Better Science Needed to Identify clinical predictors that link cardiac arrest, brain injury, and death

The American Heart Association (AHA) releases a statement July 11 calling for better science to support clinical predictors that link cardiac arrest, brain injury and the patient’s death. The new research findings published in the AHA’s journal Circulation note that resuscitation and post-resuscitation care after cardiac arrest have both improved but mortality remains high

Inaccurate Neurologic Prognostication Leads to Biased Clinical Studies

Most of the poor treatment outcomes and deaths of cardiac arrest survivors have been attributed to widespread brain injury, but inaccurate neurologic prognostication, resulting in withdrawal of life-sustaining treatment and deaths, may significantly bias clinical studies, the researchers say, this leading to failure in detecting the true study outcomes.

Better science needed to support clinical predictors that link cardiac arrest, brain injury, and death: a statement from the American Heart Association Photo Credit:; American Heart Associatio

The researchers note that a vast majority of patients who are successfully resuscitated from cardiac arrest are diagnosed after their resuscitation with coma or with an altered level of consciousness due to lack of oxygen to the brain before resuscitation. Most deaths associated with brain injury after cardiac arrest result from active withdrawal of life-sustaining treatment because a poor neurologic outcome is predicted. While most deaths in patients initially resuscitated from cardiac arrest are attributed to brain injury, only about 10 percent of these deaths meet clinical criteria for brain death.

The researchers say that determining prognosis after successful resuscitation is a central component of post-cardiac arrest care. Unfortunately, the quality of science that supports prediction of outcome in comatose survivors of cardiac arrest is low, they add, stressing that this low quality of science leads to error in predictions of outcomes that are likely to have a negative impact on patient care and clinical trials.

AHA’s released scientific statement provides a roadmap for how studies in the prediction of outcomes ought to be undertaken so that quality will be improved, which may result in better patient care and improvement in clinical trials. The statement also provides suggestions to improve the scientific quality of neurologic prognostication studies in comatose adult and pediatric survivors of cardiac arrest.

High Quality Science Results in Better Treatment Decisions

“At the current state of affairs, we have to acknowledge the limitations in our practices in this area because we don’t have high-quality science to back our decision-making. We owe it to patients and families to ensure we are doing the best to both not prolong unnecessary suffering while balancing that with not withdrawing care too soon if the person has the potential to recover with a reasonably good quality of life,” said Romergryko G. Geocadin, M.D., professor of Neurology at Johns Hopkins Hospital and author of the new scientific statement published in the American Heart Association journal Circulation.

AHA’s statement suggests the need to create an index test based on neurologic functions that are directly related to functional outcomes and contribute to quality of life for survivors and calls for researchers to provide summary measures of accuracy and precision for clinical studies.  Researchers should specify measures of functional outcome and cause of death differentiated as cardiovascular or neurologic.  And they should target timing of primary and secondary outcome assessments and consider prearrest lifestyle and comorbidity factors.

According to the researchers, there are about 326,200 out-of-hospital cardiac arrests and 209,000 in-hospital cardiac arrest each year in the U.S.  The survival to hospital discharge in 2016 was 12 percent for out-of-hospital cardiac arrests and 25 percent for in-hospital cardiac arrests. They note that survival with good neurologic outcome for out-of-hospital is 8 percent.