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

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

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Screening
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Other: 1 arm including patients with CAP and/or SFN

1 arm including patients with chronic axonal length-dependent polyneuropathy and/or small-fiber neuropathy.

All participants will be screened with ECG and echocardiography. All participants will be asked to complete questionnaires about there polyneuropathy and cardiological symptoms.
Diagnostic test: ECG + echocardiography
Electrocardiogram and echocardiography
Other: Answering questionnaires
Answering questionnaires about polyneuropathy symptoms (NTSS -6, COMPASS31, NIS, mPND) and also cardialogical symptoms (KCCQ-12).

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Primary Outcome: Evaluation of prevalence of wild-type cardiac amyloidosis in our CAP and/or SFN population without well known cause.
Time Frame: 36 months

Prevalence of cardiac amyloidosis by doing a cardiac screening for wild-type cardiac amyloidosis with performing an echocardiography.

Echocardiography criteria: LV wall (>12mm), left ventricular ejection fraction (%), Apical sparing pattern (y/n), diastolic dysfunction (y/n), left atrial volume (ml/m2).

Left atrial volume in ml and LA volume in ml/m2, whereby m2 is the body surface area based on weight and height (Mosteller formula).
36 months
Primary Outcome: Evaluation of prevalence of wild-type cardiac amyloidosis in our CAP and/or SFN population without well known cause
Time Frame: 36 months

Prevalence of cardiac amyloidosis by doing a cardiac screening for wild-type cardiac amyloidosis with performing an ECG.

ECG criteria: atrial fibrillation (y/n), QRS-duration, low voltage (y/n)
36 months
Primary Outcome: Evaluation of prevalence of wild-type cardiac amyloidosis in our CAP and/or SFN population without well known cause
Time Frame: 36 months

Prevalence of cardiac amyloidosis by doing a cardiac screening for wild-type cardiac amyloidosis with performing a questionnaire (Kansas City Cardiomyopathy Questionnaire).

KCCQ-12 has 4 domains (Physical Limitation Score, Symptom Frequency Score, Quality of Life Score, Social Limitation Score) and one Summary Score. Scores are scaled 0-100, where 0 denotes the lowest reportable health status and 100 the highest.

This descriptive score will be used as a functional parameter without a cut-off.
36 months

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Secondary outcome: severity and evolution
Time Frame: 36 months
Considering the rather small study population and the rarity of wtTTR amyloidosis, statistical analyses cannot be used without massively overfitting the results, which will not be reproducible. The investigators consequently opt for descriptive statistics to compare the group of polyneuropathy patients with wt-Ca and those without wt-CA. Therefore a few parameters are examined. The first scale used therefore is the modified Polyneuropathy Disability score (mPND). This scale is a questionnaire with a few questions about the complaints of the polyneuropathy in the daily life. O means no complaints of the polyneuropathy in daily life, IV means a major impact on the daily life of the patient.
36 months
Secondary outcome: severity and evolution
Time Frame: 36 months

Considering the rather small study population and the rarity of wtTTR amyloidosis, statistical analyses cannot be used without massively overfitting the results, which will not be reproducible.

The investigators consequently opt for descriptive statistics to compare the group of polyneuropathy patients with wt-Ca and those without wt-CA. Therefore a few parameters are examined. The second scale used therefore is the Neuropathy Impairment Score (NIS).This scale is a questionnaire with a few questions about the complaints of the polyneuropathy in the daily life. The score is between 0 and 244. O means less complaints in the daily life, 244 means major impact in the daily life of the patient.
36 months
Secondary outcome: severity and evolution
Time Frame: 36 months

Considering the rather small study population and the rarity of wtTTR amyloidosis, statistical analyses cannot be used without massively overfitting the results, which will not be reproducible.

The investigators consequently opt for descriptive statistics to compare the group of polyneuropathy patients with wt-Ca and those without wt-CA. Therefore a few parameters are examined. The third scale used therefore is the Neuropathy Total Symptom Score - Health Care professional administered version (NTSS-6). This scale is a questionnaire with a few items about the symptoms of the polyneuropathy in the daily life (aching pain, burning pain, prickling sensation, numbness, lancinating pain and allodynia). Depending on the presence of the symptoms in time and strength, a score will show up. On each symptom you can score a maximum of 3,66. So the total score for this scale is 21,96 if the patients has major complaints in daily life.
36 months
Secondary outcome: severity and evolution
Time Frame: 36 months

Considering the rather small study population and the rarity of wtTTR amyloidosis, statistical analyses cannot be used without massively overfitting the results, which will not be reproducible.

The investigators consequently opt for descriptive statistics to compare the group of polyneuropathy patients with wt-Ca and those without wt-CA. Therefore a few parameters are examined. The fourth scale used therefore is the Composite Autonomic Symptom score (COMPASS-31). This scale is a questionnaire with a 31 questions about the complaints in the daily life and also if there complaints/symptoms on the autonomic system. A few questions are asked about different domains (orthostatic intolerance, vasomotor, secretomotor, gastrointestinal system, bladder, pupillomotor).The total score is minimal 0 and maximal 75 raw counted (100 weighted).Each domain had a weighting factor to be count depending on the answers of the patient.
36 months
Secondary outcome: red flags that could increase the awareness of neurologists for wild-type TTR-cardiac amyloidosis
Time Frame: 36 months
The red flags for wild-type TTR cardiac amyloidosis are among others carpal tunnel syndrome (CTS), wich can be detected by performing an electromyography (EMG).
36 months
Secondary outcome: red flags that could increase the awareness of neurologists for wild-type TTR-cardiac amyloidosis
Time Frame: 36 months
The red flags for wild-type TTR cardiac amyloidosis are among others spinal canal stenosis.
36 months
Secondary outcome: red flags that could increase the awareness of neurologists for wild-type TTR-cardiac amyloidosis
Time Frame: 36 months
The red flags for wild-type TTR cardiac amyloidosis are among others trigger finger.
36 months

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Universitair Ziekenhuis Brussel

Investigators

  • Principal Investigator: Veronique Bissay, MD, Phd, UZ Brussel - VUB

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

July 28, 2023

Primary Completion (Estimated)

June 1, 2026

Study Completion (Estimated)

June 1, 2026

Study Registration Dates

First Submitted

April 21, 2023

First Submitted That Met QC Criteria

July 14, 2023

First Posted (Actual)

July 18, 2023

Study Record Updates

Last Update Posted (Actual)

July 22, 2025

Last Update Submitted That Met QC Criteria

July 17, 2025

Last Verified

July 1, 2025

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • EC-2023-115

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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