Using Indoor Air Filtration to Slow Atherothrombosis Progression in Adults With Ischemic Heart Disease History

NCT ID: NCT05867381

Last Updated: 2025-08-01

Study Results

Results pending

The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.

Basic Information

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Recruitment Status

RECRUITING

Clinical Phase

NA

Total Enrollment

112 participants

Study Classification

INTERVENTIONAL

Study Start Date

2023-07-11

Study Completion Date

2027-06-30

Brief Summary

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This double-blind, randomized, crossover trial aims to test the hypothesis that longer-term indoor air filtration intervention can slow atherothrombosis progression by reducing indoor fine particulate matter (PM2.5) exposure in adults with ischemic heart disease history.

Detailed Description

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This double-blind, randomized, crossover trial will recruit 112 adults with ischemic heart disease history and will investigate potential benefits of indoor high efficiency particulate air (HEPA) filtration on ameliorating the progression of atherothrombosis. Participants will be contacted and recruited to the study based on inclusion and exclusion criteria. After consenting, participants will go through a total of 21-month study period comprised of true HEPA filtration and sham filtration, each of 9-month in duration, and a 3-month wash-out period. After 3-month wash-out period, participants will be switched to the other arm of the intervention. During the trial, project specialists will complete a series of home visits before, in the middle, and after each intervention session to set up air purifiers and indoor and outdoor air pollution monitors, as well as conduct interview to collect questionnaire data, measure vascular function, blood pressure, and collect biospecimens. Participants will self-monitor their daily blood pressure through out the intervention periods. In aim 1, researchers will assess the effect of a 9-month residential HEPA intervention on atherothrombosis progression in 112 participants. In aim 2, the researchers will examine the association between reduction in indoor PM2.5 exposure brought by the intervention and the changes in atherothrombosis progression indicators adjusting for outdoor PM2.5 exposure. In aim 3, researchers will examine atherothrombosis responses (both levels and slopes of change) to the HEPA intervention within four subgroups of participants: 1) non-Hispanics, 2) Hispanics, 3) females, and 4) males.

Conditions

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Air Pollution Atherosclerosis

Study Design

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Allocation Method

RANDOMIZED

Intervention Model

CROSSOVER

Primary Study Purpose

PREVENTION

Blinding Strategy

DOUBLE

Participants Investigators
A sham filter will be used in the control, to replace HEPA filter in the intervention group. Participants and investigators will be blinded to the intervention type, only investigators who will prepare air filters for intervention will be unblinded for the real air filter type.

Study Groups

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HEPA first and sham

This group of participants will be assigned to the intervention of HEPA filtration with the capacity to reduce indoor PM2.5 levels at their residence for 9 months first. After 3-month wash-out period, participants will be assigned to sham filters (air purifier has the same appearance but HEPA filter is removed) for 9 months.

Group Type EXPERIMENTAL

HEPA filtration

Intervention Type DEVICE

HEPA filters with the capacity to reduce PM2.5 levels

Sham filtration

Intervention Type DEVICE

Sham filtration use the same appearance of air purifier but with HEPA filter removed.

Sham first and HEPA

This group of participants will be assigned to the intervention of sham filtration with HEPA filter removed at their residence for 9 months first. After 3-month wash-out period, participants will be assigned to the HEPA filtration for 9 months.

Group Type EXPERIMENTAL

HEPA filtration

Intervention Type DEVICE

HEPA filters with the capacity to reduce PM2.5 levels

Sham filtration

Intervention Type DEVICE

Sham filtration use the same appearance of air purifier but with HEPA filter removed.

Interventions

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HEPA filtration

HEPA filters with the capacity to reduce PM2.5 levels

Intervention Type DEVICE

Sham filtration

Sham filtration use the same appearance of air purifier but with HEPA filter removed.

Intervention Type DEVICE

Eligibility Criteria

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Inclusion Criteria

* Age between 65 and 84 years old;
* Weight ≥ 110 pounds;
* Nonsmokers for at least 1 year;
* Have ischemic heart disease history, clinically stable for 6 months, without any deterioration in symptoms or episodes of angina based on past electronic medical records;
* Both English and Spanish speaking participants will be included in the recruitment;
* Live in the Los Angeles County.

Exclusion Criteria

* Have history of degenerative disease of the nervous system such as dementia and Alzheimer's;
* Currently have active cancer treatments;
* The residential house has already had HEPA filters;
* Participants will move out from the current residential address in the next 2 years;
* Participants will spend more than 1 month living outside the primary home;
* Have any health conditions that prohibit collecting health and covariate data and biospecimens;
* Participants' residential houses are not feasible for setting up air purifiers and air pollutants monitors.
Minimum Eligible Age

65 Years

Maximum Eligible Age

84 Years

Eligible Sex

ALL

Accepts Healthy Volunteers

No

Sponsors

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Duke University

OTHER

Sponsor Role collaborator

National Institute of Environmental Health Sciences (NIEHS)

NIH

Sponsor Role collaborator

University of Southern California

OTHER

Sponsor Role lead

Responsible Party

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Zhanghua Chen

Assistant Professor

Responsibility Role PRINCIPAL_INVESTIGATOR

Principal Investigators

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Zhanghua Chen, PhD

Role: PRINCIPAL_INVESTIGATOR

University of Southern California

Junfeng Zhang, PhD

Role: PRINCIPAL_INVESTIGATOR

Duke University

Locations

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Keck School of Medicine, University of Southern California

Los Angeles, California, United States

Site Status RECRUITING

Countries

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United States

Central Contacts

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Zhanghua Chen, PhD

Role: CONTACT

323-442-2109

Junfeng Zhang, PhD

Role: CONTACT

919-681-7782

Facility Contacts

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Zhanghua Chen, PhD

Role: primary

323-442-2109

Other Identifiers

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R01ES033707

Identifier Type: NIH

Identifier Source: secondary_id

View Link

SAPIA_Study

Identifier Type: -

Identifier Source: org_study_id

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