Abstract 12234: Effects of Reducing Exposure to Air Pollution With a Filter on Exercise: A Randomized, Prospective, Double-Blind, Controlled Study of Heart Failure
Background: The benefits of respiratory filters on patients with heart failure (HF) exposed to air pollution during daily activities have not been established.
Methods: We tested the short-term effects of a filter intervention (FILTER) in a double-blind,randomized and 3-way crossover study with 30 HF patients and 15 control volunteers exposed, in three separate sessions, to clean air, dilute diesel exhaust (DE) or filtered DE. Pre-specified endpoints included variation in exercise tolerance (six-minute walking test [6mwt meters]; systemic blood pressure [BP mmHg], heart rate [HR bpm] and respiratory rate [RR rpm] responses) and gas-exchange variables (oxygen uptake [VO2 ml/kg/min]; oxygen saturation [Sat.O2 %]; ventilation and carbon dioxide production ratio [VE/VCO2 slope]; oxygen uptake per heart beat [O2Pulse ml/beat]; pulmonary ventilation [VE l/min]; tidal volume [Vt ml]; functional estimate of dead space [VD/Vt]) during a submaximal test.
Results: In HF patients, DE adversely affected VO2 (11.0±3.9 vs. 8.4±2.8 ml/Kg/min; p < 0.001) (figure), 6mwt (243.3±13.0 vs. 220.8±13.7 m; p = 0.030), and O2Pulse (8.9±1.0 vs. 7.8±0.7 ml/beat; p < 0.001). When compared to DE-protocol, the FILTER reduced the particulate concentration from 325±31 to 25±6 μg/m3 (p < 0.001), and in HF patients it was associated with an increase in VO2 (10.4±3.8 ml/Kg/min; p < 0.001) (figure) and O2Pulse (9.7±1.1 ml/beat; p < 0.001). FILTER was also associated, in HF and control groups, with significantly higher pulmonary ventilation, tidal volumes, functional estimate of dead space and CO2 exchange. Other variables as VE/VCO2 slope, HR, BP and RR did not differ between exposure protocols.
Conclusion: Air pollution adversely affects exercise tolerance in HF patients. FILTER can reduce the particulate concentration during DE-exposure, preventing pollution-effects on VO2 and O2Pulse.
Author Disclosures: J.L. Vieira: None. G.V. Guimaraes: None. P.A. de Andre: None. P.H. Saldiva: None. E.A. Bocchi: Research Grant; Modest; Servier. Speakers Bureau; Modest; Novartis, Baldacci, Servier. Honoraria; Modest; Astra-Zeneca. Consultant/Advisory Board; Modest; Novartis.
- © 2015 by American Heart Association, Inc.