cardiac arrest

Adults with abnormal heart metabolism are up to three times more likely to experience life-threatening arrhythmias (an irregular heart rhythm), according to a small but rigorous study led by Johns Hopkins Medicine researchers, and MRI techniques could be used to detect the condition and predict future sudden cardiac death (SCD).

“We think this is the first time that poor cardiac metabolism in individuals has been related to an increased risk of life-threatening arrhythmias or sudden cardiac death,” says research senior author and Johns Hopkins University School of Medicine professor of medicine Robert Weiss, M.D.

“This might pave the way for a whole new technique, a metabolic method for treating or avoiding severe arrhythmias, which is now unavailable in cardiology.” According to the American Heart Association, sudden cardiac death accounts for 50% of all cardiovascular fatalities in the United States, taking more than 300,000 American lives each year. Currently, the primary approach of avoiding SCD in high-risk individuals is an implanted cardioverter-defibrillator (ICD) – a tiny, battery-powered device put in the chest to detect and halt abnormal heart beats. The gadget continually monitors the heart rhythm and, if necessary, delivers electric shocks to restore a normal heart rhythm. An ICD’s battery life is normally five to seven years.

“Over a seven-year period, 60 percent to 70 percent of these devices never discharge to save a life,” says T. Jake Samuel, PhD, the study’s first author and a fellow in cardiology at Johns Hopkins Medicine. “We spend billions of dollars each year on implanted ICDs with procedural and postprocedural dangers. Noninvasive techniques to determining who requires or does not need an ICD to avoid sudden cardiac death in persons are needed.”

Samuel and colleagues evaluated adenosine triphosphate (ATP), the basic chemical cellular energy source, in the hearts of 46 persons before they received an ICD for primary prevention.

To establish whether patients had aberrant ATP metabolism, cardiac ATP levels were evaluated on clinical magnetic resonance imaging (MRI) scanners using a magnetic resonance spectroscopy (MRS) technology developed at Johns Hopkins Medicine by Paul Bottomley, PhD, a co-author of the work. For an average of ten years, all patients were followed up on every three to six months to assess whether patients had appropriate ICD firings for life-threatening arrhythmias.

People with low cardiac ATP levels (impaired metabolism) had a three-fold greater risk of sudden cardiac mortality (if not spared by ICD intervention) than those with normal ATP metabolism, according to the findings.

When corrected for low left ventricular ejection fraction, the parameter presently used to establish the requirement for a primary prevention ICD, this remained true.

“The ICD was never required in around 80% of patients with normal cardiac ATP levels over the research period,” Samuel and colleagues write. According to the researchers, the study findings might supplement current methodologies and lead to better forecasts of who will or will not require an ICD. They emphasise, however, that further research is needed to analyse diverse and bigger groups.

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“But we’re delighted about these very novel discoveries, possibly the first in humans, and feel they can revolutionise how clinicians estimate the risk of sudden cardiac death,” Weiss adds.

“Once we’ve established that metabolism and SCD are connected, we intend to investigate which medications retain and improve ATP metabolism and if they may be utilised to lower SCD risk.”

In addition to Weiss, other Johns Hopkins University School of Medicine researchers include T. Jake Samuel, Michael Schar, Katherine Wu, Angela Steinberg, Mark Anderson, Gary Gerstenblith, and Paul Bottomley; An-Chi Wei from National Taiwan University in Taipei, Taiwan; and Gordon Tomaselli from Albert Einstein College of Medicine in the Bronx, New York.

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Patients who survive a heart attack and sudden cardiac arrest have a higher chance of dying within six years after being discharged from the hospital.

According to new research published today in the Journal of the American Heart Association, this is the case.

When blood supply to the heart is impeded, a heart attack occurs, and sudden cardiac arrest occurs when the heart malfunctions and ceases pumping unexpectedly. If not treated quickly, cardiac arrest can be deadly.

The majority of heart attacks do not result in cardiac arrest. However, heart attack is a common cause of abrupt cardiac arrest.

The study uses data from 13,444 patients gathered between 2010 and 2017 by researchers from the National Institute of Health Research Health Informatics Collaborative (NIHR-HIC), which is directed by Imperial College Healthcare NHS Trust and Imperial College London. The Imperial Biomedical Research Centre of the National Institute for Health Research (NIHR) financed the research (BRC).

It demonstrates for the first time that individuals who had heart attacks followed by sudden cardiac arrest were more likely to suffer problems. Those who experienced a cardiac arrest at the time of their heart attack were twice as likely as those who only had a heart attack to develop ventricular arrhythmia (abnormal heart rhythms) (VA).

Arunashis Sau, the study’s first author and a Clinical Research Fellow at Imperial College London, said further:

“This is the first research to discover a relationship between heart attacks and abrupt cardiac arrests, as well as early mortality after surviving the first episode. Our results have major consequences for this patient population and how we treat them. The study begs the question of what else we may do to enhance these patients’ outcomes by perhaps providing more therapy alternatives.”

Doctors treat heart attack patients by unblocking coronary arteries and prescribing beta blocker medications to help the heart calm down. Patients who have a cardiac arrest are given a defibrillator, which is a device that delivers a high-energy electric shock to re-start the heart.

Previous research has revealed that individuals who suffer a heart attack and then have a sudden cardiac arrest may be a subset of people who are more likely to develop problems like VA.

These trials, on the other hand, have inadequate long-term patient follow-up data and are substantially smaller.

Researchers wanted to look into it.

The goal of the study was to look at the long-term effects of abrupt cardiac arrest on heart attack patients.
They looked studied the medical records of 13,444 heart attack patients who were admitted to and released from five NHS Trust hospitals in England. They were followed up on for three years on average. A total of 280 individuals survived a heart attack or cardiac arrest and were released.

They discovered that these patients were more than twice as likely to have VA at a later date. They also discovered that compared to individuals who had a heart attack but not a cardiac arrest, there was a 36% increase in death within three years after discharge.

Further study is needed to completely determine how to lower the risk of recurrent VA in this population, as well as whether an ICD should be considered for patients who arrive with cardiac arrest and a heart attack, according to the researchers.