Association Between Serum Ionized Calcium Levels and Neurological Outcomes in Patients with Out-of-Hospital Cardiac...

Area of Science:

• Critical Care Medicine
• Cardiovascular Research
• Neurocritical Care

Background:

• Out-of-hospital cardiac arrest (OHCA) remains a leading cause of death and disability.
• Post-cardiac arrest syndrome is characterized by calcium imbalance, but its prognostic significance is not well-defined.
• Targeted temperature management (TTM) is a standard therapy for OHCA survivors.

Purpose of the Study:

• To investigate the prognostic role of pH-adjusted ionized calcium levels in OHCA patients treated with TTM.
• To assess the association between baseline and longitudinal calcium levels and 30-day neurological outcomes and mortality.
• To evaluate the potential of serial ionized calcium measurements as a prognostic biomarker.

Main Methods:

• Retrospective analysis of 421 OHCA patients treated with TTM between 2011 and 2023.
• pH-adjusted ionized calcium levels measured serially (0, 12, 24, 48, 72 hours post-ROSC).
• Multivariable logistic regression used to assess associations with neurological outcomes and mortality.

Main Results:

• Higher baseline-adjusted ionized calcium levels were significantly associated with favorable neurological outcomes (CPC 1-2) and reduced 30-day mortality.
• Each 0.01-unit increase in calcium correlated with a 17% lower odds of unfavorable neurological outcome and a 10% lower mortality.
• Incorporating longitudinal calcium data improved the predictive accuracy for neurological outcomes (AUC increased from 0.843 to 0.919).

Conclusions:

• Early post-ROSC ionized calcium levels are independent predictors of neurological outcomes and mortality in TTM-treated OHCA patients.
• Serial ionized calcium monitoring shows promise as a prognostic marker in this population.
• Prospective studies are warranted to confirm these findings and explore therapeutic implications of calcium modulation.