New Treatments Are Changing Lives for People With This Heart Disease

A few years ago, corporate real estate executive Larry Teel was looking forward to swapping weekly business travel for leisurely trips with his wife. But as Teel approached retirement in 2024, he could barely walk from a ticket counter to a plane without stopping to catch his breath.

A doctor diagnosed Teel, 74, of Newport Beach, California, with a heart condition called transthyretin amyloid cardiomyopathy. He was told he had just two years to live.

"Before I got sick, I would be up at 5 a.m. and down at 11 p.m.," Teel said. "I was always active. But at that point I had no energy, no concentration, and just felt terrible."

His symptoms were the result of a protein, transthyretin, misfolding and forming threadlike structures called amyloid fibrils. In people with transthyretin amyloid cardiomyopathy, a form of a condition called amyloidosis, the fibrils accumulate in the heart and cause it to become stiff and lose its ability to pump. Blood backs up into the lungs and causes shortness of breath, swelling in the legs, and congestion of the liver and kidneys.

As the disease progresses, it can lead to heart failure.

Teel's cardiologist referred him to Lily Stern, MD, an advanced heart disease cardiologist in the Smidt Heart Institute at Cedars-Sinai. Stern confirmed Teel's diagnosis with noninvasive tests and started him on a recently approved therapy.

Stern offered a more optimistic outlook: Teel's condition was treatable.

Why Earlier Diagnosis Matters More Now

"Within the last 10 years, there's been an explosion of novel therapeutics for this condition, and that means fewer people progressing to heart failure," said Stern, associate director of the Cardiac Amyloid Program in the Smidt Heart Institute. "These treatments work best when patients are diagnosed early, before showing significant signs of heart failure. Larry came to Cedars-Sinai at just the right moment."

Transthyretin amyloid cardiomyopathy is considered rare, but experts believe it is severely underdiagnosed.

Symptoms of the disease may develop slowly, and doctors may attribute them to other conditions rather than the underlying disease. Teel, for example, had been diagnosed with atrial fibrillation, an irregular heart rhythm, which his doctors now understand was related to the accumulation of amyloid fibrils in his heart.

There are two main types of transthyretin amyloid cardiomyopathy, also called ATTR-CM. One, a hereditary type, is caused by a mutation in a gene called TTR. The other-the type that Teel has-is wild-type transthyretin amyloid cardiomyopathy, where the gene is normal, but the transthyretin protein still misfolds.

New Treatments Are Changing Amyloid Cardiomyopathy Care

It used to be that people with transthyretin amyloid cardiomyopathy had no treatment options and lived with their condition getting worse every year. For those with advanced disease, only a few were eligible for a heart transplant. A pivotal moment came in 2019 when the U.S. Food and Drug Administration (FDA) approved the first medication specifically indicated for transthyretin cardiac cardiomyopathy. The drug, tafamidis, works by preventing transthyretin from breaking apart and misfolding into amyloid.

Stern and research colleagues from the U.S. and abroad were part of clinical trials that led to approval in 2024 of another transthyretin stabilizer, acoramidis. Stern's team enrolled patients from Cedars-Sinai in the Phase III clinical trial of that drug, which found that people who took acoramidis had fewer hospitalizations and other complications over 30 months than patients given placebo.

Most recently, in 2025, the FDA approved vutrisiran, a drug that limits the production of transthyretin. More drugs are being studied and developed, including ones that permanently edit out the TTR gene. Scientists are also studying treatments that clear amyloid from the heart.

Answering the Next Questions About Amyloid Cardiomyopathy

Stern helped create a registry that includes more than 2,800 patients from 28 medical centers across North America who have been diagnosed with different types of amyloid cardiomyopathy. Researchers plan to use the data to improve knowledge of how amyloid cardiomyopathy progresses and is affected by treatments.

The ongoing investigations have the potential to not only help people like Teel, but also those who develop other heart conditions, Cedars-Sinai experts say.

"Knowing we can now offer patients like Larry meaningful treatment outcomes for a complex heart condition is further motivation to accelerate scientific findings that can be applied to multiple diseases," said Susan Cheng, MD, MPH, chair of the Department of Cardiology in the Smidt Heart Institute.

Although scientists have made major advances in diagnosing and treating this disease, more research is needed, according to Michelle Kittleson, MD, PhD, professor of Cardiology in the Smidt Heart Institute. "There remain many unanswered questions regarding response to therapy and adjustment of therapy in response to disease progression," she said.

Teel is grateful for the medical research and care that has given him more time with his wife, six children and five grandchildren.

"About two months after treatment, suddenly I could think," he said. "About three months later, I could walk. More than a year later, I feel like I'm alive again."

Read more from the Cedars-Sinai Newsroom: WebMD | Navigating hATTR-CM-Why Self-Advocacy Matters