In-hospital cardiac arrest mortality rates are high. Among people who initially survive, only 12% to 25% live to leave the hospital. A retrospective cohort study was undertaken to identify prearrest, periarrest, and postarrest variables associated with in-hospital mortality among adults who had initially survived a cardiac arrest in the hospital.

Of the 925 patients who had an in-hospital cardiac arrest during a three-year period, 305 didn't initially survive and 349 died before hospital discharge, resulting in an overall survival rate of 29%. The final analyses included 620 patients who initially survived the arrest. In-hospital mortality was the primary outcome.

Recurrent cardiac arrest was the strongest predictor of in-hospital mortality, according to both a stepwise multivariable regression analysis that included the most complete data and a second regression model that included a subgroup of patients in whom data about serum lactate levels were available. Increasing age, increasing time to restoration of spontaneous circulation, higher serum creatinine levels, and a history of cancer were also predictors of in-hospital mortality. In the second model, increasing lactate levels were also found to be predictors of in-hospital mortality. Hypertension had a protective effect on survival.

Recurrent cardiac arrest was also the strongest predictor of the secondary outcome, an unfavorable discharge disposition, defined as death during hospitalization or discharge to a long-term acute care facility or hospice. Increasing age, increasing time to restoration of spontaneous circulation, higher serum creatinine levels, a history of cancer, and increasing lactate levels were also predictors of unfavorable outcomes, whereas hypertension was found to be protective.

The authors point out that the study had limitations inherent to a retrospective study, including the accuracy of electronic health records data.