Interarm blood pressure difference is associated with early neurological deterioration, poor short-term functional outcome, and mortality in noncardioembolic stroke patients

Background and Purpose Interarm differences in the systolic and diastolic blood pressures (IASBD and IADBD, respectively) are found in various populations, including stroke patients, but their significance for stroke outcomes has rarely been reported. We aimed to determine the associations of IASBD and IADBD with early neurological deterioration (END), functional outcome, and mortality.Methods This study included 1,008 consecutive noncardioembolic cerebral infarction patients who were admitted within 24 hours of onset and had automatic measurements of blood pressures in the bilateral arms. END was assessed within 72 hours of stroke onset according to predefined criteria. A poor functional outcome was defined as a score on the modified Rankin Scale ≥3 at 3 months after the index stroke. All-cause mortality was also investigated during a median follow-up of 24 months. The absolute difference of blood pressure measurements in both arms were used to define IASBD and IADBD.Results END occurred in 15.3% (155/1,008) of the patients. A multivariate analysis including sex, age, and variables for which the p value was <0.1 in a univariate analysis revealed that IASBD ≥10 mm Hg was significantly associated with END [odds ratio (OR)=1.75, 95% CI=1.02– 3.01]. IADBD ≥10 mm Hg was also related to END (OR=3.11, 95% CI=1.61–5.99). Moreover, having both IASBD ≥10 mm Hg and IADBD ≥10 mm Hg was related to a poor functional outcome (OR=2.67, 95% CI=1.36–5.35) and mortality (hazard ratio=7.67, 95% CI=3.76–12.83) even after adjusting for END. Conclusions This study suggests that an interarm blood pressure difference of ≥10 mm Hg could be a useful indicator for the risks of END, poor functional outcome, and mortality.