Richard Bracken, who led HCA Holdings Inc. back to being a publicly traded company and helped the company post industry-topping patient volume growth, plans to retire as CEO at year-end. Milton Johnson, a 31-year company veteran who was named president 2½ years ago and continued as chief financial officer, will assume that role. Bracken, 60, will remain board chairman, HCA said, adding an internal search is underway for a CFO to succeed Johnson in that role. Wall Street analysts expect a smooth leadership transition, adding that the change is in line with the natural progression at a company with deep management talent.