Comparing Effects of Tafamidis in Controlling Left Ventricular and Left Atrial Strains in Patients With Wild-Type Transthyretin Amyloid Cardiomyopathy

Background: Although tafamidis is used to treat patients with transthyretin amyloid cardiomyopathy (ATTR-CM), its specific effects on cardiac function remain unclear. Thus, this study aimed to investigate the effect of tafamidis on left atrial (LA) and left ventricular (LV) functions using speckle-tracking echocardiography after 1.5 years of treatment in patients with wild-type transthyretin amyloid cardiomyopathy (ATTRwt-CM). Methods and Results: We included 27 patients (mean age, 76 years) with ATTRwt-CM confirmed by biopsy. We analyzed LV and LA strains using 2-dimensional speckle-tracking echocardiography and compared these parameters before and after a 1.5-year follow up between 20 patients with and 7 patients without tafamidis treatment. Echocardiography speckle tracking examination showed no significant changes in global longitudinal strain (GLS) or LA reservoir strain (LASr) in patients with ATTRwt-CM after 1.5 years of tafamidis treatment. However, significant deterioration of GLS (-9.3 [-11, -7.4] to -8.0 [-9, -6.7]; P=0.0381) and LASr (11 [6, 16] to 6 [5, 11]; P=0.0074) were observed in patients with ATTRwt-CM without tafamidis. Conclusions: The LA and LV functions of patients with ATTRwt-CM treated with tafamidis were more favorable than those of untreated patients.