(Bloomberg) — United Continental Holdings Inc. (NYSE:UAL) Chief Executive Officer Oscar Munoz had a heart transplant Wednesday, almost three months after suffering a heart attack, and is expected back by the start of the second quarter.
The operation was seen as "the preferred treatment and was not the result of a setback in his recovery," the airline said in a statement. Still, it shows the gravity of his heart condition, which hadn't previously been disclosed. Transplants are generally the last stop for patients who haven't benefited from medicines or other procedures designed to strengthen the heart.
See also: Disability insurers seek eye contact
"This is several degrees more serious than we've been led to believe," said Vicki Bryan, a debt analyst at bond researcher Gimme Credit.
Medical advances have improved the outcomes for most patients, who typically can return to work within three to six months, according to the Mayo Clinic in Rochester, Minn. Munoz's anticipated return has been pushed back slightly, as the company said earlier it expected him back within the first quarter.
"The vast majority, if they are working age, get back to work," though many are older and elect not to return, said Brooks Edwards, director of the Mayo Clinic's transplant center. "We have a number of patients that have completed one or more marathons after a transplant. It depends in large part on the patient's motivation to get back into the fast lane."
Megan McCarthy, a spokeswoman for United, declined to say where Munoz had the procedure or where he is recovering.
Munoz, 57, was hired Sept. 8 and went on sick leave after suffering a heart attack on Oct. 15. He was replaced temporarily as acting CEO by the airline's general counsel, Brett Hart. Before falling ill, Munoz had promised to improve customer relations at United. The company has had a series of positive developments with its unions, including a potential contract extension with its pilots union and a tentative contract agreement with the Teamsters-represented mechanics.