COVID-19 patients who suffer a cardiac arrest either in or out of hospital are far more likely to die than those who are not infected with the novel coronavirus, according to a study published on 15 January which found that women, in particular, have the highest risk.

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The research from Sweden found that women infected with the COVID-19 virus are nine times more likely to die as compared to men after suffering a cardiac arrest in hospital. The study, published in the European Heart Journal, included 1,946 people who suffered a cardiac arrest out of hospital (OHCA) and 1,080 who suffered one in hospital (IHCA) between January 1 and July 20, last year.

The researchers from the University of Gothenburg, Sweden, noted that during the pandemic phase of the study, COVID-19 was involved in at least 10 per cent of all OHCAs and 16 per cent of IHCAs. COVID-19 patients who had an OHCA had a 3.4-fold increased risk of dying within 30 days, while IHCA patients had a 2.3-fold increased risk of dying within 30 days, they said.

"Our study clearly shows that cardiac arrest and COVID-19 is a very lethal combination, said first author of the study, Pedram Sultanian, a doctoral student at the University of Gothenburg. "Patients with the coronavirus should be monitored intensively and measures taken to prevent cardiac arrest, for instance with the use of continuous heart monitors for patients at high risk," Sultanian sad.

When the researchers compared pre-pandemic cases with COVID-19 cases, they found that the overall risk of dying following an OHCA nearly tripled. It was increased 4.5-fold for men and by a third for women, they said. According to the study, the overall risk of dying after an IHCA more than doubled. It was increased by a half in men and more than nine-fold in women, the study found. The researchers also found a 2.7-fold increase in the proportion of OHCAs caused by breathing problems, and an 8.6 percent increase in compression-only cardiopulmonary resuscitation (CPR) during the pandemic. The percentage of people who were treated with both chest compression as well as mouth-to-mouth resuscitation, fell from 33 percent pre-pandemic to 23 percent during the pandemic, they said.

In March the European Resuscitation Council and the Swedish Resuscitation Council issued guidelines recommending that bystanders who see a cardiac arrest should avoid mouth-to-mouth resuscitation and concentrate on chest compressions in the case of suspected COVID-19 infection. "Although previous studies have indicated that compression-only CPR delivered by bystanders may be as effective as compressions and ventilation combined, this may not apply to cases with COVID-19, since they are primarily suffering from respiratory failure," said senior author of the study, Araz Rawshani, physician and researcher at the University of Gothenburg. "We believe this is an important finding that could possibly help authorities in handling the pandemic," Rawshani added.