The “Buffy the Vampire Slayer” star’s family announced his death on March 20.

Nicholas Brendon’s cause of death revealed

The "Buffy the Vampire Slayer" star's family announced his death on March 20.

By Mekishana Pierre

Mekishana Pierre

Mekishana Pierre is a news writer at **. She has been working at EW since 2025. Her work has previously appeared on Entertainment Tonight and Popsugar.

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May 5, 2026 8:32 a.m. ET

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Nicholas Brendon attends Wizard World Comic Con Philadelphia 2017. Credit:

Gilbert Carrasquillo/Getty

- The cause of death for Nicholas Brendon has been revealed.

- The "Buffy the Vampire Slayer" star died on March 20 at 54.

- He died of atherosclerotic and hypertensive cardiovascular disease, with acute pneumonia and previous myocardial infarction being contributing factors.

Nicholas Brendon's cause of death has been revealed, nearly two months after his family announced that the *Buffy the Vampire Star* died at 54 years old.

The actor died of atherosclerotic and hypertensive cardiovascular disease, with acute pneumonia and previous myocardial infarction — commonly known as a heart attack — being contributing factors, according to Page Six, citing his autopsy results.

According to the Mayo Clinic, atherosclerosis "when the blood vessels that carry oxygen and nutrients from the heart to the rest of the body become thick and stiff."

Brendon's death was determined to be natural determined to be natural, and the mechanism of his death was 90 percentage blockage of his right coronary artery.

The actor's family previously told fans that Brendon "passed in his sleep of natural causes" in a statement posted to social media on March 20.

Less than a week after his death, Putnam County Coroner Todd Zeiner told PEOPLE in a statement that the actor was discovered by an unnamed friend who was helping care for him. The friend found Brendon "positioned as if asleep." The coroner also said that no foul play was suspected and that the scene where Brendon was found had no evidence to show that his death was anything but natural.

The *Buffy the Vampire Slayer* star faced several health problems throughout his lifetime, including being diagnosed with cauda equina syndrome. Cauda equina syndrome is a condition that occurs when a person experiences nerve dysfunction at the end of their spinal cord, according to the American Association of Neurological Surgeons. It can be caused by injuries, spinal lesions, tumors, birth abnormalities, and spinal anesthesia.

Nicholas Brendon attends the 2012 Chicago Comic and Entertainment Expo.

Barry Brecheisen/WireImage

Brendon gave fans some insight into his health challenges in a 2023 Instagram post where he reflected on undergoing spinal surgery in 2021 after a fall, another spinal surgery later that year, and being taken to a hospital in 2022 due to a cardiac incident.

"After two spinal surgeries and a heart attack, I've had multiple doctor appointments to juggle, and dealing with health insurance and pre-approvals feels nearly as emotionally exhausting and painful as dealing with my actual injuries," the *Criminal Minds* actor added. "You'd think when the doctor says someone needs an urgent MRI and possibly an additional emergency surgery that the insurance company would get back to the doctor with any kind of answer at all. Right???"

Brendon explained that he needed time to rest after his surgery, "or at least as much as I'm capable of resting," he wrote at the time. "So I somehow ended up 'trapped' in Idyllwild-Pine Cove (California) by about 3 feet of snow and nothing but time to swing on the back porch or paint in front of the fireplace."

Brendon's manager, Theresa Fortier, told the *Los Angeles Times* in 2022 that he was diagnosed with a congenital heart defect following an additional cardiac incident.

"After a second cardiac incident two weeks ago, Brendon was diagnosed with a congenital heart defect that is more common in twins," she told the outlet in 2022 (Brendon had a twin brother, Kelly Donovan). "He is currently under the care of a cardiologist and has been focusing on painting and reducing stress."

Fortier added that Brendon's second 2021 spinal surgery resulted in cerebrospinal fluid leak that caused tachycardia at the time of his second cardiac event.

She said the actor also had a C5/C6 spinal fusion surgery in April 2025.

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Brendon's family alluded to the actor's previous health problems in their death announcement posted to social media.

"While it's no secret that Nicholas had struggles in the past," the family statement said, "he was on medications and treatment to manage his diagnosis and he was optimistic about the future at the time of his passing. Our family asks for privacy during this time as we grieve his loss and celebrate the life of a man who lived with intensity, imagination, and heart. Thank you to everyone who has shown love and support."

Nicholas Brendon as Xander Harris on 'Buffy the Vampire Slayer'.

20th Century Fox Film Corp./Courtesy Everett Collection

In the wake of Brendon's death, his *Buffy *costars, including Sarah Michelle Gellar and Alyson Hannigan, paid tribute to his memory with heartfelt messages on social media.

Charisma Carpenter, who played Cordelia Chase on the series and its spinoff, *Angel**, *shared several behind-the-scenes photos of Brendon of the iconic, supernatural teen drama, writing, "I will miss the version of the man I once knew - someone who was so warm and loving. He was cuddly, funny, silly, self-deprecating, and supremely talented. I loved every scene we had together back in the day. He always kept me on my toes, never delivering a line the same way twice, forcing me to become a better actor by listening."

"I will always remember him in my mind’s eye, in his trailer with the door wide open, in his rocking chair, smoking a cigarette and listening to music. From his trailer, which my window faced on the lot, I could hear all the bands that exemplify the 90s but are also, for me, tied up in the memory of Nicky," she added. "I miss those days and cling to those memories of him today. I offer my condolences to his family, his closest friends - who were with him to the end - and to the fans around the world who found comfort in his work. May he be at peace now."

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