HypertensionRandomised controlled trial
Effect of High-efficiency Particulate Arrestance (HEPA) Filtration Air Purifiers on Blood Pressure
- Randomised crossover trial
- pragmatic
- sham-controlled
Authors' conclusion
The use of in-home HEPA air purifiers resulted in clinically important reductions in SBP for people with elevated SBP in environments with relatively low PM2.5 concentrations.
Study context
- Population
- Adults living adjacent to highwaysanalysed
- Participants
- 154 adults
- Comparison
- HEPA filtration vs sham filtration
- Primary endpoint
- Mean change in BP between HEPA and sham filtration periods
- Follow-up
- 1 month
Primary result
Change in SBP, elevated SBP (≥120 mm Hg)
Mean difference
3.0 mm Hg
P = 0.04
By group
HEPA
2.8
mean reduction · mm Hg
Sham
0.2
mean increase · mm Hg
As reported in the abstract
- Baseline systolic blood pressure (SBP) moderated the efficacy of the intervention
- P = 0.03
Further findings
Diastolic blood pressure (BP); SBP in participants with normal SBP (<120 mm Hg)
- No significant benefit
Particulate matter (PM) concentrations (subset of residences)
- HEPA significantly reduced PM vs indoor sham and outdoor levels
Original publication
Effect of HEPA Filtration Air Purifiers on Blood Pressure. J Am Coll Cardiol. Published 6 August 2025. doi:10.1016/j.jacc.2025.06.037
Summarised from the published abstract; every number is checked against it