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Recruiting Phase 1 Interventional

The HALT Biomarker Study

ClinicalTrials.gov ID: NCT04552275

Public ClinicalTrials.gov record NCT04552275. Field values are reproduced from the official study page; the official ClinicalTrials.gov record remains the source of truth for eligibility, enrollment, and contact information.

ClinicalTrials.gov public records Last synced Sep 10, 2026, 9:21 PM EDT

Data is sourced from official ClinicalTrials.gov public API records. Always review the official ClinicalTrials.gov record for the latest information.

Official title

Circulating Biomarkers of Hypo-Attenuated Leaflet Thickening After Transcatheter Aortic Valve Replacement

Brief summary

Reproduced verbatim from the official ClinicalTrials.gov record. Not medical advice.

The purpose of the HALT Biomarkers study are to identify a panel of circulating proteins that discriminates between patients with and without Hypo-Attenuated Leaflet Thickening (HALT) and can be used to supplement the diagnosis of HALT; to characterize changes in circulating proteins after treatment of HALT with systemic anticoagulation; and to identify circulating proteins that predict the occurrence of HALT. The study population will be adult patients undergoing transfemoral transcatheter aortic valve replacement (TAVR) for severe aortic stenosis (AS) or bioprosthetic valve degeneration. Enrollment will continue until 30 patients with HALT are identified for completion of phase 1. Based on a HALT incidence rate of 10%, we anticipate enrolling 300 patients. Patients are enrolled prior to undergoing transfemoral TAVR. Blood samples, clinical data and echocardiograms will be collected at the following timepoints: baseline (pre-TAVR, T0), post-TAVR (pre-discharge, T1), 30-day follow-up (window 3-9 weeks, T2), and 6-month follow-up (T3). Cardiac 4D CT will be performed at the 30-day follow-up visit to screen for the occurrence of HALT. Patients with HALT will be treated with systemic anticoagulation for 5-6 months, at which point a follow-up CT scan and blood sample will be obtained. Control subjects will also undergo a 6-month study visit with blood sample collection. The study will be conducted within two phases. Phase 1 will serve as a derivation / discovery study in which candidate protein biomarkers of HALT will be identified. Once this is successfully completed, a second cohort will be enrolled within phase 2. Phase 2 will be performed under the auspices a future contract or amendment and will seek to cross-validate the initial study findings.

Study identification

NCT ID
NCT04552275
Recruitment status
Recruiting
Study type
Interventional
Phase
Phase 1
Enrollment
300 participants

Conditions and interventions

Eligibility (public fields only)

Age range
65 Years and older
Sex
All
Healthy volunteers
Healthy volunteers not accepted

This page does not interpret eligibility. Detailed inclusion and exclusion criteria are on the official ClinicalTrials.gov record.

Study timeline

Start date
Jun 21, 2020
Primary completion
Jun 21, 2030
Completion
Jun 21, 2035
Last update posted
Nov 9, 2021

2020 – 2035

United States locations

U.S. sites
3
U.S. states
3
U.S. cities
3
Facility City State ZIP Site status
Massachusetts General Hospital Boston Massachusetts 02114 Recruiting
Minneapolis Heart Institute Minneapolis Minnesota 55407 Not yet recruiting
Catholic Medical Center Manchester New Hampshire 03103 Recruiting

Site contact phone numbers, emails, and investigator names are intentionally not displayed here. Open the official ClinicalTrials.gov record for site contact information.

About this trial record page

What this page shows
Public field values for ClinicalTrials.gov record NCT04552275, including study identification, conditions, interventions, eligibility (age, sex, healthy volunteer), timeline, and U.S. site list.
What this page does not do
No medical advice, eligibility judgments, treatment recommendations, study quality scoring, or AI-generated medical summaries. No site contact phone numbers, emails, or investigator names.
Where the data comes from
Sourced from the official ClinicalTrials.gov public API. The official record is the source of truth.
Last refresh
Last update posted Nov 9, 2021 · Synced Sep 10, 2026

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Open the official record

The complete protocol, eligibility criteria, and contact information for NCT04552275 live on ClinicalTrials.gov.

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