NEW YORK — Ivana Trump died Thursday of injuries from an accident inside her Upper East Side apartment, a spokesperson for the city Medical Examiner’s office confirmed Friday. The 73-year-old’s cause of death was blunt impact injuries to the torso, the spokesperson said. Trump fell down the stairs in her home, a police official said earlier this week. The ex-wife of former President Donald Trump was last seen Wednesday afternoon. The couple had three children, daughter Ivanka and sons Don Jr. and Eric, and were divorced after a 14-year marriage in 1992. The Manhattan socialite was born Ivana Z…