Magnesium Sulfate in Cardiogenic Shock Patients: A Retrospective Propensity Score-Matched Cohort Study

Magnesium ions are essential inorganic ions in the body, playing a crucial role in normal physiological functions. Previous studies have shown that supplementing magnesium sulfate can provide survival advantages for critically ill patients. Our study aimed to explore whether intravenous magnesium sulfate could provide a survival advantage in patients with cardiogenic shock (CS).

This is a retrospective cohort study based on the Medical Information Mart in Intensive Care (MIMIC) IV database. The study participants were CS patients. The study endpoints were 30-day, 90-day, and 360-day all-cause mortality. The external validation was performed in the eICU 2.0 database.

The pre-matched and propensity score-matched (PSM) cohorts included 2547 and 830 patients, respectively. In the overall patient cohort, multivariable Cox regression showed that magnesium supplementation was associated with a reduced risk of 30-day (HR 0.635; 95% CI 0.539, 0.749; p < 0.001), 90-day (HR 0.687; 95% CI 0.591, 0.749; p < 0.001), and 360-day all-cause mortality (HR 0.681; 95% CI 0.593, 0.782; p < 0.001). This association remained consistent after PSM in 30-day (HR 0.624; 95% CI 0.506, 0.768; p < 0.001), 90-day (HR 0.640; 95% CI 0.530, 0.774; p < 0.001), and 360-day all-cause mortality (HR 0.629; 95% CI 0.529, 0.749; p < 0.001). Subgroup analysis found that the effect of the magnesium supplement was consistent in different subgroup patients, including in patients with hypomagnesemia versus non-hypomagnesemia (all p-interaction > 0.05). In 1867 CS patients from eICU 2.0 for external validation, after PSM, intravenous magnesium sulfate use was associated with lower in-hospital (HR 0.742; 95% CI 0.578, 0.952; p = 0.019) and in-ICU all-cause mortality (HR 0.729; 95% CI 0.555, 0.958; p = 0.023).

Intravenous magnesium sulfate use was associated with reduced risk of all-cause mortality in patients with CS, and this benefit was not affected by patients' serum magnesium levels. Prospective studies are warranted to verify this finding.