Left atrial remodelling and reverse remodelling with therapy in new-presentation idiopathic dilated cardiomyopathy

Background: There is an established association between adverse left a trial (LA) remodelling and heart failure, however such evidence focuses on an advanced heart failure population. The aim of this study was to explore the relationship between LA structure, function and therapeutic response following optimal heart failure therapy in patients with newly diagnosed idiopathic dilated cardiomyopathy (DCM). Methods: Sixty-eight patients were studied a median of 13 days following a first presentation for DCM, and compared with 19 healthy controls. Participants underwent transthoracic echocardiography and cardiopulmonary exercise testing at baseline and a median five months later whilst receiving optimal heart failure therapy. LA strain was evaluated by speckle-tracking. Results: Median patient symptom duration prior to enrolment was nine weeks (interquartile range 2-26 weeks). Significant baseline adverse LA remodelling (LA volume index, LAVI 48±14mL/m2 vs. 35±11mL/m2, p < 0.001) and impairment in LA function (LA strain 13±6%vs. 26±7%, p < 0.001) was observed amongst DCM patients compared with controls. Following five months' heart failure therapy DCM patients exhibited reverse LA remodelling (LAVI reduced from 48±14mL/m2 to 35±11mL/m2, p < 0.001) and improvement in LA function (LA strain increased from 13±6% to 19±7%, p < 0.001). There was a significant association between LV and LA function and improved LV function was linearly related to LAVI. Despite significant improvement in VO2PEAK and 6-minute walk distance, no association between LA remodelling or function, and these indices was observed. Conclusions: DCM patients display marked adverse LA remodelling and impairment in LA function early in the disease course. These changes show capacity for significant reversal following appropriate medical therapy.