Exposure to respirable desert dust entering indoors prompts quick oxidative-stress and inflammatory responses in the airways of chronic heart failure patients.

A significant portion of the population is exposed to airborne PM levels exceeding WHO guidelines, particularly during desert dust events, which are increasing due to climate change. Cardiovascular mortality has been linked to PM exposure, but most studies rely on outdoor air quality data that may not reflect indoor exposure. This study, DESERT HEART, examines whether indoor PM exposure during dust events influences airway inflammation and oxidative stress in 40 patients with stable chronic heart failure (HF). Sputum samples were collected weekly for three weeks, and biomarkers (IL-8, MDA, MMP-9, TGF-ß1, CRP) were analyzed. Indoor PM levels were monitored at patients' homes. Mixed regression models assessed the impact of PM ≥ 90 µg/m on biomarkers. Analysis of 120 sputum samples and 720 days of air quality data showed that exposure significantly increased biomarker levels on the first day: IL-8 (+ 6.9 ng/gwt, p = 0.032), MDA (+ 1.3 nmol/gwt, p = 0.014), MMP-9 (+ 222.4 ng/gwt, p = 0.09), TGF-ß1 (+ 4.1 ng/gwt, p = 0.058), and CRP (+ 2 ng/gwt, p = 0.02), followed by a sharp decline. These findings suggest that indoor PM exposure from desert dust events acutely exacerbates airway inflammation and oxidative stress in HF patients, highlighting the need for targeted interventions.