What is the best way to determine the last time a lead was updated?

I’d like access to the value displayed in the Updated column for a lead.  My understanding is getMultipleLeads does not return this date.

I see from the API documentation that getLeadChanges() provides a list of all changes to a set of leads so I assume I could derive the Updated value from that call.  However, getLeadChanges() appears to return detailed change records and seems quite heavyweight just to get the Updated date.

What is the most efficient way to get the Updated date for a list of Marketo Leads?