Effects of reducing exposure to air pollution on submaximal cardiopulmonary test in patients with heart failure: Analysis of the randomized, double-blind and controlled FILTER-HF trial.
BACKGROUND
Air pollution exposure could mitigate the health benefits of exercise in patients with heart failure (HF). We tested the effects of a respiratory filter on HF patients exposed to air pollution during exercise.


RESULTS
Ancillary analysis of the FILTER-HF trial, focused on the exercise outcomes. In a randomized, double-blind, 3-way crossover design, 26 HF patients and 15 control volunteers were exposed to clean air, unfiltered dilute diesel engine exhaust (DE), or filtered DE for 6min during a submaximal cardiopulmonary testing in a controlled-exposure facility. Prospectively collected data included six-minute walking test [6mwt], VO2, VE/VCO2 Slope, O2Pulse, pulmonary ventilation [VE], tidal volume, VD/Vt, oxyhemoglobin saturation and CO2-rebreathing. Compared to clean air, DE adversely affected VO2 (11.0±3.9 vs. 8.4±2.8ml/kg/min; p<0.001); 6mwt (243.3±13.0 vs. 220.8±13.7m; p=0.030); and O2Pulse (8.9±1.0 vs. 7.8±0.7ml/beat; p<0.001) in HF patients. Compared to DE, filtration reduced the particulate concentration from 325±31 to 25±6μg/m(3), and was associated with an increase in VO2 (10.4±3.8ml/kg/min; p<0.001 vs. DE) and O2Pulse (9.7±1.1ml/beat; p<0.001 vs. DE) in patients with HF. Filtration was associated with higher VE and CO2-rebreathing in both groups. VE/VCO2 Slope was higher among patients with HF.


CONCLUSIONS
DE adversely affects exercise capacity in patients with HF. A simple respiratory filter can reduce the adverse effects of pollution on VO2 and O2Pulse. Given the worldwide prevalence of exposure to traffic-related air pollution, these findings are relevant for public health especially in this highly susceptible population. The filter intervention holds great promise that needs to be tested in future studies.
Heart Failure Department, Heart Institute (InCor), University of Sao Paulo Medical School, Sao Paulo, Brazil. Electronic address: jefvieira@yahoo.com.br.
Jefferson L
JL
Vieira
Heart Failure Department, Heart Institute (InCor), University of Sao Paulo Medical School, Sao Paulo, Brazil.
Guilherme V
GV
Guimaraes
Air Pollution Laboratory, University of Sao Paulo Medical School, Sao Paulo, Brazil.
Paulo A
PA
de Andre
Air Pollution Laboratory, University of Sao Paulo Medical School, Sao Paulo, Brazil.
Paulo H Nascimento
PH
Saldiva
Heart Failure Department, Heart Institute (InCor), University of Sao Paulo Medical School, Sao Paulo, Brazil.
Edimar A
EA
Bocchi
D000328:Adult; D000397:Air Pollution / Q000009:adverse effects*; D018592:Cross-Over Studies; D004311:Double-Blind Method; D005080:Exercise Test / Q000379:methods*; D005260:Female; D006333:Heart Failure / Q000175:diagnosis / Q000503:physiopathology*; D006801:Humans; D019570:Inhalation Exposure / Q000009:adverse effects; D008297:Male; D008875:Middle Aged; D010101:Oxygen Consumption / Q000502:physiology; D012123:Pulmonary Ventilation / Q000502:physiology; D012134:Respiratory Protective Devices; D001335:Vehicle Emissions
D001335:Vehicle Emissions
Air pollution; Exercise; Heart failure