Author + information
- Received April 28, 2015
- Revision received July 15, 2015
- Accepted July 17, 2015
- Published online January 1, 2016.
- Jefferson L. Vieira, MD∗∗ (, )
- Guilherme V. Guimaraes, PhD∗,
- Paulo A. de Andre, PhD†,
- Fátima D. Cruz, RN∗,
- Paulo H. Nascimento Saldiva, MD, PhD† and
- Edimar A. Bocchi, MD, PhD∗
- ∗Heart Institute (InCor), University of São Paulo Medical School, São Paulo, Brazil
- †Air Pollution Laboratory, University of São Paulo Medical School, São Paulo, Brazil
- ↵∗Reprint requests and correspondence:
Dr. Jefferson L. Vieira, Avenida Doutor Enéas de Carvalho Aguiar, 44–Cerqueira Cesar, São Paulo, SP 05403-900, Brazil.
Objectives 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/m3 vs. 25 ± 6 μg/m3; 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)
This study was supported by FAPESP (Fundação de Amparo a Pesquisa do Estado de São Paulo, 2010/50150-0). The authors have reported that they have no relationships relevant to the contents of this paper to disclose.
- Received April 28, 2015.
- Revision received July 15, 2015.
- Accepted July 17, 2015.
- American College of Cardiology Foundation