Running leases stop (suspend) the vApp when they expire.
Page 37 - VCloud Users Guide - http://www.vmware.com/pdf/vcd_15_users_guide.pdf
Joe Keegan also has a blog post on this - http://infrastructureadventures.com/2012/07/22/vcloud-director-policies-part-1leases/
That all said, what are you wanting to do? the purpose of a running lease it to make sure users can't run a vApp forever without having to checkin once and a while to say they still need it. The suspend is done so that memory state is not lost. (If you don;t want this state, VCD 5.1 has a method to delete the suspended memory state via the API - could watch for apps to expire then clean them up via VCO)