Sex-specific warning signs seen before imminent cardiac arrest: Lancet study

People experienced gender-specific warning symptoms before an imminent sudden cardiac arrest, new research published in the journal The Lancet Digital Health found.

In women, shortness of breath was the most prominent symptom of a sudden cardiac arrest about to occur, whereas in men, it was chest pain, the study led by the Smidt Heart Institute at Cedars-Sinai Medical Center, California, US, found. However, smaller subgroups of both genders were found to have palpitations, seizure-like activity and flu-like symptoms.

Further, 50 per cent of those having a sudden cardiac arrest felt at least one telling symptom such as chest pain, breathlessness, lightheadedness or irregular heart beat 24 hours prior to loss of heart function, the researchers found.

Harnessing warning symptoms to perform effective triage for those in dire need of emergency healthcare services could lead to early intervention and prevention of imminent death, the study said.

"Our findings could lead to a new paradigm for prevention of sudden cardiac death," said Sumeet Chugh, from Smidt Heart and senior and corresponding author on the study.

Out-of-hospital sudden cardiac arrest has been found to claim the lives of 90 per cent of those experiencing it, thus marking an urgent need to better predict and prevent the condition, the study said.

For this study, researchers took data from two US community-based studies, both developed by Chugh -- California-based Prediction of Sudden Death in Multi-Ethnic Communities (PRESTO) study and Oregon-based Sudden Unexpected Death Study (SUDS).

50 per cent of the 823 people, or 411 people, who had a sudden cardiac arrest witnessed by a bystander or emergency healthcare professional experienced at least one telltale symptom 24 hours previously, the PRESTO study showed. It was started 8 years ago and a total of 1672 individuals with out-of-hospital sudden cardiac arrest of probable cardiac cause had been included.

The SUDS study, initiated 22 years ago, too showed similar results, the researchers said.

"This is the first community-based study to evaluate the association of warning symptoms - or sets of symptoms - with imminent sudden cardiac arrest," said Eduardo Marban, executive director of the Smidt Heart Institute.

"Next we will supplement these key sex-specific warning symptoms with additional features - such as clinical profiles and biometric measures - for improved prediction of sudden cardiac arrest," said Chugh.

Participants' data were obtained from emergency medical services reports for people aged 18-85 years with witnessed sudden cardiac arrest (between Feb 1, 2015, and Jan 31, 2021) and an inclusion symptom, the study mentioned.

Data were also obtained from corresponding control populations without sudden cardiac arrest who were attended to by emergency medical services for similar symptoms (between Jan 1 and Dec 31, 2019), the study said.