Predicting Cardioembolic Stroke with the B-Type Natriuretic Peptide Test: A Systematic Review and Meta-analysis

Background: We performed a systematic review and meta-analysis to evaluate the value of B-type natriuretic peptide (BNP) in differentiating cardioembolic (CE) stroke from other subtypes of ischemic stroke. Methods: We searched the EMBASE, MEDLINE, and Cochrane databases and reference lists of relevant articles published in April 2013. We selected original studies reporting the performance of BNP or N-terminal probrain natriuretic peptide (NT-proBNP) in diagnosing CE stroke and summarized test performance characteristics using forest plots, hierarchical summary receiver operating characteristic curves, and bivariate random-effect models. Results: Data from 2958 patients with ischemic stroke were retrieved from 16 studies. Of these, 1024 (34.6%) patients had a final diagnosis of CE stroke. Overall, the mean diagnostic odds ratio (DOR) of BNP for CE stroke was 15.8 (95% confidence interval [CI]: 9.92-25.20). Even after adjustment for multiple clinical predictors, serum natriuretic peptide levels showed a strong association with CE stroke (pooled adjusted DOR, 12.7; 95% CI: 7.32-22.0). The sensitivity and specificity of BNP for CE stroke were .78 (95% CI:.71-.87) and .83 (95% CI:.77-.87), respectively. A single BNP-negative result may be sufficient to exclude a diagnosis of CE stroke in low-prevalence (<20%) settings. Subgroup analysis showed that NT-proBNP had a slightly higher specificity (.87; 95% CI:.77-.93) and better capability for exclusion diagnosis. There was a lack of homogeneity in the timing of measurement and BNP assay method. Conclusions: BNP has reasonable accuracy in the diagnosis of CE stroke and may be a useful marker for the early detection in patients who may benefit from preventive anticoagulation therapy.