Union Minister Murasoli Maran underwent a surgery in his heart on Wednesday night where the mitral valve was replaced some months ago.
Maran, who is under treatment in the Intensive Care Unit in the Methodist Hospital in Houston (USA), underwent the surgery as the doctors treating him felt that it was immediately necessary, a release issued from Minister of State for Health A Raja said on Thursday.
"He does not have any evidence of infection on the old heart valve, and the new valve is well seated and performing well," he said.
After the surgery, Maran's cardiac function is stable and other parameters are normal. He, however, continues to remain on ventilator.
Prime Minister Atal Bihari Vajpayee and the health ministry are closely monitoring the treatment being given to Maran, it added.