Author response: Magnesium, hemostasis, and outcomes in patients with intracerebral hemorrhage

We appreciate the interest of Zheng et al. in our article on magnesium, hemostasis, and outcome in spontaneous intracerebral hemorrhage (SICH),¹ and their efforts investigating the topic. It is exciting that they observed an association between lower admission serum magnesium (ASM) and greater 30-day mortality, which is consistent with our findings and provides additional confirmatory evidence of a true ASM effect. While Zheng et al. did not demonstrate an association between ASM and 3-month mortality, there are potential reasons for this difference between our studies. We analyzed 3-month outcome using an ordinal rather than a binary mortality approach¹; it is possible the binary mortality approach missed a functional outcome effect. We also analyzed outcomes only in patients presenting within 6 hours of symptom onset and accounted for time from onset in our model. The morbid consequences of delayed medical attention in late-presenting patients may predispose them to future medical complications with an overwhelming effect on 3-month mortality. This would be consistent with our hypothesis of an acute hemostatic role of magnesium and literature, suggesting that neurologic deterioration occurs early (less than 12 hours)² and neurologic causes of death in SICH occur before 30 days while medical causes of death occur later.³