Tokyo, Dec 30 : A team of Japanese researchers have predicted the risk of a "heart failure pandemic" as a result of Covid-19, stressing the need for developing countermeasures. Covid infections have raised the risk of heart failure from persistent viral infection in their hearts, even without developing heart disease, said the team, including researchers from Riken, Japan's largest scientific institute, The Mainichi reported. Post Covid pandemic, there has been a significant surge in heart attacks, even among the otherwise healthy population. Although some have linked it to Covid vaccinations, global health authorities like the WHO, US CDC, as well the ICMR have denied the association between the two. Their studies have shown that people without Covid vaccinations have been more at risk of heart problems due to Covid, and that the jabs have been safe. Coronavirus infection occurs when a protruding spike protein on the surface of the virus latches onto ACE2 receptors on the surface of human cells. The team explained that the ACE2 receptor is more common in the heart than other organs. Some Covid patients have reportedly had reduced cardiac function, but the mechanism's details are not yet known, the report said. In the study, published in the American science journal iScience, the research team first created heart tissue using induced pluripotent stem (iPS) cells. When a large amount of the virus was made to infect the tissue, cardiac function declined and did not recover. When 10 per cent of the previous amount infected the tissue, a certain level of cardiac function remained, but the infection persisted for four weeks. Researchers said it's possible that some patients won't develop heart failure even if the infection persists. Furthermore, when cardiac tissue was placed under hypoxic conditions to reduce cardiac function, uninfected cells recovered after a certain time, but cells that remained infected with a small amount of virus did not recover. It appears that their recovery ability was weakened by persistent infection, the report said. "Some people infected with the coronavirus may have persistent viral infections in their hearts. A testing system and treatment methods must be established in preparation for a 'heart failure pandemic,' in which we will see a rapid increase in the number of heart failure patients," Hidetoshi Masumoto, Riken Research Leader was quoted as saying. The findings come at a time when there is a fresh global rise in Covid infections. As per the WHO, the global number of new Covid-19 cases has increased by 52 per cent during the last one month. The UN health body also reported an increase in hospital, ICU admissions as well as deaths globally. /IANS