Aviation United CEO Munoz gets heart transplant By Robert Silk / January 06, 2016 Share 1 -- Oscar Munoz United Airlines CEO Oscar Munoz underwent a heart transplant Wednesday. “A transplant was considered the preferred treatment and was not the result of a setback in his recovery,” United said in a brief announcement Wednesday evening. “The United team wishes Oscar well during his recovery and expects him to return to United at the end of the first quarter or the beginning of the second quarter.”Munoz has been on leave since suffering a heart attack in October, less than six weeks into his tenure atop the airline. In his absence, United general counsel Brett Hart is serving as acting CEO. United said it will provide additional information about Munoz in the next day. The airline had said in November that Munoz would return to the job during the first three months of this year.