Gender-specific differences in return-to-spontaneous circulation and outcome after out-of-hospital cardiac arrest: Results of sixteen-year-state-wide initiatives

AIM: Several studies reported a lower proportion of laypeople cardio-pulmonary resuscitation (CPR) in female victims of out-of-hospital cardiac arrest (OHCA). We aimed to verify how sixteen-years of state-wide initiatives impacted on gender-differences in OHCA treatment and survival. METHODS: All the 2481 consecutive OHCAs of presumed cardiac origin occurred between 2002 and 2018 in the Swiss Ticino Canton and in which a resuscitation was attempted, were included. Emergency medical system (EMS)-witnessed OHCAs were excluded. RESULTS: Time from call to CPR decreased from 9-min in 2002–2006 to 5-min in 2015–2018 (p < 0.01) and until 2014, it was longer in women. Survival to discharge increased overall from 11% in 2002–2006 to 23% in 2015–2018 (p < 0.001) related to telephone-assisted CPR development (period 2011–2014) and first responder and layperson recruitment via a mobile application (period 2015–2018). In males, survival increased from 12% to 25% (p = 0.001) with a statistically significant increase in odds of survival in 2007–2010 (OR 1.6 95%CI 1.1–2.3; p = 0.001), in 2011–2014 (OR 2 95%CI 1.4–2.8; p = 0.001), and in 2015–2018 (2.4 95%CI 1.7–3.3; p = 0.001) compared to 2002–2006. On the other hand, in females, survival increased from 7% to 18% (p < 0.001), with a corresponding increase in the odds of survival of almost 3 times from 2002–2006 to 2015–2018 time period (OR 2.9 95%CI 1.5–5.8, p = 0.001). No difference in survival probability was observed according to gender when adjusted for age, presenting rhythm, year-groups, OHCA location, EMS arrival time, witnessed status and laypeople-CPR. CONCLUSIONS: State-wide initiatives can significantly increase the chances of survival in both male and female victims of OHCAs, by increasing the probability to receive CPR in a shorter time span.