Out-of-hospital cardiac arrest in patients treated for ST-elevation acute myocardial infarction: Incidence, clinical features, and prognosis based on population-level data from Hungary

AIM: Out-of-hospital cardiac arrest (OHCA) is a severe complication of myocardial infarction. Literature data on the incidence of OHCA are inconsistent, and population-level data are incomplete. METHODS: Based on the Hungarian Myocardial Infarction Registry, the incidence of OHCA and its 30-day and 1-year mortality, as well as the significance of factors influencing the course of the disease in 28,083 ST-elevation myocardial infarction patients, were investigated using multivariable regression models. RESULTS: Of the 28,083 STEMI patients, 1535 (5.5%) had OHCA, which was more likely to occur in men. The long-term incidence of OHCA did not change significantly; no significant seasonality was found either. However, the daily distribution of cases showed that most OHCA patients were admitted to the hospital around 8 p.m. The occurrence of OHCA significantly worsened patients' prognoses; both 30-day and 1-year mortalities were considerably higher in the OHCA group than in the control group (46% vs 11.6%, 53.2% vs 18.7%, p < 0.001). This difference accumulated in the first few months; conditional survival after six months was no worse in those who had OHCA. Compared to those without OHCA, cardiogenic shock was more common at the time of hospitalisation (18.4% vs 2.2%) in the OHCA group. The highest risk of death was caused by the co-occurrence of OHCA and cardiogenic shock, which led to an eight times greater hazard of death (HR: 8.41, 95% CI: 7.37-9.60, p < 0.001). CONCLUSION: Multivariable analysis confirmed the independent prognostic significance of age, catheter intervention during the index hospitalisation, OHCA, and cardiogenic shock.