Buffy the Vampire Slayer star Nicholas Brendon’s cause of death has been ruled natural due to complications related to cardiovascular disease, according to a report released by the Putnam County Coroner’s office. According to multiple outlets, coroner Todd Zeiner found that Brendon died in March of natural causes from atherosclerotic and hypertensive cardiovascular disease, with acute pneumonia and previous myocardial infarction as contributing factors. Specifically, Brendon had a 90% blockage of the right coronary artery. “Autopsy demonstrated an adult male with 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,” Zeiner wrote.…