November 5, 2013
Commissioner Margaret Hamburg
Food and Drug Administration
10903 New Hampshire Ave
Silver Spring, MD 20993-0002
Re: FDA Circulatory Systems Devices Panel on Reclassification of External Cardiac Compressor Devices
Dear Commissioner Hamburg,
We are writing to express our strong concerns about the September 11, 2013 FDA meeting of the Advisory Committee for Circulatory System Devices. This Advisory Committee meeting discussed and made recommendations regarding the proposed down-classification of External Cardiac Compressor (ECC) devices.
The panel members were asked to consider the FDA recommendation that ECC devices be reclassified from Class III (high risk) to Class II (moderate risk) with special controls.
Although every member of the panel had technical expertise in either cardiovascular care, circulatory system devices, or epidemiology, only one member present, Dr. Paul Pepe, had Emergency Medical Services (EMS) field experience. Unlike most cardiac devices, ECCs are used almost exclusively in the pre-hospital setting, most of the time by emergency medical personnel who are rarely physicians. For that reason, the Advisory Committee should have included members who have experience with the tremendous logistical challenges that are unique to performing CPR in a pre-hospital setting.
As an example of why that perspective was needed is the panel’s discussion of using the ECC devices as an “adjunct” to manual CPR. The FDA recommendation as presented on its slide at the meeting, states: “External cardiac compressor devices are used as an adjunct to manual cardiopulmonary resuscitation (CPR) during patient transport, extended CPR when fatigue may prohibit the delivery of effective/consistent compressions to the victim, or when insufficient EMS personnel are available to provide effective CPR.” The panel discussed the fact that there are no published studies on the use of ECCs as adjuncts when responders are fatigued or when there is insufficient personnel. The one large, well-powered randomized controlled clinical trial presented, called the ASPIRE study, only compared ECCs to manual CPR, but did not look at ECCs as an “adjunct.” However, in that study, patients receiving ECC were significantly more likely to have brain injury and were marginally significantly less likely to survive long enough to be discharged from the hospital.
It is also notable that the ASPIRE trial and most of the other studies collected data before the major revision to the American Heart Association CPR guidelines that required a re-education of all EMS providers. This major change in AHA guidelines, made in 2010, from “A-B-C” (Airway, Breathing, Chest Compressions) to “C-A-B” (Chest Compressions, Airway, Breathing) was made so that quality chest compressions could be delivered sooner.1 So, the ASPIRE trial and other studies were not comparing ECCs to the current gold standard of CPR. It would be expected that manual CPR is more effective today than it was when ASPIRE and the other studies were conducted. If so, ECCs would be expected to be even less effective compared to manual CPR today than it was in those studies.
The lack of data from controlled clinical studies comparing manual CPR, as implemented today, with ECCs as an adjunct treatment makes it virtually impossible for the FDA to conclude that there is reasonable assurance of safety and efficacy supporting the adjunct use of ECC devices. In addition, using ECCs as an adjunct is complicated and would be very difficult to evaluate in a study. For example, an ECC device requires time for at least one staff person to set up and properly apply to the patient, so using them as an adjunct in a situation where there is only one rescuer may necessitate a break in compressions. And, as EMT Maura Duffy brought up in her testimony, it is likely that if ECC is available, it will be used in cases other than when an EMT is too fatigued to perform adequate compressions. EMS crews are often eager to use the new, “sexy” equipment on the ambulance. If given the choice, emergency responders may be over-eager to automate compressions, so it is crucial that the FDA make sure that each new version of these devices works safely and effectively before they are stocked on ambulances.
During the panel discussion, when a question related to logistical aspects of performing CPR on an ambulance arose, Dr. Paul Pepe was the only one available to give emergency responder provider experience. Dr. David Yuh asked a question of Dr. Paul Pepe and of Maura Duffy, who had spoken during the public comment period, but Dr. Bram Zuckerman of the FDA stated that questions should only be asked of panel members during panel deliberations (see page 107 of transcript: http://www.fda.gov/downloads/AdvisoryCommittees/CommitteesMeetingMaterials/MedicalDevices/MedicalDevicesAdvisoryCommittee/CirculatorySystemDevicesPanel/UCM371908.pdf). This was particularly unfortunate, since previously the panel had asked questions of industry representatives who spoke during the public comment period.
At one point, Dr. Borer expressed concerns that there is no scientific evidence for some of these “real world” concerns that were brought up. He is correct, and as a result of the lack of scientific data, anecdotes became a major topic of discussion. Dr. Keith Allen gave a hypothetical example of an EMT working alone in the back of an ambulance in a rural area with a long transport time to the hospital as a justification for the need of ECCs, despite the lack of any relevant scientific evidence. While there were no perspectives from emergency medical providers given during the panel discussion, and the “real world” concerns were dismissed as unscientific, the image of a famer collapsing in a field was discussed as if it were a major public health problem that could be solved by ECC devices (see page 137 of transcript). In fact, this anecdote again indicated the lack of understanding of panel members of the EMT experience: by the time an ambulance arrives in that remote rural setting, it is likely to be too late.
Although this was not a voting committee meeting, an informal straw poll of 12 of the 13 panelists was taken at the end of the session. (Dr. Paul Pepe, the one EMT on the panel, left the meeting before the vote was taken). Ten of 12 expressed support for reclassification of ECCs as Class II devices with special controls. Some of the members in favor of reclassification emphasized a need for adequate labeling and post-market surveillance studies. Since the approval is intended to be as an adjunct to manual CPR, we question whether MAUDE reports could provide useful information, and whether post-market studies are even possible –and how many decades it would take to complete them.
This unofficial vote in favor of Class II with special controls did not seem to be based on scientific evidence or any evidence of a public health need for ECCs. The strongest randomized controlled clinical trial indicated that ECCs were inferior to manual CPR, and other studies indicated that ECCs were no better than manual CPR.
Even with the proposed special controls, the reclassification from Class III to Class II would mean that no proof of safety and efficacy based on short-term clinical trials would be required. Since post-market studies cannot be required as part of a 510(k), there will be no research on these devices. Without the requirement of a PMA, companies will never have to provide reasonable assurance of safety and effectiveness for these devices, or compare specific ECC devices to each other.
We urge the FDA to bring together a group of EMTs to meet with FDA scientists and officials who will make the final decision on ECCs. We would be glad to assist in this effort.
Dr. Diana Zuckerman, President
National Research Center for Women & Families
Lisa M. Tate, Chief Executive Officer
- American Heart Association. Highlights of the 2010 AHA Guidelines for CPR and ECC. http://www.heart.org/idc/groups/heart-public/@wcm/@ecc/documents/downloadable/ucm_317350.pdf. Accessed October 29, 2013. ▲