LAUSR

Objectives Patients with asthma–chronic obstructive pulmonary disease (COPD) overlap syndrome (ACOS) and cardiovascular diseases (CVDs) share common risk factors. However, the association between ACOS and the incidence of CVDs has not been reported. This study investigated the relationship between CVDs and ACOS in the general population. Setting Data were obtained from Taiwan’s National Health Insurance Research Database for the period 2000 to 2010. Participants The ACOS cohort comprised patients (n=5814) who had received a diagnosis of asthma and COPD. The non-ACOS cohort comprised patients who had not received a diagnosis of asthma or COPD and were matched to the ACOS cohort (2:1) by age, sex and index date (n=11 625). Primary and secondary outcome measures The cumulative incidence of CVDs—coronary artery disease (CAD), cardiac dysrhythmia (CD) and heart failure (HF)—was calculated. Cox proportional regression analysis was employed to examine the relationship between ACOS and CVDs. Results After adjustment for multiple confounding factors—age, sex, comorbidities and medications—patients with ACOS were associated with a significantly higher risk of CVDs; the adjusted HRs (aHRs; 95% CI) for CAD, CD and HF were 1.62 (1.50 to 1.76), 1.44 (1.30 to 1.61) and 1.94 (1.73 to 2.19), respectively, whereas those of beta-blockers treatment for CAD, CD and HF were 1.19 (0.92 to 1.53), 0.90 (0.56 to 1.45) and 0.82 (0.49 to 1.38). The aHR of atenolol treatment for CD was 1.72 (1.01 to 2.93). The aHRs (95% CIs) of ACOS without acute exacerbation of COPD (AE-COPD) for CAD, CD and HF were 1.85 (1.70 to 2.01), 1.57 (1.40 to 1.77) and 2.07 (1.82 to 2.35), respectively. Conclusion ACOS was associated with higher CVD risk, even without the presence of previous comorbidities or AE-COPD. No significant differences in CVD events were observed in the ACOS cohort using beta-blockers, except for those using atenolol for treating CD.