Cardiomyopathy is a disease that affects the heart muscles and can potentially lead to heart failure. Cardiomyopathy can be acquired or hereditary and makes it hard for the heart to deliver blood to the body. In the United States alone there are over 200,000 cases per year. Risk factors can include weight, blood pressure, family history, illicit drug use, and other diseases such as diabetes. While you cannot prevent cardiomyopathy in many cases, you can reduce your chance by living a healthy lifestyle consisting of a healthy diet, regular exercises and sleep, and controlling blood pressure or high cholesterol.
There are different types of cardiomyopathy, one of which is typically fatal and called transthyretin amyloid cardiomyopathy (ATTR-CM), once diagnosed patients live an average of three to five years. ATTR-CM destabilizes transthyretin proteins leading to amyloid deposition in the heart, leading to heart and cardiac symptoms. Transthyretin proteins are transport proteins that circulate in the blood; when it becomes unstable and unfolds in ATTR-CM, it can build up in the heart as amyloid fibrils which cause the heart to become stiff.
The disease is most common in men over the age of 60 and can be caused by heritable genetic mutations or changes in the regulation of transthyretin due to age. "ATTR-CM is considered to be a rare disease, but it is underdiagnosed," says Dr. Mathew S. Maurer, the trial’s co-chair and a heart failure specialist at Columbia University Vagelos Colle of Physicians and Surgeons and NewYork-Presbyterian. "Until recently, cardiologists rarely tested for ATTR-CM, because diagnosis required a heart muscle biopsy and there has been no treatment for the disease. But now that we can detect the disease with noninvasive imaging, we're finding more cases."
A recent study published in the New England Journal of Medicine from researchers at Columbia University details a 2 ½ year phase three clinical trial of a drug, tafamidis, that significantly reduces deaths and hospitalization in patients with ATTR-CM. Compared to a placebo tafamidis reduced deaths by 30%, reduced cardiovascular-related hospitalizations by 32%, and slowed decline in quality of life among 441 patients enrolled. Tafamidis works by stabilizing transthyretin by preventing its dissociation and ability to form amyloid, thereby preventing any build up as amyloid fibrils. The drug also slows decline in heart function and quality of life without causing additional adverse effects. However, tafamidis is most effective when given earlier in disease progression rather than later. For most ATTR-CM cases patients are diagnosed with advanced disease, leading to less benefit from tafamidis. Diagnosing patients earlier is key to getting the most significant benefit from the drug.
Currently, the U.S. Food and Drug Administration is considering approval of tafamidis from the treatment of ATTR-CM, but Pfizer has established an early access program at specific sites. "Based on this study, tafamidis may offer the first treatment for patients with this type of heart disease," Maurer says. "Right now, the best we can do is manage the symptoms of ATTR-CM."
To learn more about cardiomyopathy watch the video below!
Sources: New England Journal of Medicine, Mayo Clinic, Pfizer
