Exposure to air pollution is associated with increase in cardiovascular morbidity and mortality. Controlled human exposure studies have demonstrated impaired vascular function and heart rate variability on healthy volunteers. The aim of this study is to investigate the effects of reducting diesel exhaust inhalation on endothelial function, heart rate variability and cardiopulmonary stress testing in healthy volunteers and patients with chronic heart failure, by using a filter mask.

Design and setting: Double-blind randomised crossover studies in a university teaching hospital

Patients: 30 patients with stable Heart Failure (NYHA I-III) and 15 healthy volunteers

Interventions: All 45 subjects will be exposed to dilute diesel exhaust (PM2.5 of 300 mg/m3), filtered diesel exhaust (filter mask), or filtered air

Main outcome measures: Endothelial function, heart rate variability, six-minute walking test and blood samples for inflammatory factors

Inclusion Criteria:

• NYHA I-III;
• Left Ventricle Ejection Fraction < 50%;
• Clinical condition stable for more than three months prior to the randomization;

Exclusion Criteria:

• Severe arterial hypertension;
• Severe Pulmonary disease;
• Patients with pace-markers;
• Patients with constrictive pericarditis;
• Severe chronic kidney disease;
• Patients with pulmonary hypertension;
• Stroke within the last six months;
• Severe hepatic disease;
• Patients with musculoskeletal limitations to exercise;
• Patients with cardiac cachexia.