A Medical Device Daily

If you’re going to have a cardiac arrest – the type best treated with an automated cardioverter defibrillator – you may assume that it’s best to have that experience, which is fatal more times than note, in a hospital.

But you know what they say about “assuming.”

Hospitalized patients are facing deadly delays in getting treatment for cardiac arrests, according to results of a new study conducted by a team from the Mid-America Heart Institute (Kansas City, Missouri) of St. Luke’s Hospital (Kansas City, Missouri) and the University of Michigan Cardiovascular Center (Ann Arbor).

The study appears this week in The New England Journal of Medicine.

An estimated 750,000 hospitalized patients experience cardiac arrest and undergo CPR annually, and less than 30% of those leave the hospital alive.

In a paper published in the Jan. 3 issue of the New England Journal of Medicine, researchers quantified the impact of defibrillation provided as therapy to hospitalized patients experiencing ventricular arrhythmia. They found that the chances of survival for hospitalized patients improve dramatically if defibrillation is administered within the expert-recommended two minute timeframe following a cardiac arrest.

Using an analysis of data from the National Registry of Cardiopulmonary Resuscitation, the authors concluded that 30% of patients with cardiac arrest due to ventricular arrhythmia received life-saving defibrillation more than two minutes after initial recognition of their cardiac arrest, a delay thus exceeding the guidelines-based recommendations.

The delayed defibrillation was linked to a significantly lower probability of survival to hospital discharge — 22% vs. 39% when defibrillation wasn’t delayed. And there was a 26% lower likelihood among survivors of being discharged without major neurological impairment.

The findings also revealed certain hospital characteristics were associated with delayed defibrillation.

These included:

• small hospital size (“small” defined as fewer than 250 beds);

• the occurrence of cardiac arrest in hospitalized patients whose heart rhythm was not being constantly monitored in specialized units;

• and the occurrence of cardiac arrest after-hours.

“While several prior studies have shown an association between defibrillation time and survival, these were relatively small studies that typically included patients whose arrest rhythms would not have benefited from defibrillation” said lead study author Paul Chan, MD, a cardiologist and researcher from Saint Luke’s Mid America Heart Institute. Chan was previously with the University of Michigan (Ann Arbor), where he initiated the study with University of Michigan cardiologist Brahmajee Nallamothu, MD, MPH, the new paper’s senior author.

The study used a larger, more statistically significant registry of nearly 7,000 patients and focused exclusively on appropriate patients with ventricular arrhythmia.

“We found that delayed defibrillation was common, and that rapid defibrillation was associated with sizable survival gains in these high-risk patients,” said Chan. “However, the real work has yet to be done in this field. We now have to develop systems of care within the hospital to improve defibrillation times nationally.”

“These findings represent a real opportunity to improve patient care,” said Nallamothu. “We need to understand how delayed defibrillation, which was more common after-hours and in unmonitored settings, relates to the immediate availability of medical personnel or equipment, as well as potential delays in recognition of ventricular arrhythmia.”

The researchers said the next step is to do studies to identify the hospoital policies, practices, equipment and personnel that ensure defibrillation therapy in less than two minutes following cardiac arrest.