Shiv Sena executive president Uddhav Thackeray on Sunday underwent an angioplasty procedure at Lilavati Hospital in suburban Bandra.
Sena spokesman and Rajya Sabha member Sanjay Raut told PTI that the angioplasty was done and Uddhav's health was fine.
"He is okay now," Raut said.
This was the second phase of the procedure after the 51-year-old leader had undergone the first angioplasty operation in the same hospital in July, following complaints of severe chest pain.
Doctors had discovered multi-vessel blockages in his heart and suggested that he undergo two series of medical procedures.
"Today's second angioplasty had been advised when he was admitted for the first surgery," Sena sources said.
Uddhav's wife Rashmi and children Aditya and Tejas accompanied him to the hospital early this morning.
His estranged cousin and MNS chief Raj Thackeray was also present.