The association of admission ionized calcium with outcomes of thrombolysed patients with anterior circulation ischemic stroke

BACKGROUND AND PURPOSE: The relationship between ionized calcium and prognosis of ischemic stroke is controversial. We aim to determine the relationship of admission ionized calcium levels with acute ischemic stroke (AIS) after intravenous thrombolysis (IVT). METHODS: Consecutive anterior circulation AIS patients treated with recombinant tissue plasminogen activator (rt‐PA) were retrospectively enrolled. According to ionized calcium quartiles, the patients were divided into four groups and clinical data were analyzed between groups. Ionized calcium was entered into logistic regression analysis in two models, separately: model 1, calcium as a continuous variable (per 1‐mmol/L increase), and model 2, calcium as the four‐categorized variable (being collapsed into quartiles: Q1–Q4). Early neurologic improvement (ENI) was defined as improvement of four or more points at 24 h after intravenous rt‐PA, while long‐term good outcome as the modified Rankin Scale (mRS) 0–1 at 90 days. RESULTS: A total of 546 patients met the study criteria (mean age was 63.51 ± 11.26 years and 365 [66.8%] were men). The median admission National Institute of Health Stroke Scale was 9 (range 4 to 15). When not adjusted, in model 1: ionized calcium was related to good outcome (odds ratio [OR] 69.061, 95%CI: 1.638–2911.111, p=0.027), but not ENI (OR 14.097, 95%CI: 0.133–1492.596, p=0.266); in model 2: compared with Q4, while good outcome was less common in Q1 (OR 0.623, 95%CI: 0.388–0.999, p=0.049). After adjusting for confounding factors, calcium in Q2 (OR 0.502, 95%CI: 0.253–0.997, p=0.049) was independently associated with ENI, but no matter as a continuous variable or categorized variable, ionized calcium displayed no association with a good outcome. CONCLUSION: The current results found that ionized calcium might be associated with early neurological improvement, but had no association with 3 months' outcome in anterior circulation AIS patients after IVT.