Mr Srivastava has not regained consciousness for the last 46 hours.
Prime Minister Narendra Modi today called comedian and Uttar Pradesh Film Development Council chairman Raju Srivastava's wife to enquire about his health and offered support, sources from Mr Srivastava's family said.
The comedian is still on a ventilator and his condition has not yet improved, they said in the morning. He is being treated under the supervision of senior doctors of AIIMS.
Mr Srivastava has not regained consciousness for the last 46 hours.
However, his nephew said earlier this evening that his health was improving. He was being fed milk through a tube and responding to treatment, the doctors had reportedly informed the family, adding that he will take a few more days to regain consciousness.
Following a heart attack on Wednesday, the 58-year-old stand-up comedian was admitted to the hospital where he underwent angioplasty.
"He is critical and on a ventilator in the ICU," hospital sources had said.
He had visited Delhi for four-five days right before his health deteriorated.
Raju Srivastava was taken to AIIMS due to sudden chest pain while exercising on the treadmill at the Cult gym in Delhi's South Extension. He has been undergoing treatment since.
Prime Minister Narendra Modi, Defense Minister Rajnath Singh, and Uttar Pradesh Chief Minister Yogi Adityanath have spoken to the family of Raju Srivastava to enquire about his condition.
Raju Srivastava, who has been active in the entertainment industry since the late 1980s, received recognition after participating in the first season of the stand-up comedy show "The Great Indian Laughter Challenge" in 2005.
He has appeared in Hindi films such as "Maine Pyar Kiya", "Baazigar", "Bombay to Goa" (remake) and "Aamdani Atthani Kharcha Rupaiya". He was one of the contestants on "Bigg Boss" season three.