Effects of tafamidis on the left ventricular and left atrial strain in patients with wild-type transthyretin cardiac amyloidosis

Although tafamidis is used in patients with wild-type transthyretin cardiac amyloidosis (ATTRwt-CA), its specific effect on cardiac function is unclear. Thus, this study aimed to investigate the effect of tafamidis on left atrial and ventricular function using speckle-tracking echocardiography for 1 year of treatment in patients with ATTRwt-CA.We included 23 patients (mean age, 76 years) with ATTRwt-CA confirmed via biopsy. We analyzed the left ventricular and left atrial (LA) strain using two-dimensional speckled tracking echocardiography and compared these parameters before and 1 year after starting treatment with tafamidis between 16 patients with sinus rhythm (SR) and 7 patients with atrial fibrillation (AF). In ATTRwt-CA patients with SR, LA reservoir strain significantly improved by 1-year tafamidis treatment (10.5±5.0% to 11.9±5.3%, P=0.0307) although global longitudinal strain (GLS) did not (-10.6±3.1% to -11.3±3.0%, P=0.0608). In contrast, LA reservoir strain was not significantly changed (5.4±2.9% to 4.9±1.7%, P=0.4571), and GLS deteriorated (-8.4±2.3% to -6.8±1.4%, P=0.0267) in ATTRwt CA patients with AF.Left atrial function improved with tafamidis treatment in ATTRwt-CA patients with SR, but not left ventricular function. However, these cardiac functions did not improve with tafamidis treatment in ATTRwt-CA patients with AF.