Actor Sylvester Stallone's son Sage Stallone's cause of death has been ruled a heart attack. The Los Angeles County Coroner, who had delayed the release of the toxicology reports prior, said on Thursday that the 36-year-old had been suffering from heart disease, as he been diagnosed with a blockage of the arteries.

Sage Stallone was finally laid to rest on Saturday, July 21. The funeral was held in Los Angeles, EW reports. His mother, Sasha Czack, and father, Sylvester Stallone, were among those at the private burial at St. Martin of Tours Catholic Church in Brentwood.

Still under intense investigation, the cause Sage Stallone’s death is still a mystery. However, Sasha Czak, Stallone’s mother has finally come forward with new details on her 36 year-old son’s passing. According to Czack, her late son had severe and extensive dental work done two weeks prior to his passing, in order to remove 5 teeth. She claims that she urged him against such a drastic one day procedure.

Sage, son of Sylvester Stallone and Sasha Czack, was found dead on July 13. However, latest reports suggest that the 36-year-old could have been lying dead undiscovered for over three days. As details emerge about his sudden death, law enforcement officials are saying that the actor could have been dead for as long as a week, according to TMZ.