A new study has found that some patients with wild-type transthyretin amyloid cardiomyopathy (ATTRwt-CM), a companion subtype to hereditary transthyretin amyloidosis (hATTR) with cardiomyopathy (ATTR-CM), have preserved endothelial function.
The study, published in the Journal of Clinical Medicine, speculates that these patients might have elevated brain natriuretic peptide (BNP) levels, thereby compensating endothelial function.
“There is no information on vascular function in patients with ATTR-CM,” the authors wrote. “We measured flow-mediated vasodilation as an index of endothelial function and nitroglycerine-induced vasodilation as an index of vascular smooth muscle function by using a high-resolution ultrasound system and we measured brachial artery intima-media thickness and brachial-ankle pulse wave velocity as indices of arterial stiffness in patients with ATTRwt-CM.”
The research team assessed vascular function in 3792 patients without ATTRwt-CM and 22 patients with ATTRwt-CM from a single center in Japan. An endomyocardial biopsy was performed on all patients with ATTRwt-CM; various blood and vascular function tests were also conducted. Echocardiograms were obtained from all patients.
Read more about hATTR complications
The results showed that flow-mediated vasodilation was significantly greater in patients with ATTRwt-CM than in controls, and there was also a significant correlation between BNP levels, ventricular wall thickness, and flow-mediated vasodilation in this group. Furthermore, endothelial function was preserved and increased in patients with ATTRwt-CM.
The authors speculate that a compensatory function based on elevated BNP levels may underlie the preserved endothelial function in patients with ATTRwt-CM. However, 2 of the 3 patients with advanced heart failure and ATTRwt-CM died during the study period, suggesting that in cases of advanced heart failure, elevated BNP levels cannot compensate for endothelial dysfunction.
The research team concluded that although the prognosis is poor for patients with ATTRwt-CM, those without advanced heart failure may have preserved endothelial function. They recommend early diagnosis and treatment of these patients.
Reference
Hashimoto Y, Yamaji T, Kitagawa T, et al. Endothelial function is preserved in patients with wild-type transthyretin amyloid cardiomyopathy. J Clin Med. 2023;12(7):2534. doi:10.3390/jcm12072534
