Predictors of recurrent stroke in Chinese population identified
Chinese patients with ischaemic stroke involving posterior circulation should be more carefully monitored for recurrence if they have dysphagia at admission, repeated transient ischemic attack (TIA) before the stroke, ≥70 percent stenosis of the responsible artery, multisector infarcts, and no antithrombotic treatment at discharge.
This recommendation is based on a recent prospective study conducted by researchers from Beijing and Hong Kong to identify clinical and radiological parameters that can assist in predicting ischaemic stroke recurrence. Data of 723 Chinese patients with noncardiogenic ischaemic stroke involving posterior circulation were retrieved for analysis. [Stroke 2017;48:1835-1841]
Among these patients, 5.5 percent (n=40) had recurrent ischaemic stroke or TIA at 1 year.
Dysphagia at admission (hazard ratio [HR], 4.16; p=0.002), repeated TIAs within 3 months before the stroke (HR, 15.4; p<0.0001), ≥70 percent stenosis of the responsible artery (HR, 7.91; p=0.05) and multisector infarcts (HR, 5.38; p=0.02) were found to correlate with recurrent ischaemic stroke or TIA within 1 year after adjusting for age, sex and vascular risk factors.
In addition, patients who were not on antithrombotic treatment at discharge had a higher risk of recurrence (HR, 3.06; p=0.03), reflecting the importance of effective secondary prevention following ischaemic stroke involving posterior circulation.
“Preventive treatment should be offered to patients with these high-risk features as soon as possible,” the study authors suggested.
“Ischaemic stroke involving posterior circulation is associated with poor prognosis due to its high rates of recurrence, mortality and severe disability,” they noted. “Several predictive scores have been developed to identify patients at high risk of recurrent ischaemic stroke. However, most of the scores do not include stenosis of the responsible artery and imaging features of acute infarcts as predictive factors of ischaemic stroke.”
“Severe stenosis of the artery responsible for the ischaemic stroke may cause hypoperfusion and embolism of the distal artery as well as occlusion of small penetrating artery, which in turn increases the risk of recurrent stroke or TIA as demonstrated in our study,” the authors wrote.
“Multiple acute infarcts are often caused by small emboli from an unstable source, such as rupture of plaque in a large artery with atherosclerosis. Therefore, thromboembolism may be the predominant cause of ischaemic stroke in patients with multisector infarcts,” they explained. “These patients were found to have a higher risk of recurrence because they may have a higher chance of second rupture of unstable atherosclerotic plaque or acute occlusion of the responsible artery.”
In the study, patients with dysphagia at admission more often had multisector and multilevel infarcts, which might explain the higher risk of recurrent ischaemic stroke or TIA in this subgroup.
“In contrast, facial palsy was associated with a lower risk of ischaemic stroke or TIA recurrence [HR, 0.41; p=0.04],” the authors noted. “This is perhaps because the majority of patients with facial palsy at admission had single infarct rather than multisector infarct [78.1 vs 8.5 percent].”