Activist investor Greenlight Capital had said the plan would "help fix GM's inefficient capital structure" and unlock significant shareholder value.
Kristi Matus of Athenahealth is on a mission to help medical practices and hospitals recast the way care is delivered.
Veteran company executive Amy Hood, known as personable and a natural collaborator, gets the nod after finance chief Peter Klein becomes the latest top manager to quit the software giant.
