title: Respiratory Filter Reduces the Cardiovascular Effects Associated With Diesel Exhaust Exposure: A Randomized, Prospective, Double-Blind, Controlled Study of Heart Failure: The FILTER-HF Trial.
abstract: OBJECTIVE
  The goal of this study was to test the effects of a respiratory filter intervention (filter) during controlled pollution exposure.
  
  
  BACKGROUND
  Air pollution is considered a risk factor for heart failure (HF) decompensation and mortality.
  
  
  METHODS
  This study was a double-blind, randomized to order, controlled, 3-way crossover, single-center clinical trial. It enrolled 26 patients with HF and 15 control volunteers. Participants were exposed in 3 separate sessions to clean air, unfiltered diesel exhaust exposure (DE), or filtered DE. Endpoints were endothelial function assessed by using the reactive hyperemia index (RHi), arterial stiffness, serum biomarkers, 6-min walking distance, and heart rate variability.
  
  
  RESULTS
  In patients with HF, DE was associated with a worsening in RHi from 2.17 (interquartile range [IQR]: 1.8 to 2.5) to 1.72 (IQR: 1.5 to 2.2; p = 0.002) and an increase in B-type natriuretic peptide (BNP) from 47.0 pg/ml (IQR: 17.3 to 118.0 pg/ml) to 66.5 pg/ml (IQR: 26.5 to 155.5 pg/ml; p = 0.004). Filtration reduced the particulate concentration (325 ± 31 μg/m(3) vs. 25 ± 6 μg/m(3); p < 0.001); in the group with HF, filter was associated with an improvement in RHi from 1.72 (IQR: 1.5 to 2.2) to 2.06 (IQR: 1.5 to 2.6; p = 0.019) and a decrease in BNP from 66.5 pg/ml (IQR: 26.5 to 155.5 pg/ml) to 44.0 pg/ml (IQR: 20.0 to 110.0 pg/ml; p = 0.015) compared with DE. In both groups, DE decreased the 6-min walking distance and arterial stiffness, although filter did not change these responses. DE had no effect on heart rate variability or exercise testing.
  
  
  CONCLUSIONS
  To our knowledge, this trial is the first to show that a filter can reduce both endothelial dysfunction and BNP increases in patients with HF during DE. Given these potential benefits, the widespread use of filters in patients with HF exposed to traffic-derived air pollution may have beneficial public health effects and reduce the burden of HF. (Effects of Air Pollution Exposure Reduction by Filter Mask on Heart Failure; NCT01960920).
authors.affiliation: Heart Institute (InCor), University of São Paulo Medical School, São Paulo, Brazil. Electronic address: jefvieira@yahoo.com.br.
authors.forename: Jefferson L
authors.initials: JL
authors.lastname: Vieira
authors.affiliation: Heart Institute (InCor), University of São Paulo Medical School, São Paulo, Brazil.
authors.forename: Guilherme V
authors.initials: GV
authors.lastname: Guimaraes
authors.affiliation: Air Pollution Laboratory, University of São Paulo Medical School, São Paulo, Brazil.
authors.forename: Paulo A
authors.initials: PA
authors.lastname: de Andre
authors.affiliation: Heart Institute (InCor), University of São Paulo Medical School, São Paulo, Brazil.
authors.forename: Fátima D
authors.initials: FD
authors.lastname: Cruz
authors.affiliation: Air Pollution Laboratory, University of São Paulo Medical School, São Paulo, Brazil.
authors.forename: Paulo H Nascimento
authors.initials: PH
authors.lastname: Saldiva
authors.affiliation: Heart Institute (InCor), University of São Paulo Medical School, São Paulo, Brazil.
authors.forename: Edimar A
authors.initials: EA
authors.lastname: Bocchi
mesh_terms: D015415:Biomarkers / Q000378:metabolism; D018592:Cross-Over Studies; D004311:Double-Blind Method; D004730:Endothelium, Vascular / Q000502:physiology; D004781:Environmental Exposure / Q000009:adverse effects*; D005080:Exercise Test; D005260:Female; D006333:Heart Failure / Q000503:physiopathology*; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D006940:Hyperemia / Q000209:etiology / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D020097:Natriuretic Peptide, Brain / Q000378:metabolism; D011446:Prospective Studies; D012134:Respiratory Protective Devices; D059289:Vascular Stiffness / Q000502:physiology; D001335:Vehicle Emissions / Q000633:toxicity*; D016138:Walking / Q000502:physiology
chemical_list: D015415:Biomarkers; D001335:Vehicle Emissions; D020097:Natriuretic Peptide, Brain
keywords: air pollution; endothelium; heart failure