Cardiologists identify delays in initiation of CPR in patients with LVADs

DALLAS – December 15, 2014 – Physicians at UT Southwestern Medical Center have identified a gap in current cardiopulmonary resuscitation guidelines and have proposed an algorithm for CPR in patients who have implanted left ventricular assist devices (LVADs).

An LVAD is a pumping device that mechanically assists the heart with moving blood throughout the body in patients who have congestive heart failure. More than 10,000 LVADs have been implanted in heart patients in the United States and that number is rapidly increasing as the incidence of congestive heart failure continues to grow.

Like anyone else, patients with LVADs can go into cardiac arrest. And that’s the point where UT Southwestern physicians recognized a couple of problems. The first problem is in identifying who is, actually, in cardiac arrest, since patients with continuous flow LVADs often do not have a palpable pulse as a consequence of the LVAD.

“If you look at all the resuscitation algorithms that have been universally accepted, you’ll find, right in the middle, ‘check the pulse,’ ” said Mark Drazner, M.D., Professor of Internal Medicine and senior author of the study. “That’s where the problem is, because with the LVAD, patients often do not have a pulse to begin with, so you can’t use the absence of a pulse to determine whether or not you need to start CPR.”

Once it has been established that the patient is in cardiac arrest, there remains the issue of whether to perform CPR on a patient with an LVAD. Could compressions damage or dislodge the device, making the problem worse? How are physicians dealing with this situation and is there confusion?

Dr. Sonia Garg, a cardiology fellow and first author on the study, tackled these questions by retrospectively examining charts of 415 patients who had in-hospital cardiac arrests during a 33-month period. Of those 415 arrests, 16 arrests, or 4 percent, occurred in patients with continuous flow LVADs.

The study found that there were significant variations in techniques used to assess perfusion in LVAD patients, and that there were significant delays in treatment of cardiopulmonary arrest in some patients who had LVADs compared with patients who did not have LVADs.

As a result of these findings and a lack of written guidelines, the physicians put together a proposed protocol for assessing and treating cardiac arrest in hospitalized patients with LVADs. Among their recommendations:

  • Medical personnel who encounter an unresponsive LVAD patient should begin by checking for device issues such as disconnected batteries or cable connections.
  • A Doppler blood flow monitor should be used to assess arterial blood flow in patients with a continuous flow LVAD. The study authors, therefore, are recommending that all crash carts carry a Doppler monitor.
  • Conditions termed “Flowless Arrest” and “Unstable Flow” are defined and recommendations are offered for treatment of each of these situations.  

“What Dr. Garg showed is that there are significant delays in starting CPR in some patients with LVADs, likely due to uncertainties about how to determine whether CPR should be attempted,” said Dr. Drazner, who is the Medical Director of the Heart Failure, LVAD, and Cardiac Transplantation program at UT Southwestern. “The LVAD numbers are growing exponentially and we feel that there is a gap in the guidelines. We put forth a proposed algorithm, recognizing that it really is just the start of a discussion.  This area definitely needs more work, and we need the help of other thought leaders in the field to address this situation, but we feel our study is a starting point.”

The study appears this month in the Journal of Cardiac Failure and the complete algorithm can be found online at www.onlinejcf.com.

Other UT Southwestern researchers who participated in this study are Colby Ayers, faculty associate; Catherine Fitzsimmons, Nurse Practitioner; Dr. Dan Meyer, Professor of Cardiovascular and Thoracic Surgery; Dr. Matthias Peltz, Assistant Professor of Cardiovascular and Thoracic Surgery and Biomedical Engineering; Dr. Brian Bethea, former Assistant Professor of Cardiovascular and Thoracic Surgery; Dr. William Cornwell, cardiology fellow; Dr. Faris Araj, Assistant Professor of Internal Medicine; and Dr. Jennifer Thibodeau, Assistant Professor of Internal Medicine. Dr. Drazner holds the James M. Wooten Chair in Cardiology.

Posted December 15, 2014