Time course of NT-proBNP levels after acute ischemic stroke.

Background: Studies suggest that N-terminal-pro-brain natriuretic peptide (NT-proBNP) can be a biomarker of cardioembolic stroke. However, the best time to measure it after stroke is unknown. We studied the time course of NT-proBNP in patients with ischemic stroke.

Methods: Consecutive acute ischemic stroke patients were admitted over 10 months to a Stroke Unit. Stroke type was classified according to TOAST. Blood samples were drawn within 24, 48, and 72 hours after stroke. Friedman test was used to compare NT-proBNP values across the 3 times in all, cardioembolic and non-cardioembolic stroke patients. Post hoc analysis with Wilcoxon signed-rank tests was conducted with a Bonferroni correction. Mann-Whitney test was used to compare median values of NT-proBNP between cardioembolic and non-cardioembolic stroke patients. ROC curves were drawn to determine NT-proBNP accuracy to diagnose cardioembolic stroke at 24, 48, and 72 hours after stroke onset.

Results: One hundred and one patients were included (29 cardioembolic) with a mean age of 64.5±12.3 years. NT-proBNP values for cardioembolic stroke were significantly higher (P < 0.001) than for non-cardioembolic stroke in the 3 time points. NT-proBNP was highest in the first 24-48 h after ischemic stroke and decreased significantly 72 h after stroke onset. The area under the curve for the three time points was similar.

Conclusion: NT-proBNP levels were highest in the first 2 days after ischemic stroke and declined significantly thereafter. However, the area under the curve for the three time points was similar. The first 72 hours after ischemic stroke have a similar diagnostic accuracy to diagnose cardioembolic stroke.