Emergency-transport N-terminal pro-B-type natriuretic peptide, renal function, and discharge outcome after acute stroke.

BACKGROUND: N-terminal pro-B-type natriuretic peptide (NT-proBNP) is often elevated in acute stroke, but reduced estimated glomerular filtration rate (eGFR) can complicate interpretation. We examined its association with poor discharge outcome after adjustment for registry variables. METHODS: We retrospectively studied 256 emergency-transported patients with ischemic stroke, intracerebral hemorrhage, or subarachnoid hemorrhage. The primary outcome was discharge modified Rankin Scale (mRS) 3-6. Logistic regression estimated odds ratios (ORs) per doubling of NT-proBNP, adjusted for age, sex, eGFR, and hemorrhagic stroke. Renal-function and subtype analyses were exploratory. RESULTS: The primary cohort included 212 patients; 137 (64.6%) had mRS 3-6. NT-proBNP, but not eGFR, was higher with poor outcome. The adjusted OR was 1.29 (95% confidence interval [CI] 1.12-1.50; P = 0.001). Renal-stratum ORs were 1.18 (95% CI 0.98-1.42) for eGFR ≥ 60 and 1.42 (95% CI 1.11-1.81) for eGFR < 60 mL/min/1.73 m2 (interaction P = 0.196). Exploratory subtype-specific ORs were 1.39 (95% CI 1.17-1.66) in ischemic stroke and 0.97 (95% CI 0.74-1.28) in intracerebral hemorrhage. The hemorrhagic-versus-ischemic interaction was not significant (P = 0.204). CONCLUSIONS: Early NT-proBNP was associated with poor discharge outcome after registry adjustment, without establishing independence from unmeasured confounding. Limited subgroup sizes prevented exclusion of effect modification. Predictive performance was not evaluated; the findings do not support routine clinical risk-stratification use.