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Compression Only CPR Versus Standard CPR in Out-Of-Hospital Cardiac Arrest - A Randomized Survival Study

A Randomized Trial Comparing Survival After of a Simplified Form of Cardiopulmonary Resuscitation (CPR) Consisting of Compressions Only Compared to CPR With Compressions and Rescue Breaths

Status
Recruiting
Phases
Unknown
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT03981107
Acronym
TANGO2
Enrollment
3260
Registered
2019-06-10
Start date
2017-01-01
Completion date
2028-12-31
Last updated
2026-05-08

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Cardiac Arrest, Cardiopulmonary Resuscitation, Out-Of-Hospital Cardiac Arrest

Keywords

Cardiopulmonary Resuscitation, Chest compressions only CPR, Dispatcher assisted CPR, Cardiac Arrest

Brief summary

Out-of-hospital cardiac arrest (OHCA) is one of the leading causes of mortality in the industrialized world. Bystander CPR before arrival of the Emergency Medical Service (EMS) is associated with an increased chance of survival. During the last decade, the best form of bystander CPR has been debated. Chest Compression Only CPR (CO-CPR) has been advocated as a preferable method in situations where the bystander has no previous knowledge in CPR, both because its believed to be equally efficient but also a simplified form of CPR that could lead to a higher incidence of bystander-CPR. In an initiative to increase CPR rates the American Heart Association has launched public campaigns such as the "hands-only CPR" promoting CO-CPR as an option to S-CPR for adult non-asphyxic cardiac arrest. In the 2015 updates of the European resuscitation council guidelines it states that the confidence in the equivalence between the two methods is not sufficient to change current practice. Whether CO-CPR leads to a survival rate no worse than, or even superior to standard CPR in situations where the bystander has previous CPR training remains unclear. This clinical question remains unanswered while millions of people are trained in CPR worldwide each year. To investigate whether CO-CPR is non-inferior to standard CPR (S-CPR) when performed by a bystander with previous CPR training in witnessed, non-asphyxic cases of OHCA. Superiority testing will also be performed for the purpose of demonstrating a possible increase in survival with CO-CPR.

Detailed description

This is an interventional, prospective, randomized, 1:1 open label, multicenter trial comparing two different methods of bystander CPR in witnessed cases of OHCA. Since CO-CPR is a simplified form of CPR that could lead to a higher rate of bystander-CPR by itself, a non-inferiority design for the primary outcome has been chosen. Superiority testing will also be performed to demonstrate a potential increase in survival with CO-CPR. Witnessed cases of OHCA with a non-asphyctic aetiology will be the principal study population. According to current guidelines, an unresponsive patient with no or agonal breathing is treated as a suspected case of OHCA at the dispatch centre. These cases are eligible for screening for inclusion. If the case is witnessed, the bystander has previous knowledge in CPR, and no exclusion criteria are present, the case can be included in the study. If included, it will be randomly assigned to either CO-CPR (intervention) or S-CPR (control). The intervention consists of instructions from a dispatcher at the dispatch center to bystanders to perform either CO-CPR (intervention) or S-CPR (control). * Instructions to bystanders on how to perform CO-CPR include continuous chest compressions without interruptions or rescue breaths. * Instructions to bystanders on how to perform S-CPR in the control group include information on giving chest compressions and rescue breaths in a 30:2 ratio. This is a national study where all dispatch centers in Sweden participate, and since 2025, selected sites in northern Italy. The overall study project is conducted in three different phases: 1. RUN-IN period, for establishing logistical and technical study procedures (completed) 2. PILOT STUDY, with focus on feasibility, logistics, and safety (completed) 3. MAIN STUDY will focus on 30-day survival (primary end point) and other important clinical outcomes (secondary outcomes) Objective for RUN-IN period: In order to test the technical inclusion procedures, logistics, feasibility, and data collection, a pre-study RUN-IN period started in Stockholm during 2015. Objective PILOT study: The PILOT study aimed to assess the safety and feasibility of the TANGO2 trial design, as well as intermediate clinical outcomes. The TANGO2 trial started recruitment of patients on January 1st, 2017, and the last patient was included on December 31st, 2018. All patients from the PILOT study will be included in the MAIN STUDY in a seamless design. Objective MAIN study: The MAIN study aims to evaluate whether survival to 30 days following instructions to perform CO-CPR is non-inferior to instructions to perform S-CPR in witnessed OHCA where the bystander has previous CPR training.

