Nov. 6, 2009 announcement from the National Institutes of Health
Seattle and King County are among the nine sites across North America participating in the Resuscitation Outcomes Consortium (ROC). The consortium is supported by the National Heart, Lung, and Blood Institute (NHLBI) and was created to evaluate promising new therapies for cardiac arrest and life-threatening trauma, which are begun before hospital arrival.
Since August, 2007, the consortium has been evaluating two therapies for treating cardiac arrest in a trial called ROC PRIMED trial (Prehospital Resuscitation using an IMpedance valve and Early versus Delayed rhythm analysis). The two therapies were: (1) use of a device intended to improve CPR, and (2) determining whether a very brief or longer period of CPR before checking the heart rhythm and administering a shock to the heart would be beneficial. The device (called an impedance threshold device or ITD) is intended to bring more blood into the heart during chest compressions. The CPR protocol compared initiating resuscitation with a short period of CPR (about 30 seconds) with a longer period of CPR (about 180 seconds) before checking the heart rhythm for the first time. The trial was scrutinized by various regulatory bodies both nationally and locally, including the Federal Food and Drug Administration (FDA), an independent Data Safety and Monitoring Board (DSMB), and the University of Washington Institutional Review Board (IRB), before it was allowed to begin, and has had ongoing oversight by these bodies during its course.
In October, 2009, an independent panel of experts (DSMB), who had been regularly monitoring the trial, evaluated information that had been collected through September 15, 2009. They found that none of the treatments or treatment combinations could be said to be better than the other in further improving survival and brain function at the time of discharge from the hospital. In fact, survival in all treatment groups was higher than investigators expected, suggesting that outcome was improved in all patients. The trial was stopped because enrolling more patients would not change these results. There were no concerns about safety or adverse effects from treatment in any group of patients that received these study interventions. Further analysis of the data is ongoing and will be published once it is complete.
The results of this trial testify to the great care taken to insure effectiveness and safety when studying important problems like cardiac arrest, where emergency conditions require providing treatment before consent for them can be obtained. In this case, outcomes were better than expected in all the treatment groups, and the study was stopped because it was felt there was no longer any point in continuing to test these treatments.
Information obtained from this trial will help shape with greater certainty how future patients with cardiac arrest are best treated.
For details, read the NIH press release>
Overview
THIS IS A STUDY IN WHICH YOU CAN BE ENROLLED WITHOUT YOUR CONSENT
Cardiac arrest is the sudden, abrupt loss of heart function. Death usually occurs within minutes unless cardiopulmonary resuscitation (CPR), rapid defibrillation, and paramedic interventions are available. CPR consists of pumping on the patient’s chest and delivering breaths to produce some circulation until the heart can be restarted. When the chest is compressed, oxygen-rich blood is pumped forward. When the chest is released, oxygen-poor blood is brought back to the heart and lungs where it can be restored with oxygen before being pushed out to the body with another compression. Both actions – pushing oxygen-rich blood forward and bringing oxygen-poor blood back to the heart and lungs - are important. CPR however produces only about 30 percent of normal circulation. Methods to improve the circulation produced by CPR may lead to better survival.
Impedance Threshold Device (ITD)
One experimental device, called an impedance threshold device, or ITD, is being studied in this clinical trial. The ITD is a device smaller than your fist that attaches to the end of the breathing bag used by EMTs and paramedics. The ITD works to bring more oxygen-poor blood back to the heart so that ultimately more oxygen-rich blood is available to be pushed forward.
CPR
The timing of the CPR compressions is also being studied in this trial. Some evidence indicates that the period right before the heart is shocked may be especially important for the heart to have the best chance to regain its own natural heart beat. Experts have long believed that the first priority when trying to restart the heart was to shock the abnormal heart rhythm. More recently however some evidence has indicated that CPR should be the priority before delivering the shock. The research indicates that delaying the shock a few minutes to provide CPR may actually help the heart. The CPR seems to prime the heart pump so that after a few minutes of CPR the shock is more likely to produce a natural heartbeat than if the heart was shocked right away.
A study is planned involving the Emergency Medical Services of Seattle and King County to evaluate whether either of these strategies – the ITD or priming the heart with CPR before the shock – will improve survival following cardiac arrest. The study is entitled ROC-PRIMED (Resuscitation Outcomes Consortium Pre-hospital Resuscitation using an Impedance threshold device and Early versus Delayed rhythm analysis), is supported by the National Institute of Health and will involve 10 communities from across the United States and Canada. Seattle and greater King County are one of the 10 communities. Although these approaches appear promising and safe, they are yet to be proven to save lives.
Contact
If you still have questions after reviewing the web site, please contact us via e-mail at kcroc@u.washington.edu (note that the confidentiality of e-mail communications cannot be guaranteed) or at 206.447.5671 where you will be able to leave a voice message. The e-mail and voice mails are checked regularly, and you can expect to receive a reply within three days.