Prevalence of microspirometry-detected chronic obstructive pulmonary disease in two European cohorts of patients hospitalised for acute myocardial infarction: a cross-sectional study

Objectives To establish the prevalence of clinically significant chronic obstructive pulmonary disease (COPD) and relevant characteristics in individuals with a significant smoking history who are hospitalised for acute myocardial infarction (MI). Design Cross-sectional study. Setting Hospital inpatients at 8 European centres (7 in Sweden, 1 in the UK). Participants 518 men or women (302 in Sweden, 216 in the UK) hospitalised for acute MI, aged 40 years or older, with a smoking history of at least 10 pack-years. Primary and secondary outcome measures The primary outcome was prevalence of detected significant COPD (Global Initiative for Chronic Obstructive Lung Disease stages 2–4), defined as a ratio of forced expiratory volume in 1 and 6 s (FEV1/FEV6) <0.7 and FEV1 <80% of the predicted value, measured using microspirometry. Secondary outcome measures were prior diagnosis of COPD, prescription of inhaled corticosteroids (ICS), symptom burden (COPD Assessment Test (CAT)) and blood eosinophil count. Results The prevalence of significant COPD was 91/518 (18% (95% CI 14 to 21)) with no difference between the countries. Of those with detected significant COPD, 69 (76%) had no previous COPD diagnosis. A CAT score >10 was found in 65%, and a blood eosinophil count of ≥100/mm3 and ≥300/mm3 was found in 76% and 20%, respectively. Inhaled corticosteroids were used by 15% of the patients. Conclusions In a cohort of patients hospitalised for acute MI in Sweden and the UK, one in five patients with a history of smoking was found to have significant COPD based on microspirometry. Symptom burden was high and treatment rates with ICS low. Among those diagnosed with COPD, three out of four had not been previously diagnosed with COPD.