Flu circulating in Russia can cause a heart attack or stroke This year, Russians risk contracting the Hong Kong flu virus, which has risks of complications. It is especially dangerous for people with chronic heart diseases, warned general practitioner Nadezhda Chernyshova in an interview with AiF. "Hong Kong flu is usually more severe and has more cardiovascular complications. In this case, more severe intoxication, body aches, muscle pains and a high temperature of 40 degrees are more often observed. In older people, complications often lead to heart attacks and strokes," explained the doctor. Many people around you have already had the flu or ARVI? - Yes - No.