The procedure would be performed on the 52-year-old leader at Lilavati Hospital in suburban Bandra where he had undergone an angiography four days ago.
There were reports that the Lilavati medical team had strongly recommended a bypass surgery as angiography had shown three blockages.
The doctors had briefed Uddhav's father Balasaheb Thackeray on Monday on his son's medical condition.
At the time of angiography, Uddhav's estranged cousin, MNS chief Raj Thackeray, had visited him at Lilavati and later drove him to Matoshree bungalow, the Thackeray family home in suburban Bandra.
This led to speculation in the political circles about a political reconciliation between the warring cousins but Sena sources said there was no politics involved.
Raj is expected to be present at the hospital tomorrow too.
