Recovery of right ventricular function in patients with transthyretin cardiac amyloidosis after one-year tafamidis administration.

Abstract

Baseline cardiac functions are known to be potent predictors of cardiovascular events in the natural history of transthyretin amyloid cardiomyopathy (ATTR-CM). However, previous studies have not shown functional and morphological changes in the heart during tafamidis administration. This study aimed to evaluate the effect of tafamidis on cardiac function by measuring right ventricular strain in patients with ATTR-CM. We performed a retrospective analysis of serial transthoracic echocardiography examinations (at baseline and one year after tafamidis introduction) using a vendor-independent speckle-tracking analyzer in patients with ATTR-CM. The entire cohort (n = 33; 30 men; mean age, 81 ± 5 years) was divided into two subgroups: the tafamidis treatment (n = 18) and the control (n = 15). After one-year tafamidis administration (oral tafamidis meglumine, 80 mg once daily), the average value of the right ventricular (RV) free wall longitudinal strain (RVFWLS) significantly improved (-17.8 ± 7.9% vs. -24.5 ± 9.1%, p = 0.001), with a significant decrease in the frequency of positive RVFWLS test result (≥-22.0%) in the treatment subgroup (72% vs. 44%, p = 0.033). Moreover, tafamidis administration had large impact on RVFWLS improvement (p = 0.007, odds ratio: 22.0, 95% confidence interval: 2.344-206.480). A significant recovery of RV function was measured using RVFWLS. This may be one of the pathophysiological mechanisms underlying the favorable effects of tafamidis.