Interplay between gender and pollution on the prognosis of resuscitated out-of-hospital cardiac arrest.

Background: Differences between men and women in prognosis after sudden pre-hospital out-of-hospital cardiac arrest (OHCA) have been described in many studies, but the interplay between gender and pollution have not been characterized in detail. We aimed at appraising the interplay between gender and pollution on the prognosis of OHCA.

Methods: Details on patients with OHCA in whom return of spontaneous circulation was obtained and transferred to a large teaching hospital were obtained from the medical charts of the ambulance service and the Polish National Health Fund. Matching pollutant concentrations (PM 2.5, PM10, As, Ni, Cd, Pb) were obtained from the Polish National Environmental Protection Inspectorate.

Results: Details on 948 resuscitated OHCA, 325 (34.3%) of them in women, and occurring between 2018 and 2021, were retrieved. Notably, OHCA in women was associated with significantly higher daily concentrations of PM10 (23.37 [17.09, 37.04] vs. 21.92 [16.32, 29.98] μg/m³, P=0.023) and PM2.5 (16.83 [11.87, 28.24] vs. 15.27 [11.64, 22.72] μg/m³, P=0.026), as well as heightened concentrations of Cd, daily (0.32 [0.19, 0.44] vs. 0.27 [0.17, 0.40] ng/m³, P=0.027) and over 30 days (0.34 [0.20, 0.44] vs. 0.29 [0.18, 0.43] ng/m³, P=0.027). Concurrently, OHCA in females was associated with lower daily temperatures on the day of the incident (8.40 [0.20, 15.40] vs. 9.90 [1.40, 15.90] °C, P=0.042). Despite these differences, survival at 30 days and 12 months was similar in women and men (both P>0.05).

Conclusions: OHCA events with successful resuscitation in women occurred in concomitance with higher daily contaminant levels, yet short-term and long-term prognosis was similar in men and women. The interplay between gender and air pollution on OHCA outcomes requires further population-based studies.