Increased risk of myocardial infarction and stroke following exacerbation of COPD

Patients with COPD are at risk for cardiovascular events. This is attributed to increased systemic inflammation. The course of COPD is punctuated by exacerbations, which further increase systemic inflammation, but the risk of vascular events in the postexacerbation period has never been defined.

We analyzed data from 25,857 patients with COPD entered in The Health Improvement Network database over a 2-year period. Exacerbations were defined using a health-care use definition of prescription of oral corticosteroids > 20 mg/d and/or selected oral antibiotics. The risk of myocardial infarction (MI) and stroke in the postexacerbation period was calculated relative to the patient's baseline risk using the self-controlled case series approach.

We identified 524 MIs in 426 patients and 633 ischemic strokes in 482 patients. The incidence rates of MI and stroke were 1.1 and 1.4 per 100 patient-years, respectively. There was a 2.27-fold (95% CI, 1.1-4.7; P = .03) increased risk of MI 1 to 5 days after exacerbation (defined by prescription of both steroids and antibiotics). This relative risk diminished progressively with time and was not significantly different from the baseline MI risk at any other postexacerbation time interval. One in 2,513 exacerbations was associated with MI within 1 to 5 days. There was a 1.26-fold (95% CI, 1.0-1.6; P = .05) increased risk of stroke 1 to 49 days after exacerbation.

The results suggest that exacerbations of COPD increase the risk of MI and stroke. This may have implications for therapy in both stable and exacerbated COPD.