Calvin Harris was forced to pull out of tonight's (09.11.14) MTV European Music Awards because of a heart scare.

News that Calvin, 30, would not be appearing at the much-anticipated event in Glasgow was revealed by event organisers, who only offered a vague reason as to why the world's top earning DJ would not open the show as planned.

However, Calvin has elaborated on the problem, telling his Twitter followers: ''No EMAs for me this weekend. Got some heart problems. Heading home to see if it can be fixed x. (sic)''

The late decision to withdraw from the show creates a real problem for its organisers, who've had to make some last-minute adjustments.

A source told the Mirror newspaper: ''Obviously everybody wishes Calvin all the best for a speedy recovery - but it will take a lot of reorganisation.''

The show is being hosted by Nicki Minaj, who admits she's anxious about the responsibility.

The 'Superbass' hitmaker said: ''I was having a lot of anxiety yesterday actually because I know there is a lot of pressure and it's a big job and I always want to give my best and be amazing.

''After I rehearsed yesterday I felt a lot better - it's going to be a really, really fun show.''