D2.122 - Impact of Asthma on Outcomes after out-of-hospital cardiac arrest: A nationwide pathway-based analysis, 2013-2023

Asthma is a chronic inflammatory airway disease associated with acute respiratory compromise, yet its prognostic impact on out-of-hospital cardiac arrest (OHCA) outcomes remains poorly defined. We evaluated the nationwide OHCA registry of South Korea to investigate the neurological and survival outcomes of asthma-related OHCA in a population-based setting.

Using a nationwide OHCA registry from 2013 to 2023, we examined the association between a history of asthma and clinical outcomes among adult patients with OHCA (n=331,152). Patients were categorized according to post–emergency department (ER) care pathways (ER-level outcome vs post-ER admission). Multivariable logistic regression models adjusted for age, sex, insurance type, OHCA etiology, and care pathway were used to evaluate overall mortality. Additional analyses assessed initial shockable rhythm at ER arrival and neurological outcomes among survivors.

Patients with asthma were older, more often female, and less likely to present with a shockable rhythm. Despite higher survival at emergency department, they showed poorer neurological outcomes at discharge, with no significant difference in overall mortality (Table 1). Among the study population, a history of asthma was independently associated with increased mortality (adjusted odds ratio [OR] 1.33, 95% confidence interval [CI] 1.10–1.63, P = 0.005) (Figure 1). This association was consistent across patients with ER-level outcomes (OR 1.27, 95% CI 1.05–1.56, P = 0.019) and those admitted after ER care (OR 1.25, 95% CI 1.12–1.39, P < 0.001). Patients with asthma were significantly less likely to present with a shockable rhythm at ER arrival (OR 0.53, 95% CI 0.41–0.66, P < 0.001). Among survivors, asthma was associated with poorer neurological outcomes, with a reduced likelihood of favorable cerebral performance category scores (OR 0.71, 95% CI 0.59–0.85, P < 0.001).

A history of asthma is associated with worse outcomes after OHCA, including higher mortality, unfavorable initial cardiac rhythm, and poorer neurological recovery among survivors. These findings suggest that asthma confers intrinsic vulnerability across multiple stages of OHCA care, beyond differences in post-resuscitation treatment pathways.