Bruce, 24, died on April 28 after what was reported to be a medical episode while driving his vehicle in Fort Lauderdale, Florida.
The Broward County Medical Examiner report confirmed the former wide receiver's death was "natural" and caused by coronary artery disease.
Bruce was reported to have suffered a seizure, leading to a crash on Northwest 22nd Road and taken to the hospital, where he was pronounced dead the following morning.
"At this time, the circumstances surrounding this incident are not suspicious and foul play is not suspected," Fort Lauderdale Police Detective Ali Adamson said at the time of Bruce's death via WPTV.
Bruce emerged as one of the nation's top wide receiver prospects while playing for St. Thomas Aquinas in Fort Lauderdale, rating as a four-star prospect and ranking as the No. 11 wide receiver, No. 13 player from the state of Florida and No. 84 overall prospect for the 2016 national recruiting cycle, according to 247Sports' composite rankings.
Bruce signed with Miami, but was dismissed from the team prior to ever appearing in a game and later had stints with Mississippi Gulf Coast Community College and Southeastern University.
Bruce also made appearances for the Frisco Fighters of the Indoor Football League.