People with chronic obstructive pulmonary disease have an approximately 20% increased risk of stroke, and the risk is highest during the time after an acute exacerbation of COPD, data from a large epidemiologic study indicate.

The study also indicated that cigarette smoking was a strong risk factor for stroke and that hypertension management is important in COPD patients given the elevated risk for hemorrhagic strokes observed, according to Dr. Marileen L. P. Portegies of Erasmus MC University Medical Center, Rotterdam, the Netherlands, and her colleagues.

In 13,115 participants from the Rotterdam study, people with COPD had a 6.7-fold increase in the risk of stroke within the first 7 weeks of a severe exacerbation (hazard ratio, 6.66; 95% confidence interval, 2.42-18.20).

The study ( Am J Respir Crit Care Med. 2016; 193:251-8 ) found that 1,250 of the participants had a stroke (701 were ischemic and 107 hemorrhagic) over 126,347 person-years of follow-up.

After researchers adjusted for age and sex, COPD was significantly associated with all stroke (HR, 1.20; 95% CI, 1.00-1.43), ischemic stroke (HR, 1.27; 95% CI, 1.02-1.59), and hemorrhagic stroke (HR, 1.70; 95% CI, 1.01-2.84).

Smoking was the strongest explanatory factor for the association between COPD and stroke, the researchers said. Adjustments for cardiovascular risk factors gave similar effect sizes, whereas adjustments for smoking attenuated the effect sizes: for all stroke, (HR, 1.09; 95% CI, 0.91-1.31); for ischemic stroke, (HR, 1.13; 95% CI, 0.91-1.42) ; and for hemorrhagic stroke, (HR 1.53; 95% CI, 0.91-2.59) .

“Our study reveals the importance of smoking as a shared risk factor and implicates that clinicians should be aware of the higher risk of both stroke subtypes in subjects with COPD, especially after severe exacerbations,” they concluded.

Writing in an accompanying editorial Dr. Janice M. Leung and Dr. Don D. Sin from St. Paul’s Hospital University of British Columbia, Vancouver, said there was no doubt that cardiovascular disease, stroke, and COPD all shared smoking as a common risk factor.

But smoking alone failed to account for the particularly critical period of a COPD exacerbation during which the risk for strokes and myocardial infarctions exponentially increase.

“Surely, this acute period must offer clues as to why such a strong link exists among the lung, heart, and brain in COPD,” the researchers wrote.

COPD exacerbations may represent a time of intense oxidative stress and systemic inflammation that drive endothelial dysfunction, vascular reactivity, and even atherosclerotic plaque rupture.

“Pulmonologists must work closer with cardiologists and neurologists to enable optimal vascular care for patients with COPD, because it is clear that the lungs do not stand alone and that COPD, although a lung disease, is a major risk factor for stroke, especially during exacerbations,” they concluded.