A recent study examined the possible association between more frequent exacerbations in chronic obstructive pulmonary disease (COPD) and stroke, finding no evidence for such a link. The report, “No association between exacerbation frequency and stroke in patients with COPD,“ appeared on Feb. 2, 2016, in the International Journal of Chronic Obstructive Pulmonary Disease.
COPD is a group of lung diseases in which airflow is blocked and breathing becomes difficult. People with COPD are at increased risk for stroke, possibly due to the chronic inflammation that is associated with the disease, leading investigators to examine a possible link between the two.
The research team, led by Claire Windsor of the Faculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, utilized a database called the U.K. Clinical Practice Research Datalink to identify COPD patients who had a first stroke between January 2004 and December 2013. The scientists included 6,441 cases, and 19,323 control participants who had COPD but no history of stroke.
The researchers identified frequent exacerbations (FEs), or sudden flares in COPD symptoms, as well infrequent exacerbations (IEs). FEs were defined as two or more flares occurring prior to a stroke, and IEs were defined as one or fewer incidents in the year prior to the stroke.
Overall, FEs did not differ from IEs in predicting the occurrence of a stroke in patients with COPD. Surprisingly, the risk of stroke decreased as exacerbations per year increased, a statistically significant effect. People with FE had a lower risk for stroke associated with hemorrhage than people with IE.
In their study report, the investigators concluded that there was “no evidence of a difference in the odds of stroke between IE and FE, suggesting that exacerbation frequency is unlikely to be the reason for increased stroke risk among COPD patients. Further research is needed to explore the association through investigation of stroke risk and the severity, duration, treatment of exacerbations, and concurrent treatment of cardiovascular risk factors.”
Exacerbations are unlikely, based on this study, to be a useful clinical predictor of a stroke in people with COPD. More research into risk factors for stroke in COPD patients is needed.