Whitney Houston appears to have used cocaine "in the time period just immediately prior to her collapse in the bathtub at the hotel," said L.A. County Chief Coroner Craig Harvey.
Houston,48, was determined to have accidentally drowned Feb. 11 following an apparent heart episode with cocaine as contributing factor. A 60% narrowing of Houston's arteries "suggest a cardiac event complicated by the cocaine use" that led to Houston slipping underwater, Harvey said.
"Something happened that caused her to go down and we know that when she slipped under the water she was still alive," he said.
Officials would not say how much of the drug was in her system. But Harvey, the coroner's operations chief, said the toxicology findings "suggested chronic usage" of the drug.
David Campbell, a retired captain for the coroner's office, said a heart condition is often linked to blockages of blood flow to the heart. Use of cocaine and other narcotics would intensify the dangers, he said.
Cocaine can constrict blood vessels and reduce blood flow, he said.
The autopsy results were released Thursday after weeks of intense speculation over how the 48-year-old pop star died.
Houston had battled drug addiction for years, and the coroner's office found traces of several drugs — including marijuana, the anti-anxiety medication Xanax, the muscle relaxant Flexeril, as well as Benadryl — in her system.
But the coroner's office concluded that those drugs did not contribute to her death. A law enforcement source said no cocaine was found in Houston's room at the Beverly Hilton Hotel but that bottles of various medications were recovered.
The autopsy found the singer suffered from a pre-existing condition known as atherosclerotic heart disease. Beverly Hills police said detectives will prepare a final report, due to be released in two weeks, after they review the coroner's findings.
Investigators had served subpoenas on doctors, as well as at the pharmacies where Houston obtained the prescriptions they found in her hotel room. But officials said they don't believe any of the prescribed medications played a role in her death.
Authorities did not say how long those drugs had been in her system.
Houston was found submerged in the bathtub of her hotel room the afternoon by an assistant. Beverly Hills Fire Department paramedics performed CPR on the singer for about 20 minutes before pronouncing her dead.
