Serial pulmonary function tests to diagnose COPD in chronic heart failure.

BACKGROUND: It is unknown whether serial pulmonary function tests are necessary for the correct diagnosis of chronic obstructive pulmonary disease (COPD) in patients with stable non-congested chronic heart failure (CHF). The aim of this study was to determine the prevalence of COPD in outpatients with stable CHF without pulmonary congestion using initial as well as confirmatory spirometry three months after treatment for COPD.

METHODS: Spirometry was performed in 187 outpatients with stable CHF without pulmonary congestion on chest radiograph who had a left ventricular ejection fraction < 40% (mean age 69 ± 10 years, 78% men). COPD was defined according to the Global Initiative for Chronic Obstructive Lung Disease guidelines. The diagnosis of COPD was confirmed three months after treatment with tiotropium in newly diagnosed COPD patients.

RESULTS: Using a three month follow-up spirometry to confirm initial diagnosis of de novo COPD did not change COPD prevalence significantly: 32.6% initially versus 32.1% after three months of follow-up. Only 1 of 25 (4%) patients with newly diagnosed COPD was not reproducibly obstructed at follow-up. COPD was greatly under- (19%) and overdiagnosed (32%).

CONCLUSIONS: Spirometry should be used under stable and euvolemic conditions to decrease the burden of undiagnosed or overdiagnosed COPD in patients with CHF. Under these conditions, a confirmatory spirometry is unnecessary, as it does not change a newly established diagnosis of COPD in the vast majority of patients with CHF.

TRIAL REGISTRATION: ClinicalTrials.gov Identifier NCT01429376.