The Putnam County Coroner's Office has released the cause of death for Nicholas Brendon. On May 5th, Coroner Todd Zeiner announced in a report obtained by PEOPLE that Brendon's death was natural and he died of atherosclerotic and hypertensive cardiovascular disease. The report lists acute pneumonia and a previous myocardial infarction as contributing factors. The "mechanism of death" was a 90% blockage in the right coronary artery.
In the report, Zeiner stated that law enforcement present at the scene "found no obvious signs of foul play and assisted me with cataloging the scene. Nothing seemed out of place or disturbed." Zeiner said that a longtime friend of Brendon's, Theresa Fortier, was at his residence and called 911. "Theresa stated the decedent had been having a persistent cough and had been self-medicating with over-the-counter medications. He had been complaining about chest pain. She recommended a hospital, but he declined," Zeiner wrote. "He was a longtime smoker and was apprehensive about going due to his recent back surgery. She advised that he had a recent heart attack several years ago, but he declined any further treatment at that time."
After finding no further evidence at the scene, his body was transported to the coroner for an autopsy, which determined that the actor had a "markedly enlarged heart, severe stenosis of the right coronary artery, moderate stenosis of the left anterior descending and left circumflex arteries, acute pneumonia, and inflammation of the small bowel. The small bowel inflammation is most likely secondary to ischemic changes related to cardiogenic shock."
According to the American Heart Association, atherosclerotic cardiovascular disease is a buildup of plaque in the artery walls and is one of the leading causes of death globally. In videos that Brendon filmed from his home's back deck prior to his death, the coroner noted that he was "markedly coughing" and had a "raspy voice." The clips "provided a basis for his declining health," Zeiner said.
The Buffy the Vampire Slayer alum's death was announced in a statement shared on his official Instagram page on Friday, March 20th. He was 54 years old. "We are heartbroken to share the passing of our brother and son, Nicholas Brendon. He passed in his sleep of natural causes," his family said.
His family added that while many knew him for the roles he brought to life over the years, Brendon had more recently discovered his passion for painting and art. "Those who truly knew him understood that his art was one of the purest reflections of who he was," they said. "While it's no secret that Nicholas had struggles in the past, he was on medications and treatment to manage his diagnosis and he was optimistic about the future at the time of his passing."
Years before his death, Brendon was hospitalized after a "cardiac incident" in August 2022. At the time, the news was also shared on his Instagram account in a since-deleted post apologizing for the actor not "going live as much lately." "Nicky is doing fine now but he had to be rushed to emergency about two weeks ago because of a cardiac incident (tachycardia/arrhythmia). Some of you might remember he had a similar incident after his second spinal surgery last year (for Cauda Equina) but this time," the post continued.
One year prior, in August 2021, a rep for the actor said that Brendon experienced "deep-seated medical problems and immense pain" around the time he was charged with felony prescription fraud.
Brendon rose to fame playing Xander Harris on Buffy the Vampire Slayer alongside costars Sarah Michelle Gellar, Alyson Hannigan, Charisma Carpenter, and David Boreanaz. The television series aired from 1997 to 2003. He also appeared in movies like Unholy and Coherence.
In the months leading up to his death, the Kitchen Confidential actor was involved in ongoing legal disputes, such as a December 2025 lawsuit for over $120,000, alleging unfinished work on renovations on his home. On March 12th, just eight days before he died, Brendon was accused in a court hearing of mistreating workers and putting an AirTag on a contractor, PEOPLE previously reported.
