Association of higher serum calcium levels with smaller infarct volumes in acute ischemic stroke.

BACKGROUND

Elevated serum calcium levels at admission in patients with stroke have been associated with less severe clinical deficits and with better outcomes; however, the relationship between serum calcium levels and volumetric measurement of cerebral infarct size on neuroimaging has not been studied, to our knowledge.

OBJECTIVE

To assess the relationship between serum calcium levels at admission and initial diffusion-weighted magnetic resonance imaging (DWI) infarct volumes among patients with acute ischemic stroke.

DESIGN

Secondary analysis of prospectively collected hospital quality improvement data.

SETTING

Tertiary university hospital.

PATIENTS

One hundred seventy-three consecutive patients with acute ischemic stroke initially seen within 24 hours of the last known well time.

MAIN OUTCOME MEASURES

Total serum calcium levels were measured on admission and were collapsed into quartiles. The DWI lesions were outlined using a semiautomated threshold technique. The relationship between serum calcium level quartiles and DWI infarct volumes was examined using multivariate quartile regression analysis.

RESULTS

One hundred seventy-three patients (mean age, 70.3 years [age range, 24-100 years]; median National Institutes of Health Stroke Scale score, 4 [range, 0-38]) met the study criteria. The median DWI infarct volumes for the serum calcium level quartiles (lowest to highest quartile) were 9.42, 2.11, 1.03, and 3.68 mL. The median DWI infarct volume in the lowest serum calcium level quartile was larger than that in the other 3 quartiles (P < .005). After multivariate analysis, the median adjusted DWI infarct volumes for the serum calcium level quartiles (lowest to highest) were 8.9, 5.8, 4.5, and 3.8 mL. The median adjusted DWI infarct volume in the lowest serum calcium level quartile was statistically significantly larger than that in the other 3 quartiles (P < .05).

CONCLUSIONS

Higher serum calcium levels at admission are associated with smaller cerebral infarct volumes among patients with acute ischemic stroke. These results suggest that serum calcium level may serve as a clinical prognosticator following stroke and may be a potential therapeutic target for improving stroke outcome.