Predictors and rate of survival after Out-of-Hospital Cardiac Arrest

Abstract

Background: Out-of-hospital cardiac arrest (OHCA) is a major public health concern and encloses a wide spectrum of causes. The purpose of this study is to assess predictors and rate of survival at hospital discharge and long-term in the setting of OHCA. The secondary endpoint is to compare OHCA-survival outcomes of presumed ischemic versus non ischemic cause.

Methods: A retrospective cohort was conducted on 318 consecutive patients admitted for OHCA at Civilian Hospitals of Colmar between 2010 and 2019. Data concerning baseline characteristics, EKG, biological parameters, and coronary angiograms were collected. We observed the living status (alive or dead) of each of study's participants by March 2023.

Results: The observed survival rate was 34.3 % at hospital discharge and 26.7 % at 7.1-year follow up. The mean age of study population was 63 ± 16 years and 32.7 % were women. 65.7 % of OHCA-patients underwent coronary angiography that revealed a significant coronary artery disease (CAD) in half of study participants. Primary angioplasty was performed in 43.4 % of study population. The in-hospital mortality rate was significantly higher in those with RBBB (83.7 % vs. 62.5 %, p = 0.004), diabetes mellitus (84.2 % vs. 59.9 %, p < 0.001), arterial hypertension (72.2 % vs. 57.7 %, p = 0.007), peripheral arterial disease (79.2 % vs. 52.2 %, p = 0.031) whereas it was lower in case of anterior STEMI (43.9 % vs 71.4 %, p < 0.001), presence of obstructive CAD (52.2 % vs. 79.2 %, p < 0.001), primary angioplasty performance (48.6 % vs. 78.9 %, p < 0.001), initial shockable rhythm (43.8 % vs. 88.6 %, p < 0.001), initial chest pain (49.4 % vs. 71.5 %, p < 0.001). After adjusting on covariates, the Cox model only identified an initial shockable rhythm as independent predictor of survival at hospital discharge [HR = 0.185, 95 %CI (0.085-0.404), p < 0.001] and 7-year follow up [HR = 0.201, 95 %CI (0.082-0.492), p < 0.001]. The Kaplan-Meier and log Rank test showed a difference in survival outcomes between OHCA with versus without CAD (p < 0.001).

Conclusion: The proportion of OHCA-survivors is small despite the development of emergency health care system. Initial shockable rhythm is the strong predictor of survival. OHCA of presumed coronary cause is associated with a better long-term survival outcome.

Keywords: Cardiac cause; OHCA; Shockable rhythm; Survival.