THE PEARL STUDY: University of Arizona Sarver Heart Center Study on Early Coronary Angiography in Out-of-Hospital Cardiac Arrest Survivors

Información en Español

What is The PEARL Study?

A Pilot Randomized Clinical Trial of Early Coronary Angiography Versus No Early Coronary Angiography for Post-Cardiac Arrest Patients Without ECG ST Segment Elevation, called The PEARL Study for short, is evaluating the safety and effectiveness of coronary angiography (also known as heart catheterization) performed within 120 minutes of hospital arrival in a population of post-cardiac arrest patients without ST Segment elevation on their electrocardiograms (ECGs).

This study will help answer the question: “Does an early heart catheterization improve cardiac arrest survival, regardless of what the ECG shows?”

Images taken during a coronary angiogram (heart catheterization) of the coronary arteries

blocked coronary artery - reduced blood flowStented coronary artery - blood flow returned









What is cardiac arrest?

Cardiac arrest is a major public health issue and survival rates are poor. Cardiac arrest occurs when a person’s heart suddenly stops pumping blood. In adults, this often occurs following a heart attack.

  • Only 40 percent of the people who have an out-of-hospital cardiac arrest are resuscitated and brought alive to the hospital.
  • Of those 40 percent brought to the hospital, only one in four survives to go home.

If the electrocardiogram (ECG) shows changes of a heart attack, cardiac arrest patients have a coronary angiogram (heart catheterization).

When the ECG does not show an obvious heart attack, the timing of the heart catheterization is decided on a case-by-case basis by treating doctors.

Improving post-resuscitation care is an opportunity to improve chances of survival even more, once the patient arrives to the emergency department.

Who can participate? 

When patients have cardiac arrest (the heart suddenly stops beating), physicians use the ST Segment measurement from ECGs to determine if the cardiac arrest was caused by a heart attack that happened because the blood flow in an artery of the heart is completely blocked (or occluded). When the ECG does not show changes of a heart attack or complete blockage, the timing of the heart catheterization is decided on a case-by-case basis by the treating doctors.

ECG Examples of ST Segments

Normal ST Segment on ECG










About 240 patients who survive a cardiac arrest with normal ST Segments on their ECGs will be enrolled from four U.S. sites and one international site. The University of Arizona Sarver Heart Center research physicians, who are leading this multi-center study, intend to enroll 40-50 patients during a two-year period. Qualified patients brought to Banner-University Medical Center Tucson and South after a cardiac arrest will be randomly assigned (like a flip of a coin) to one of two groups.

Group 1

  • Early heart catheterization: Patients who arrive to the hospital following an out-of-hospital cardiac arrest without ST Segment elevation will receive an early heart catheterization within 120 minutes of arrival.

Group 2

  • Control Group: Patients who arrive to the hospital following an out-of-hospital cardiac arrest, with normal ST Segment on their ECG will receive standard post-arrest treatment. This means that the treating doctors will decide on a case-by-case basis whether a heart catheterization is necessary.

Both groups will be treated with the usual standard of care, including therapeutic hypothermia which is thought to protect the brain from injury due to decreased blood flow during the cardiac arrest.

Who is leading this research? 

Karl B. Kern, MD
Professor, Medicine
University of Arizona Sarver Heart Center
Cardiopulmonary Resuscitation Research Group 
Principal Investigator

“Currently only cardiac arrest patients with certain ECG findings after resuscitation (ST segment elevation) are recommended for emergent catheterization of the artery to look for blockages (coronary angiography). This study will examine if other post-cardiac arrest patients (those without ST segment elevation) might also benefit from early coronary angiography.  We believe the answer to this question is extremely important as we continue to strive to improve long-term outcomes for cardiac arrest victims,” said Dr. Karl Kern.


Kwan S. Lee, MD
Assistant Professor
Banner - University Medical Center South
Director, Cardiac Catheterization Lab

“We are excited to have Southern Arizona lead in this important national study looking at new treatments for patients with out-of-hospital cardiac arrest and the effort to further improve long-term survival,” said Dr. Kwan Lee.


Who is funding this research?
The Arizona Department of Health Services, Arizona Biomedical Research Commission awarded Dr. Kern, professor of medicine at the University of Arizona Sarver Heart Center, a three-year grant to conduct this study. Dr. Kern will lead a group of physicians at the Banner - University Medical Center, Tucson and South Campuses, and at Vanderbilt University Medical Center, Maine Medical Center, University of Minneapolis and University Medical Center Ljubljana. Dr. Kern's research also is funded in part by the Gordon A. Ewy, MD, Distinguished Endowed Chair of Cardiovascular Medicine, the Gordon A. Ewy, MD, Resuscitation Research Endowment and the Steven M. Gootter Foundation.

Study Sites Outside of Arizona:

Minneapolis Heart Institute
Principal Investigator: Michael R. Mooney, MD
Site Coordinator: David Hildebrandt
Email Address: David.

Tufts University School of Medicine, Maine Medical Center
Principal Investigator: David B. Seder, MD
Site Coordinator: Barbara McCrub
Email Address:

University of Minnesota
Principal Investigator: Demetri Yannopoulos, MD
Email Address:

Vanderbilt University School of Medicine
Principal Investigator: John A. McPherson, MD
Site Coordinator: Bobbye Wieman
Email Address:

University Medical Center Ljubljana
Principal Investigator: Marko Noc, MD
Email Address:

Exception from Informed Consent for Emergency Research?  

Because patients with out-of-hospital cardiac arrest are usually unconscious and unable to give consent to participate in the study, the PEARL Study falls under the unique Federal Drug and Administration (FDA) regulation concerning “exception from informed consent.” Such regulations are strict and the research must meet specific federal regulations and local Institutional Review Board (IRB) approval. The IRB gives the researcher the ability to enroll patients into the study when they cannot speak for themselves because of life-threatening injury or illness.

Patients who wish not to be included in the PEARL Study can request an opt-out bracelet that indicates to the investigators that the patient declines to be part of this study.

To request to opt-out of the PEARL study or for additional information about this study, please email the research team at call 520-626-5431.

Questions or concerns may also be addressed to the University of Arizona Human Subject’s Protection
Program (UA HSPP) at 520-626-5515 or email