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

University of Southern California

Status: Enrolling

Conditions: Air Pollution; Atherosclerosis

Treatments: Device: HEPA filtration; Device: Sham filtration

Study type: Interventional

Funder types: Other; NIH

Identifiers

NCT05867381

SAPIA_Study

R01ES033707 (U.S. NIH Grant/Contract)

Details and patient eligibility

About

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.

Full description

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.

Enrollment: 112 estimated patients

Sex: All

Ages: 65 to 84 years old

Volunteers: No Healthy Volunteers

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.

Trial design

Primary purpose: Prevention

Allocation: Randomized

Interventional model: Crossover Assignment

Masking: Double Blind

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112 participants in 2 patient groups

HEPA first and sham

Experimental group

Description:

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.

Treatment:

Device: Sham filtration

Device: HEPA filtration

Sham first and HEPA

Experimental group

Description:

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.

Treatment:

Device: Sham filtration

Device: HEPA filtration