Amarnath Annapureddy, MBBS, assistant professor in the UNMC Division of Cardiovascular Medicine, said stents, open heart surgery and other interventions have improved the lives of many patients with cardiovascular disease. However, his work focuses on an area of heart disease that is not visible.
“About one-third of patients who come in with chest pain and all the hallmarks of heart blockages don’t actually have any obstructive disease,” Dr. Annapureddy said. “It’s frustrating both for the physician and the patient because they don’t have a concrete diagnosis. They are largely ignored.”
This often–undiagnosed condition, angina with nonobstructive coronary arteries (ANOCA), challenges traditional definitions of heart disease. He describes the diagnosis and management of ANOCA as “seeing the invisible” and says it requires persistence and a willingness to look beyond what standard diagnostic imaging can reveal.
During his fellowship at Yale University, Dr. Annapureddy was mentored by Samit Shah, MD, PhD, who introduced him to the emerging science of microvascular and vasospastic disorders.
“He taught me to think differently,” Dr. Annapureddy said. “Some patients have perfectly normal-looking arteries, but their vessels can suddenly spasm leading to the blood supply to the heart being temporarily cut off. When that happens, the patient feels like they’re having a heart attack but, by the time we test them, everything looks normal again.”
That makes it hard to diagnose these patients, who are often women between the ages of 30 and 60, he said, since the test results are normal.
“They are frequently dismissed or misdiagnosed,” Dr. Annapureddy said. “Many endure years of uncertainty and repeated testing, searching for answers that conventional diagnostics cannot provide.”
He also noted that some of the patients are high-functioning individuals who suddenly can’t perform their normal, everyday activities because of their confusing symptoms.
“They’re told, ‘it’s not your heart,’ but they know something is wrong,” Dr. Annapureddy said. “That uncertainty can be devastating.”
Determined to change that, Dr. Annapureddy joined UNMC in 2024 with a vision to expand diagnostic capabilities and research in this overlooked area. Just months later, UNMC became the first health system in Nebraska to acquire the Abbott Coroventis CoroFlow System, an advanced platform that measures coronary microvascular function in real time.
“UNMC and our division are pioneering in this space,” Dr. Annapureddy said. “We’re performing state-of-the-art diagnostics while keeping the patient’s best interests at heart. If no one else is providing these patients with answers, we should be the ones who do.”
For Dr. Annapureddy, the reward comes when patients receive clarity after years of uncertainty.
“It takes time and meticulous attention,” he said. “But the goal is to help them regain control over their lives.”
Beyond his clinical work, he is also actively involved in research to improve ischemic heart disease evaluation and to advance understanding of ANOCA.
“I take the research very seriously,” said Dr. Annapureddy, the 2025 recipient of the UNMC Department of Internal Medicine’s Scientist Development Award, which supports promising junior faculty early in their career. “My goal is to bring together clinical care and research so we’re not just treating patients but also generating data that will change the field.”
UNMC is known for pushing the boundaries of cardiovascular innovation, he said, and he wants to continue in that direction.
“I want to contribute to the knowledge that shapes the future of cardiovascular care,” he said. “True progress often begins where the eye can’t see – by looking deeper, asking harder questions and refusing to overlook those who have long gone unseen.”