Trends in survival after cardiac arrest: a Swedish nationwide study over 30 years

Abstract

Aims: Trends in characteristics, management, and survival in out-of-hospital cardiac arrest (OHCA) and in-hospital cardiac arrest (IHCA) were studied in the Swedish Cardiopulmonary Resuscitation Registry (SCRR).

Methods and results: The SCRR was used to study 106 296 cases of OHCA (1990-2020) and 30 032 cases of IHCA (2004-20) in whom resuscitation was attempted. In OHCA, survival increased from 5.7% in 1990 to 10.1% in 2011 and remained unchanged thereafter. Odds ratios [ORs, 95% confidence interval (CI)] for survival in 2017-20 vs. 1990-93 were 2.17 (1.93-2.43) overall, 2.36 (2.07-2.71) for men, and 1.67 (1.34-2.10) for women. Survival increased for all aetiologies, except trauma, suffocation, and drowning. OR for cardiac aetiology in 2017-20 vs. 1990-93 was 0.45 (0.42-0.48). Bystander cardiopulmonary resuscitation increased from 30.9% to 82.2%. Shockable rhythm decreased from 39.5% in 1990 to 17.4% in 2020. Use of targeted temperature management decreased from 42.1% (2010) to 18.2% (2020). In IHCA, OR for survival in 2017-20 vs. 2004-07 was 1.18 (1.06-1.31), showing a non-linear trend with probability of survival increasing by 46.6% during 2011-20. Myocardial ischaemia or infarction as aetiology decreased during 2004-20 from 67.4% to 28.3% [OR 0.30 (0.27-0.34)]. Shockable rhythm decreased from 37.4% to 23.0% [OR 0.57 (0.51-0.64)]. Approximately 90% of survivors (IHCA and OHCA) had no or mild neurological sequelae.

Conclusion: Survival increased 2.2-fold in OHCA during 1990-2020 but without any improvement in the final decade, and 1.2-fold in IHCA during 2004-20, with rapid improvement the last decade. Cardiac aetiology and shockable rhythms were halved. Neurological outcome has not improved.

Keywords: Cardiac arrest; Cardiovascular disease; Heart disease; Resuscitation.

Structured Graphical Abstract

The Swedish Cardiopulmonary Resuscitation Registry was used to study 30-year trends in out-of-hospital cardiac arrest (OHCA) and 17-year trends in in-hospital cardiac arrest (IHCA). A total of 106 296 cases of OHCA (1990–2020) and 30 032 cases of IHCA (2004–20), in whom resuscitation was attempted, were studied. Trends in 30-day survival, cerebral performance category among survivors, causes of cardiac arrest, initial rhythm, critical time intervals, and bystander cardiopulmonary resuscitation (CPR) were studied.

Figure 1

Survival and characteristics in out-of-hospital cardiac arrest during 1990–2020. (A–H) Shows trends in characteristics, management and survival in out-of-hospital cardiac arrest in Sweden during 1990–2020. All results are adjusted, using logistic regression, for age and sex, except from critical time intervals and rates of bystander cardiopulmonary resuscitation (provided as crude numbers). Smooth lines depict a polynomial regression line to visualize the trend. Note some y axes in some panels are truncated. Odds ratios and P-values for calendar year modelled as a linear predictor are provided in Supplementary material online, Table S3. OR = odds ratio.

Figure 2

Survival and characteristics in in-of-hospital cardiac arrest during 2004–20. (A–H) shows trends in characteristics, management and survival in in-hospital cardiac arrest in Sweden during 2004–20. All results are adjusted, using logistic regression, for age and sex, except from critical time intervals (provided as crude numbers). Smooth lines depict a polynomial regression line to visualize the trend. Note some y axes in some panels are truncated. Odds ratios and P-values for calendar year modelled as a linear predictor are provided in Supplementary material online, Table S3. OR = odds ratio.