New York, May 10 (IANS): Hospitalised Covid-19 patients with an often undetected sign of heart failure were nearly five times more likely to die, according to new research.

The study showed Covid-19 patients with a first-phase ejection fraction -- a measure of the left ventricular ejection fraction until the time of maximal ventricular contraction -- of less than 25 per cent had a nearly five-fold higher risk of death than those with an ejection fraction of 25 per cent or higher.

The team also found that a similar proportion of people with similar risk factors who did not have Covid-19 had low values of first-phase ejection fraction. This suggests that the damage to the heart may be due to chronic pre-existing conditions and was not the result of Covid-19 infection, the researchers said.

"Traditionally, heart function is measured by ejection fraction, or how much blood the left ventricle pumps out with each contraction of the heart," said Phil Chowienczyk, Professor of cardiovascular clinical pharmacology at St Thomas' Hospital, in London.

"First-phase ejection fraction is a new measure of the heart's function that seems to be much more sensitive of early, undetected damage to the heart than traditional ejection fraction measures," he added. The findings are published in the journal Hypertension.

Cardiovascular risk factors and/or disease have been recognised as Covid-19 risk factors that have a high negative impact on patient outcomes, since early in the SARS-CoV-2 pandemic. Researchers hypothesised that predisposition to heart failure would be associated with more severe cases of Covid-19 in hospitalised patients.

The team analysed mortality rates for 129 hospitalised Covid-19 patients in Wuhan, China, and 251 hospitalised Covid-19 patients in South London, treated between February and May 2020.

"The findings suggest that if we can prevent the very early chronic damage to the heart detected using first-phase ejection fraction imaging, then people will be much more likely to survive respiratory infections like Covid-19. Healthy lifestyle choices, better treatments and adherence to treatments for high blood pressure and high cholesterol are also important," Chowienczyk noted.