A former military doctor has died of complications from a heart attack at a Washington, D.C., hospital, the U.S. Department of Health and Human Services said Monday.

Dr. John C. Anderson, 63, died Monday morning at Johns Hopkins Hospital, according to the agency.

Anderson, who also served as a military doctor and retired in 2017, had been admitted to the hospital on March 23 for a “mild transient cardiac arrhythmia,” the department said in a statement.

He died a few days later.

Anderson had been hospitalized since March 15, when he became ill after returning from a tour in Japan.

His health was improving, but complications arose from the cardiac arrhmts.

Anderson suffered a stroke on May 2 and died a week later.

His funeral was Tuesday in Washington, where he was a professor of medicine at Johns Johns Hopkins University.

He was the first medical doctor to be awarded the Medal of Honor for saving the life of an American prisoner of war.