Role of reduced left atrial mechanical function reserve in exercise intolerance progression in hypertensive heart disease

Abstract Funding Acknowledgements Type of funding sources: None. Background The identification of mechanisms in hypertensive heart disease (HHD) that favor the development of symptomatic heart failure (HF) is essential. Little is known about the role of left atrial (LA) mechanical response to exertion in this context. Objectives We sought to investigate the association of LA strain parameters response to exercise with functional capacity and symptomatic HF in a representative group with HHD. Methods Echocardiography (including LA strain and strain-derived LA stiffness index assessment) was performed at rest and immediately post exercise test in 61 patients with stage A, 67 patients with stage B and 73 patients with stage C HF. Results There was a progressive worsening of exercise capacity from stage A through stage B to stage C, which was accompanied by a gradual impairment of changes from rest to exercise in LA reservoir and contractile strain, whereas LA stiffness reserve remained unchanged until the HF stage C (Table). In multivariable analysis including LA and left ventricular reserve and clinical variables, changes from rest to exercise in LA reservoir strain and mitral annular e’ (both beta 0.16, SE 0.07, p = 0.02) were the only cardiac function parameters independently correlating with exercise capacity. However, LA stiffness reserve and E/e’ were the strongest associations of symptomatic HF stage C (Akaike information criterion 111.6 and 101.1, respectively). Conclusions LA reservoir strain and LA stiffness exercise reserves are among the mediators of reduced functional capacity in HHD, however the trajectories of changes of these parameters are not parallel. While LA strain reserve progressively deteriorates across HF stages, a marked impairment in LA stiffness reserve can only be seen in patients with HF symptoms. This suggests a potential role for these parameters in stratifying the risk of progression to overt HF in HHD.