Objective To investigate the clinical value of plasma brain natriuretic peptide(BNP) levels and serum troponin I(cTnI) as biomarkers for the diagnosis of cardiogenic stroke.

Methods The clinical data of 235 patients with acute ischemic stroke(including 66 cases of cardiac stroke and 169 cases of non-cardiogenic stroke).By comparing the plasma BNP and cTnI levels between two groups, the optimal cut-off values of BNP and cTnI levels in the diagnosis of cardiogenic stroke were determined, and the diagnostic value of the two was compared.

Results Compared with the non-cardiogenic stroke group, the older age(P < 0.01), larger left atrial diameter(P < 0.01), higher incidence of atrial fibrillation and mitral regurgitation(P < 0.01), lower incidence of diabetes(P < 0.05) and smaller albumin in the cardiogenic stroke group were found(P < 0.01).The plasma BNP level and cTnI value in patients with cardiogenic stroke were significantly higher than those in patients without cardiogenic stroke(P < 0.01).The area under the ROC curve of plasma BNP level was 0.986, and the 95% confidence interval was 0.972-0.999.The area under the ROC curve of cTnI value was 0.941, and its 95% confidence interval was 0.896-0.987.The optimal cut-off point of plasma BNP level for the diagnosis of cardiogenic stroke was 89.31 pg/mL(sensitivity for 92.4% and specificity for 98.8%), and the optimal cut-off point of cTnI for distinguishing cardiogenic stroke from non-cardiogenic stroke was 0.019 5 ng/mL(sensitivity for 87.9%, specificity for 95.9%).

Conclusions When the plasma BNP level and cTnI value of ischemic stroke patients exceed 89.31 pg/mL and 0.019 5 ng/mL, respectively, it has important clinical significance for the differential diagnosis of cardiogenic stroke and non-cardiogenic stroke, and the clinical value of plasma BNP level in the diagnosis of cardiogenic stroke is higher than that of cTnI.