Out-of-hospital heart attacks almost doubled during the height of the coronavirus in Paris, according to a new study that raised concerns over the indirect impacts of the pandemic and contagion fears.
Research published this week in the journal Lancet Public Health by experts form France's Inserm research institute found that heart attacks surged and then decreased in tandem with the growth and subsequent fall in hospital admissions for COVID-19 in the city.
Survival rates also fell, which the authors said could be down to a reluctance to resuscitate a potentially infected person by witnesses and emergency responders -- given rules issued by some hospitals banning the procedure without proper protective equipment.
The study found that people with confirmed or suspected infection with the virus, which can affect the heart, only accounted for approximately a third of the increase during the six-week period.
For those without the virus, the authors said the rise could be caused by a number of factors linked to the pandemic.
"With lockdown and movement restrictions, patients have more difficulty in seeking medical advice. They might also be reluctant to present to emergency departments or doctors' offices because of fears of COVID-19 infection, or long waiting times," they said.
Psychological stress like fear or the loss of loved ones "can also potentially trigger adverse cardiac events", they added.
Researchers compared heart attack cases in greater Paris that were not obviously caused by an accident during the pandemic peak -- March 16 to April 26 -- with official data on the comparable period in the previous eight years.
They found that the maximum weekly incidence of out-of-hospital cardiac arrest increased from 13.4 to 26.6 per million inhabitants, before returning to normal in the final weeks.
A higher proportion of heart attacks were recorded at home (90.2 percent compared with 76.8 percent) in the period, which coincided with strict lockdown measures in the city, while the proportion of cases where bystanders intervened fell from an average of 63.9 percent in previous years to 47.8 percent.
The authors also noted a "drastic reduction" in survival to hospital admission, down from 22.8 percent to 12.8 percent.
In a commentary also published in the Lancet Public Health, Gavin Perkins and Keith Couper of Warwick Medical School noted that similar increases in rates of out-of-hospital cardiac arrests had been noted during the pandemic in Italy's badly-hit Lombardy region, and in California as well.
They called for more studies into the longer term effects the pandemic may have on people's willingness to resuscitate.
"There is a risk that the COVID-19 pandemic could undo the substantial progress that has been made in optimising the community response" to out-of-hospital cardiac arrest, they said.