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- Drawing data from the Swedish National Airway Register, this retrospective cohort study compared the number and severity of acute exacerbations of chronic obstructive pulmonary disease (AECOPD) with subsequent incidence of myocardial infarction (MI) and pulmonary embolism (PE). Reviewing data from more than 66,422 patients with COPD followed for a total duration exceeding 265,000 patient-years, the authors found that the number and severity of AECOPD correlated with an increased long-term risk of both MI and PE.
- The immediate association between AECOPD and PE/MI is well-established, but there was less evidence connecting these conditions over longer periods of time. The authors advocate that additional evaluation is needed for cardiovascular prevention strategies among patients who experience frequent AECOPD.
ABSTRACT 
Background
Acute exacerbations of COPD (AECOPDs) are increasingly recognized as episodes of heightened risk of cardiovascular events. It is not known whether exacerbation history is differentially associated with future myocardial infarction (MI) or pulmonary embolism (PE).
Research Question
Is the number and severity of AECOPDs associated with increased risk of MI or PE in a real-life cohort of patients with COPD?
Study Design and Methods
We identified a cohort of 66422 patients (≥30yr) with a primary diagnosis of COPD in the Swedish National Airway Register January 2014 to June 2022, with complete data on lung function. Patients were classified by moderate (prescription of oral corticosteroids) and severe (hospitalization) exacerbations the year before index date and were followed until Dec 2022 for hospitalization or death from MI or PE, corresponding to >265 000 patient-years, with a maximum follow-up time of 9 years. Competing-risk regression, according to Fine-Gray, was used to calculate subdistribution hazard ratios (SHRs) with 95% confidence intervals (CI).
Results
Compared with no AECOPDs in the baseline period, AECOPD number and severity was associated with increased long term risk of both MI and PE in a gradual fashion, ranging from a SHR of 1.10 (0.97-1.24) and 1.33 (1.11-1.60), respectively, for one moderate exacerbation, to 1.82 (1.36-2.44) and 2.62 (1.77-3.89), respectively, for two or more severe exacerbations. In a time-restricted follow-up sensitivity analysis, the associations were stronger during the first year of follow up and diminished over time.
Interpretation
The risk of MI and PE increases with the frequency and severity of AECOPD in this large real life cohort of patients with COPD.
