The chief executive of Leeds Teaching Hospitals Trust is to leave next month. Maggie Boyle’s departure follows persistent performance problems at the trust, and an investigation into mortality rates among children undergoing heart surgery.

The trust has said it will not comment on whether Ms Boyle, a former nurse who had been chief executive for six years, resigned or was asked to leave, or whether she will be working her notice period. It said arrangements would be made to cover the post until a permanent appointment was made.

The trust’s foundation trust application was recently escalated by the NHS Trust Development Authority after concerns that the submitted plan – described by the trust as a “work in progress” - did not deliver all performance targets throughout this year and only predicted breakeven for 2013-14.

Last month’s board papers say a meeting between the NHSTDA and the trust to discuss this was planned for May 8. A timescale for becoming an FT was also to be discussed this month. There had been no agreed trajectory for the trust.

The board papers show the trust had been below the four hour target in A&E since October with performance in March below 88 per cent. Although it was hitting the 90 per cent referral to treatment target for admitted patients in February and March, this had been at the expense of increasing the backlog of long waiters – something the trust was proposing to address through increased activity.

Ms Boyle’s chief executive’s board report admitted: “Our performance has been below expectations all quarter. Specifically our A&E performance continues to be of the greatest concern.”

She added that it had been “this year we have achieved a significantly lower surplus than we had planned for”. The board papers suggest the end position for 2012-13 will be between breakeven and a surplus of £1.5m.

The trust had considered setting a £10m surplus target for 2013-14 but had decided this was not achievable and had agreed to aim for breakeven, even though this would not meet the requirements for aspirant FTs. However, it still has to identify £13.5m in savings to reach this and would need additional public sector borrowing to make capital investments it says would improve performance and quality.

The announcement of Ms Boyle’s departure also comes several weeks after children’s heart surgery at the Leeds General Infirmary was temporarily halted after data suggested its mortality rate was above other units doing similar work. Operations restarted after a high profile investigation involving NHS England medical director Professor Sir Bruce Keogh, and it was ultimately declared to be safe.

In a statement issued by the trust, Ms Boyle said: “It has been a pleasure and a privilege to be Chief Executive at LTHT over the past six years. I believe the move to new management arrangements which will see a clinically led, managerially supported structure being established is absolutely the right thing to do and will have enormous benefits for patient focused care delivery.

“I would like to wish the senior leaders and all of their staff all best wishes for a successful future.”