Interventions

OTHERChest Compression Only CPR (CO-CPR) performed by trained bystanders after instructions from dispatchers

Instructions by dispatcher to bystander to provide CPR with chest-compressions only The instructions from the dispatcher in interventional arm include: * An ambulance is dispatched and is on it´s way to you * Do CPR with chest compressions only * Push hard on the chest with a pace of 100/minute without interruptions for rescue breathing.

OTHERStandard CPR (S-CPR) performed by trained bystanders after instructions from dispatchers

Instructions by dispatcher to bystander to provide CPR with chest-compressions and rescue breaths in a ration of 30:2 The Instructions from the dispatcher in the control arm include: * An ambulance is dispatched and is on it´s way to you * Do CPR with chest compressions and rescue breathing * Push hard on the chest 30 times and give 2 rescue breaths. The pace of the compressions should be 100/minute.

Sponsors

Karolinska Institutet
Lead SponsorOTHER
Swedish Heart Lung Foundation
CollaboratorOTHER
SOS Alarm
CollaboratorUNKNOWN
Azienda Regionale Emergenza Urgenza - AREU Lombardia
CollaboratorOTHER
The Swedish Research Council
CollaboratorOTHER_GOV

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
DOUBLE (Investigator, Outcomes Assessor)

Masking description

Because of the inherent logistical problems, where the dispatcher at the emergency medical dispatch center can not be blinded to the randomized allocation (instruction), the study is defined as open-label. Treatment allocation will, however, be blinded for EMS, data management, and at follow-up, for clinicians treating the patients at the hospitals, and for all responsible researchers. Allocation concealment will be preserved.

Intervention model description

Randomized, 1:1, open-label, multicenter trial

Eligibility

Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No

Inclusion criteria

* Unconsciousness with no, abnormal or agonal breathing (suspected OHCA) * The suspected OHCA is witnessed (seen or heard) * Any Bystander at the scene has previous training in CPR

Exclusion criteria

* Age below 18 years * Collapse is not witnessed * Bystander has no prior CPR training * Obvious asphyxia (i.e. hanging, foreign body, suffocation, strangulation) * Obvious drug overdose / intoxication * Pregnancy * Trauma (penetrating, blunt, burn injury) Post randomisation

Design outcomes

Primary

MeasureTime frameDescription
30-day survival1 monthSurvival to 30 days after cardiac arrest

Secondary

MeasureTime frameDescription
1-day survival1 day1-day survival will be derived from the date of death recorded in Swedish Cardiopulmonary Resuscitation Registry (SRCR). Because SRCR only provides the calendar date of death (and not the exact time), we cannot reliably determine the Utstein variable "survival to hospital admission". We therefore will use 1-day survival as a proxy. If the SRCR date of death is the calendar day after the event date, the patient will be classified as still alive after 1-day. Separating survival to hospital admission from early in-hospital death will not be possible with the available SRCR data.
1-year survival1 yearSurvival to 1-year after cardiac arrest
Survival with good neurologic outcome at discharge30 daysSurvival to hospital discharge with cerebral performance category (CPC) 1-2

Countries

Italy, Sweden

Contacts

CONTACTJacob Hollenberg, MD. PhD
jacob.hollenberg@ki.se004686163816
PRINCIPAL_INVESTIGATORJacob Hollenberg, MD, PhD

Karolinska Institutet

STUDY_CHAIRGiuseppe Ristagno, MD, PhD

University of Milan

STUDY_CHAIRGabril Riva, MD, PhD

Karolinska Institutet

STUDY_CHAIRMartin Jonsson, McS, PhD

Karolinska Institutet

STUDY_CHAIRMattias Ringh, MD, PhD

Karolinska Institutet

STUDY_CHAIRPer Nordberg, MD, PhD

Karolinska Institutet

STUDY_CHAIRAnnette Nord, RN, PhD

Karolinska Institutet

STUDY_CHAIRAndreas Claesson, RN, PhD

Karolinska Institutet

STUDY_CHAIRMarcus Skrifvars, MD, PhD

University of Helsinki

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: May 9, 2026