THURSDAY, June 8, 2023 (HealthDay News) -- Patients who develop a devastating heart condition have new reason to hope after a study identified three men whose condition spontaneously reversed.
The condition is called transthyretin cardiac amyloidosis. It involves a buildup of sticky, toxic proteins that can lead to heart failure. About half of patients die from the progressive disease within four years of diagnosis.
Until now, it was believed to be irreversible.
Yet these three men, aged 68, 76 and 82, recovered. Not only did their symptoms improve, but cardiovascular magnetic resonance (CMR) scans showed that the buildup of amyloid proteins in the heart had cleared, according to a new report.
“We have seen for the first time that the heart can get better with this disease," said lead study author Marianna Fontana, a professor in the division of medicine at University College London, in the United Kingdom.
"That has not been known until now and it raises the bar for what might be possible with new treatments,” Fontana added in a university news release.
The men had evidence of an immune response that specifically targeted amyloid. These amyloid-targeting antibodies were not found in other patients whose condition progressed as normal.
“Whether these antibodies caused the patients’ recovery is not conclusively proven,” said study co-author Julian Gillmore. "However, our data indicates that this is highly likely and there is potential for such antibodies to be recreated in a lab and used as a therapy. We are currently investigating this further, although this research remains at a preliminary stage." Gillmore is head of the UCL Centre for Amyloidosis, based at the Royal Free Hospital.
Transthyretin amyloidosis (ATTR) is caused by amyloid deposits composed of a blood protein called transthyretin (TTR). This can be both hereditary and non-hereditary. Doctors call the buildup of these protein deposits in the heart ATTR amyloid cardiomyopathy (ATTR-CM).
This study was launched after one of men reported his symptoms improving. After that, researchers looked through the records of more than 1,663 patients diagnosed with the condition, finding two others whose condition reversed.
The recoveries were confirmed with blood tests and imaging techniques. One patient also had an assessment of exercise capacity. CMR scans showed heart structure and function had returned to a near-normal state and amyloid had almost completely cleared.
This did not happen in the other patients studied.
In one case, a heart muscle biopsy revealed an atypical inflammatory response surrounding the amyloid deposits, including white blood cells known as macrophages, that suggested an immune reaction. Among 286 other biopsies, none had this evidence. Those were all from patients whose disease followed a normal progression.
The researchers found antibodies in the three patients that bound specifically to ATTR amyloid deposits in mouse and human tissue and to synthetic ATTR amyloid. These were not found in 350 other patients in the cohort.
The team believes that if these antibodies could be harnessed, they could be combined with new therapies that suppress TTR protein production. This would make it possible to clear away amyloid and to prevent further deposits.
Current treatments are those that work to relieve heart failure symptoms, but don’t target amyloid.
The report was published June 7 as a letter in the New England Journal of Medicine.
More information
The American Heart Association has more on ATTR-CM.
SOURCE: University College London, news release, June 7, 2023
