Emergency Medicine


ACCESS Clinical Trial

The ACCESS Trial is a national, multi-center research study funded by the National Institutes of Health’s National Heart, Lung and Blood Institute. IU School of Medicine is one of more than 20 participating sites, led by the University of Minnesota. The study aims to determine the best method of care for survival and neurological recovery for patients resuscitated after cardiac arrest due to ventricular fibrillation (VF) outside of the hospital, but who have no evidence of a heart attack on a heart scan, called an electrocardiogram (ECG).

Sudden cardiac arrest occurring outside of the hospital setting is the third leading cause of death in the United States. It is an immediate electrical malfunction (arrhythmia) of the heart. This event disrupts heart pumping, which in turn stops blood flow to the rest of the body.

Eighty percent of cardiac arrest survivors suffer cardiac arrest due to arrhythmias known as ventricular tachycardia (VT) or ventricular fibrillation (VF). VT/VF cardiac arrests have the highest survival rate and the greatest opportunity for improvement in treatment and health outcomes for this devastating public health problem.

Why study VF arrest without evidence of heart attack on electrocardiogram?

Of the estimated 120,000 to 130,000 VT/VF cardiac arrests each year, 70 percent of these patients do not show a heart attack on electrocardiogram. Previous research has shown that this group may be likely to have a clot in their heart arteries but not have signs of a clot on their electrocardiogram (acute coronary occlusion). Other patients that show signs of a clot on their electrocardiogram are immediately taken to the cardiac catheterization laboratory for an invasive procedure (called “catheterization”) to remove the clot and restore blood flow to their heart. Despite these current research findings, a wide variation of clinical practice exists in the U.S.—varying widely from hospital to hospital.

A preliminary pilot study shows the benefits of early access to the catheterization laboratory for patients with VT/VF cardiac arrests. The ACCESS Trial is the first randomized clinical trial of its kind to study VT/VF cardiac arrest patients to provide reliable data on which clinical practice can be based and consistently provided. The trial will study two standard care approaches to the treatment of resuscitated VF cardiac arrest patients:

Initial transport to the catheterization laboratory

Initial transport to the Intensive Care Unit (ICU) for consultation by a cardiologist who then makes a decision whether or not to transport to the catheterization laboratory

Study Goals

The ACCESS trial intends to show that VT/VF cardiac arrest is a strong predictor of an underlying and correctable cardiac condition. The trial also hopes to show that initial catheterization laboratory admission results in significantly improved functionally favorable survival compared with current practices.

Trial-Related Terms

Sudden cardiac arrest is an electrical malfunction of the heart that is immediate and unexpected. This loss of heart function disrupts its pumping, which in turns stops blood flow to the rest of the body.

Sudden cardiac arrest is not necessarily a heart attack. A heart attack occurs when a blockage in the arteries supplying the heart limits blood flow to a portion of the heart. However, a heart attack can trigger an electrical malfunction that leads to sudden cardiac arrest.

If not treated immediately, sudden cardiac arrest can cause sudden cardiac death. Beginning cardiopulmonary resuscitation (CPR) or chest compressions can improve the chances of survival until emergency personnel arrive.


The resources found here can be used to learn more about cardiac arrest and heart attack. Some resources may have information on how to potentially prevent cardiac arrest while others offer support to those who have suffered from cardiac arrest. These are publicly available educational resources and are not associated with the Indiana University School of Medicine.