Both CPR rates and survival rates increased after chest compression–only CPR was introduced as an alternative for bystanders witnessing a cardiac arrest, according to a Swedish study of out-of-hospital cardiac arrests and subsequent CPR.

A man practices chest-compression CPR © American Heart Association, Inc.

“These findings support continuous endorsement of chest compression–only CPR as an option in future CPR guidelines because it is associated with higher CPR rates and survival in out-of-hospital cardiac arrests,” wrote Gabriel Riva, MD, of the Karolinska Institutet, Stockholm, and his coauthors. The study was published in Circulation.

To determine changes in the rate and type of CPR performed before emergency medical services (EMS) arrival, the researchers compared all bystander-witnessed out-of-hospital cardiac arrests (OHCAs) reported in Sweden between 2000 and 2017. In all, 30,445 patients were included; the time periods compared were 2000-2005, 2006-2010, and 2011-2017. Patients were categorized as receiving either no CPR (NO-CPR), standard CPR (S-CPR), or chest compression–only CPR (CO-CPR). In 2005, CO-CPR was introduced in national CPR guidelines as an option for bystanders; in 2010, it was recommended for anyone untrained in CPR.

The proportion of patients who received CPR in general increased from 41% in 2000-2005 to 59% in 2006-2010 to 68% in 2011-2017. S-CPR changed from 35% to 45% to 38% over the three periods, while CO-CPR increased from 5% to 14% to 30%. In regard to 30-day survival rates, the S-CPR group saw an increase from 9% to 13% to 16% and the CO-CPR group increased from 8% to 12% to 14%, compared with 4% to 6% to 7% for the NO-CPR group.

The authors noted the limitations of their study, including the results being based on register data and therefore subject to misclassification and missing data. In addition, missing data negated any reporting on the neurological function of survivors; analyzing witnessed OHCAs only also meant the findings could not be validated for nonwitnessed OHCA.

The Swedish Heart and Lung Foundation funded the study. The authors made no disclosures.

SOURCE: Riva G et al. Circulation. 2019 Apr 1. doi: 10.1161/CIRCULATIONAHA.118.038179.