Background: Using a fixed ratio of forced expiratory volume in 1 s to forced vital capacity (FEV1/FVC) < 0.70 instead of the lower limit of normal (LLN) to define chronic obstructive pulmonary disease (COPD) may lead to overdiagnosis of COPD in elderly patients with heart failure (HF) and consequently unnecessary treatment with possible adverse health effects.
Objective: The aim of this study was to determine COPD prevalence in patients with chronic HF according to two definitions of airflow obstruction.
Methods: Spirometry was performed in 187 outpatients with stable chronic HF without pulmonary congestion who had a left ventricular ejection fraction <40% (mean age 69 ± 10 years, 78% men). COPD diagnosis was confirmed 3 months after standard treatment with tiotropium in newly diagnosed COPD patients.
Results: COPD prevalence varied substantially between 19.8% (LLN-COPD) and 32.1% (GOLD-COPD). Twenty-three of 60 patients (38.3%) with GOLD-COPD were potentially misclassified as having COPD (FEV1/FVC < 0.7 but > LLN). In contrast to patients with LLN-COPD, potentially misclassified patients did not differ significantly from those without COPD regarding respiratory symptoms and risk factors for COPD.
Conclusions: One fifth, rather than one third, of the patients with chronic HF had concomitant COPD using the LLN instead of the fixed ratio. LLN may identify clinically more important COPD than a fixed ratio of 0.7.
Keywords: ABHR; ACE-I; ARB; ATS/ERS; American Thoracic Society/European Respiratory Society; BMI; CABG; COPD; CRT; CS; Chronic heart failure; Chronic obstructive pulmonary disease; FEV(1)/FVC; FS; Fixed ratio; GOLD; Global Initiative for Chronic Obstructive Lung Disease; HF; ICD; LLN; LVEF; LVSD; Lower limit of normal; MLHFQ; MRC; Minnesota Living with Heart Failure Questionnaire; N-terminal pro-B natriuretic peptide; NS; NT-pro-BNP; NYHA; New York Heart Association; PCI; PFT; PY; Prevalence; angiotensin receptor blocker; angiotensin-converting enzyme inhibitor; aspecific bronchial hyperreactivity; body mass index; cardiac resynchronization therapy; chronic obstructive pulmonary disease; coronary artery bypass grafting; current smokers; former smokers; heart failure; implantable cardioverter defibrillator; left ventricular ejection fraction; left ventricular systolic dysfunction; lower limit of normal; modified Medical Research Council dyspnea scale; non-smokers; pack-years; percutaneous coronary intervention; pulmonary function tests; ratio of forced expiratory volume in 1 s to forced vital capacity.
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