Background and Aim: There is little evidence on the prognostic significance of hyponatremia in patients with intracerebral hemorrhage (ICH). The aim of this study was to clarify the association of hyponatremia with clinical outcomes and to determine the relationship between hyponatremia and hematoma and perihematomal edema growth.
Methods: This study was a subsidiary, post-hoc analysis of INTERACT 1 and 2; which were randomised controlled trials of patients with acute spontaneous ICH with elevated systolic blood pressure (BP), randomly assigned to intensive (target systolic BP < 140 mmHg) or guideline-based (< 180 mmHg) BP management. Hyponatremia was defined as serum sodium < 135 mEq/L. The primary clinical outcome was death at 90 days. The outcomes of the CT substudies were absolute growth of hematoma and perihematomal edema volume in 24 hours.
Results: Among 3002 patients with information on sodium and clinical outcomes, 349 (12%) had hyponatremia, which was associated with death at 90 days (multivariable-adjusted OR, 2.03; 95% CI, 1.41-2.91; p=0.0001). In the hematoma growth and perihematomal edema growth analyses, there were 1241 and 790 patients included, respectively. No associations were observed for hematoma growth or perihematomal edema growth during the first 24 hours.
Conclusions: Hyponatremia is associated with higher mortality at 90 days in patients with spontaneous ICH. Hyponatremia does not appear to affect perihematomal edema growth or hematoma volume growth.