Heart bypass patients in Barnet face a lottery for treatment according to new figures.

Patients in the borough are more than twice as likely to die at some NHS heart units than at others according to The Hospital Guide published by healthcare specialists Dr Foster.

The Royal Free had a death rate of 1,971 per 100,000 but the University College London Hospital (UCLH) had a death rate of 4,028. Barts and The London Hospital's rate was 2,459.

But the Society of Thoracic Surgeons (STS) claimed that the data could be misleading.

A spokeswoman for the UCLH mirrored its concerns. "We share a surgical team with the Royal Free and all the complex cases that the team performs come to our trust."

She added: "In terms of the validity of the data, we will have to look into that and it can't be done within a day."