List Workflow Executions ignoring previous runs

From Slack:

We’re considering using Cadence to run something akin to the actor model.
We will have an actor for every “user”, of which there are tens of millions, and each actor will be in charge of processing messages for its corresponding user.
We would love to be able to query cadence for all actors that are currently in a failed state. This is a payments related use case, and its important for us to know every actor that is currently stuck.
With that, we want to filter out all actors that are no longer in a failed state. That is, if there was an actor that had a workflow execution fail, but has since had a workflow execution succeed, we consider that actor fixed, and we want it filtered out of the query.
Is there any way to do this?
If I understand correctly, a lot of the listing features that Cadence provides list workflow executions, but what I really want is to list the set of most recent executions per workflow.