British researchers led by Oxford University said on Friday that the current understanding of long COVID and options to treat it is emerging as a major long-term issue for global healthcare systems after reviewing the illness' effects on patients.

The review, published in the European Heart Journal, looked at direct impacts of a coronavirus infection such as myocardial infarction or inflammatory myocarditis - severe heart conditions - and long-term effects such as fatigue and mental wellbeing.

"Long COVID is, besides its huge impact for the affected individual, of great societal and economic importance as it leads to leave of absence from work, reduced work performance and hence unforeseen costs," said Thomas Lüscher from the Royal Brompton and Harefield Clinical Group.