The cause of death of actor Patrick Muldoon, who passed away at the age of 57, has been officially determined as a heart attack, with multiple contributing factors. According to a report by US Weekly on Wednesday, which reviewed the death certificate issued by the County of Los Angeles' Department of Public Health, Muldoon succumbed to a myocardial infarction.
Medical records indicate that Muldoon also suffered from a hereditary coagulopathy disorder, as well as a pulmonary embolism—a blood clot capable of obstructing vital arteries or the lungs. The actor, widely recognized for his roles on Days of Our Lives and Melrose Place, was cremated on Tuesday, officials confirmed.
Muldoon experienced a heart attack on April 19 at the Beverly Hills residence he shared with his girlfriend, Miriam Rothbart. His manager verified the incident to Variety. According to Muldoon's sister, Shana Muldoon-Zappa, who spoke with TMZ, the actor had gone to take a shower and was discovered unconscious on the bathroom floor when Rothbart checked on him. Paramedics attempted to resuscitate him at the scene.
Muldoon launched his acting career while still a student at the University of Southern California, securing a two-episode arc on the sitcom Who's the Boss? Shortly after graduating in 1991, he landed a recurring three-episode role on the popular teen comedy Saved By The Bell. His breakthrough came when he was cast as boxer Austin Reed on Days of Our Lives, a role he played from 1992 to 1995 and later reprised from 2011 to 2012.
He is also well-known for portraying the villain Richard Hart on Melrose Place during seasons three through five, and for his film role as Zander Barcalow in the 1997 sci-fi movie Starship Troopers, alongside his ex-girlfriend Denise Richards. Muldoon and Richards, who dated on and off for five years in the 1990s, remained close friends. They reunited for his latest acting project, a crime thriller titled Dirty Hands, set for release this year.
Muldoon also made appearances on The Real Housewives of Beverly Hills when Richards was a cast member, and on her reality show Denise Richards & Her Wild Things to film a music video. His dating history includes relationships with Lisa Rinna, Tori Spelling, and Juliette Binoche.
Beyond acting, Muldoon pursued his passion for music as the lead singer and guitarist for the rock band The Sleeping Masses. He also worked as a producer, earning executive producer credits on films such as The Tribes of Palos Verdes, Arkansas, Marlowe, The Dreadful, and most recently Kockroach, currently filming and starring Chris Hemsworth and Taron Egerton.
In his final Instagram post, one day before his death, he expressed excitement about being part of Kockroach, directed by Matt Ross and starring Hemsworth, Egerton, Zazie Beetz, and Alec Baldwin. Fans flooded the post with tributes, with one writing: "Grew up watching you in Starship Troopers. RIP legend."
Muldoon made his last public appearance at the 2026 Saturn Awards in March, posing for photos alongside Richards. Last year, he teased a possible return to Days of Our Lives in a video shared on Peacock's official Instagram page, where he wandered the set and said: "Oh my God I'm in Salem! It's good to be back."
He is survived by his partner Miriam Rothbart, his parents Deanna and Patrick Muldoon Sr., his sister Shana, brother-in-law Ahmet Zappa, and their children Halo and Arrow Zappa.
Tributes from co-stars poured in. Alison Sweeney, who starred with Muldoon on Days of Our Lives, wrote on X: "This is such heartbreaking news. Pat was a rare kind of person – brilliantly talented, endlessly kind and generous in spirit. I was so lucky to have worked with him when I first started at Days, he made me feel at ease right away. He brought his unique charm and humor to work every day. A truly gifted guy, and one who will be profoundly missed."
His Starship Troopers co-star Dina Meyer wrote: "I can't believe he's gone. Pat was one of the kindest people I've ever known and was like a brother to me. He was such a light... always making us laugh. My sincere condolences to his family, and everyone who loved him. He will be missed."
