Does CHA2DS2-VASc score predict ischaemic stroke in chronic obstructive pulmonary disease?

Chronic obstructive pulmonary disease (COPD) is associated with a high risk of ischaemic stroke.1 CHA2DS2-VASc score is recommended and is widely used for stroke risk stratification in atrial fibrillation (AF) patients,2 but it has been shown to be an independent predictor of thrombo-embolic events in patients without AF, as well.3 In this issue of Europace, Hu et al. performed a retrospective cohort study in a very big case sample (1492 COPD patients with AF and 50 343 COPD patients without AF), and reported that COPD patients with a higher CHA2DS2-VASc score were more likely to develop ischaemic stroke whether or not AF was present.4 The corresponding adjusted hazard ratio (HR) of ischaemic stroke was 7.57 (95% CI = 6.15–9.32) for COPD patients without AF with a CHA2DS2-VASc score of ≥6 compared with those with a CHA2DS2-VASc score of 0, after adjusting for hyperlipidaemia and chronic kidney disease. The C-statistics of CHA2DS2-VASc score in predicting ischemic stroke in COPD patients with and without AF were 0.58 (95% CI = 0.55–0.62) and 0.71 (95% CI = 0.70–0.72), respectively.4 This is a very interesting finding, as it shows that COPD patients without AF are prone to develop stroke at a lower CHA2DS2-VASc score threshold than those with AF.4 Possible explanation for this phenomenon is that the components of CHA2DS2-VASc score, including hypertension, diabetes mellitus, heart failure, advanced age, previous history of thrombo-embolic event, and peripheral artery disease, are well-established risk factors for stroke development.4 In another recent retrospective cohort study, Ooi et al.5 also reported that COPD patients have an increased risk of ischaemic stroke. Notably, the C-statistics of CHA2DS2-VASc score in predicting ischaemic stroke in COPD patients was similar (AUC = 0.739) with the results of Hu et al.5 The researchers also reported an adjusted HR of ischaemic stroke 2.14 for COPD patients with CHA2DS2-VASc score ≥6.5 These results are of outmost importance as they highlight that CHA2DS2-VASc score may predict ischaemic stroke better for COPD patients without AF than for COPD patients with AF. Early lifestyle modifications and better management of risk factors included in the CHA2DS2-VASc score seem to be crucial for ischaemic stroke prevention in COPD. Furthermore, antithrombotic therapy may be essential for COPD patients with a high CHA2DS2-VASc score (i.e. ≥6). More studies are needed to confirm these observations and to provide evidence that antithrombotic therapy is necessary for COPD patients with high CHA2DS2-VASc score. Conflict of interest: none declared.