BMJ Open Respir Res. 2017 Apr 5;4(1):e000164. doi: 10.1136/bmjresp-2016-000164. eCollection 2017
INTRODUCTION: β Blockers are important treatment for ischaemic heart disease and
heart failure; however, there has long been concern about their use in people
with chronic obstructive pulmonary disease (COPD) due to fear of symptomatic
worsening of breathlessness. Despite growing evidence of safety and efficacy,
they remain underused. We examined the effect of β-blockade on lung function,
exercise performance and dynamic hyperinflation in a group of vascular surgical
patients, a high proportion of who were expected to have COPD.
METHODS: People undergoing routine abdominal aortic aneurysm (AAA) surveillance
were sequentially recruited from vascular surgery clinic. They completed
plethysmographically measured lung function and incremental cardiopulmonary
exercise testing with dynamic measurement of inspiratory capacity while taking
and not taking β blocker.
RESULTS: 48 participants completed tests while taking and not taking β blockers
with 38 completing all assessments successfully. 15 participants (39%) were found
to have, predominantly mild and undiagnosed, COPD. People with COPD had airflow
obstruction, increased airway resistance (Raw) and specific conductance (sGaw),
static hyperinflation and dynamically hyperinflated during exercise. In the whole
group, β-blockade led to a small fall in FEV1 (0.1 L/2.8% predicted) but did not
affect Raw, sGaw, static or dynamic hyperinflation. No difference in response to
β-blockade was seen in those with and without COPD.
CONCLUSIONS: In people with AAA, β-blockade has little effect on lung function
and dynamic hyperinflation in those with and without COPD. In this population,
the prevalence of COPD is high and consideration should be given to case finding
TRIAL REGISTRATION NUMBER: NCT02106286.