Columbia researchers have found a link between a common back condition and a type of heart failure, suggesting that screening patients with spinal stenosis could identify those at risk for heart disease and prevent premature death.
Once thought to be rare, heart disease, called transthyretin amyloid cardiomyopathy, is now considered a more common but underdiagnosed cause of heart failure. The disease is caused by proteins called transthyretin which can clump together and create amyloid deposits in the heart, spine, ligaments and other tissues. In the heart, deposits stiffen the walls and reduce the amount of blood the heart can pump.
Until recently, no treatment was available for this type of heart failure. But in 2019, after a clinical trial conducted by the Columbia cardiologist Mathew S. Maurer, MD, the FDA has approved a drug that prevents amyloid transthyretin deposition. (Amyloid deposits also appear in Alzheimer’s disease, but these develop from a different protein and cannot be treated with the drug).
“We have a good treatment that reduces the risk of dying from this disease, and now we clearly need a better way to screen people and find those at risk,” says Maurer, a professor of medicine at Columbia University Vagelos. College of Physicians and Surgeons. “Because the drug does not reduce existing amyloid, it is most effective when taken early in the disease.”
Recent studies suggest that many patients diagnosed with lumbar spinal stenosis develop transthyretin amyloid cardiomyopathy five to 15 years after their diagnosis of stenosis. This led Maurer to wonder if screening patients with stenosis undergoing surgery could identify those at risk for transthyretin cardiomyopathy or who are already in the early stages.
“Many patients with spinal stenosis undergo spine surgery, and it’s easy to take a sample of tissue taken during the procedure and test it for amyloid transthyretin,” says Maurer. If amyloid is present in the spine, doctors may use advanced imaging or a heart muscle biopsy to determine if the heart is also affected.
To see if such screening was worth it, Maurer’s team at Columbia analyzed the spinal tissue of 47 patients (ages 62 to 76) undergoing spinal decompression surgery. The researchers detected amyloid in the spine of 34% of the patients; two-thirds had transthyretin amyloid, while the amyloid content of the other third could not be identified. Of those with confirmed transthyretin amyloid (10 patients), one had previously developed cardiac amyloidosis and subsequently started treatment with tafamidis. The other nine patients are being closely monitored by their doctors for future heart problems.
“Based on these findings, we suggest that all patients undergoing surgery for spinal stenosis be screened for amyloid transthyretin,” Maurer says. “I would definitely recommend screening if a patient has additional orthopedic issues, such as carpal tunnel syndrome, joint deterioration, or biceps tendon injury, each of which may be caused by amyloid transthyretin. These patients are particularly likely to have amyloid transthyretin and be at risk for heart failure in the future.