Prehospital cardiac arrest and the adverse effect of male gender, but not age, on outcome

Abstract

Objective: To analyze the incidence and outcome of prehospital cardiac arrest as it correlated to gender and age as a secondary end point in an interventional clinical trial.

Methods: This prospective, randomized, double-blinded clinical intervention trial enrolled 874 prehospital cardiopulmonary arrest patients encountered by prehospital urban, suburban, and rural regional emergency medical service (EMS) areas. This trial evaluated outcome and profiled demographic predictors of cardiac arrest patients refractory to defibrillation with intravenous access who underwent standard advanced cardiac life support (ACLS) intervention and empiric early administration of bicarbonate. Survival was measured to the emergency department (ED), and data analysis used chi-square with Pearson correlation.

Results: The overall survival rate was 14.2%. There was no age correlate to survival, with an average age of 67.4 for both groups. Male patients had a 2.4-fold increased incidence (70.7 vs. 29.3%, p = 0.001) of arrest, which was associated with a 60% increase in mortality (19.6% vs. 11.8, p = 0.004) compared with women. The risk of unfavorable outcome was increased for men (OR 1.826, 95% CI 1.182-2.821; RR 1.097, 95% CI 1.025-1.180) on univariate analysis. There appeared to be no intergroup differences found with other historical variables, such as the presence of myocardial infarction (MI), hypertension (HTN), diabetes mellitus (DM), congestive heart failure (CHF), and chronic obstructive pulmonary disease (COPD), which were analyzed. However, HTN was found more commonly (2.2 times) in men (69.1 vs. 30.9%) than in women but did not correlate with survival.

Conclusions: Male gender, but not age, is associated with both an increased incidence and a worsened outcome in prehospital cardiac arrest.