Left atrial strain by speckle tracking predicts atrial fibrosis in patients undergoing heart transplantation.

AIMS: In patients with heart failure (HF), chronically raised left ventricular (LV) filling pressures lead to progressive left atrial (LA) dysfunction and fibrosis. We aimed to assess the correlation of LA reservoir strain (peak atrial longitudinal strain, PALS) by speckle tracking echocardiography (STE) and LA fibrosis assessed by myocardial biopsy in patients undergoing heart transplantation (HTx). METHODS AND RESULTS: Forty-eight patients with advanced HF [mean age 51.2 ± 8.1 years, 29% females; LV ejection fraction ≤25% and New York Heart Association (NYHA) class III-IV] referred for HTx were enrolled and underwent pre-operative echocardiographic evaluation, right heart catheterization, and cardiopulmonary exercise testing. Exclusion criteria were non-sinus rhythm, mechanical ventilation, severe mitral/tricuspid regurgitation, or other valvular disease and poor acoustic window. After HTx, LA bioptic samples were collected and analysed to determine the extent of myocardial fibrosis (%). LA fibrosis showed correlation with PALS (R = -0.88, P < 0.0001), VO2max (R = -0.68, P < 0.0001), NYHA class (R = 0.66, P < 0.0001), LA stiffness (R = 0.58, P = 0.0002), and E/e' (R = 0.44, P = 0.005), while poorly correlated with E/A ratio (R = 0.23, P = 0.21). PALS had a good correlation with NYHA class (R = -0.64, P < 0.0001), PAoP (R = -0.61, P = 0.03) and VO2max (R = 0.57, P = 0.0001). Multivariate regression analysis identified PALS (beta = -0.91, P < 0.001) and LA Volume (beta = -0.19, P = 0.03) as predictors of LA Fibrosis, while E/e' was not a significant predictor (beta = 0.15, P = 0.08). CONCLUSION: Emerging as a possible index of myocardial fibrosis in patients with advanced HF, PALS could help to optimize the management and the selection of those patients with irreversible LA structural damage for advanced therapeutic strategies.

The role of the left atrial function in the surgical management of aortic and mitral valve disease.

The right management of both mitral and aortic disease can be challenging, especially in asymptomatic patients. The current guidelines recommend valve repair or replacement when symptoms arise or when there is an evident left ventricular dysfunction. However, deciding the optimal surgical timing can be very difficult, since the line between the absence of symptoms and being minimally symptomatic, especially in the elderly, is blurred. Another relevant issue regards the second surgical criterion: operating on a patient with a reduced left ventricular ejection fraction or with a dilated left ventricle might jeopardize the possibility of a fully reverse remodeling of the heart after surgery. In this scenario, the left atrium might play an important role. In particular, left atrial deformation might be a very useful tool to detect early ultrastructural alterations, and help or support guiding a patient-tailored treatment at an early stage, optimizing the outcome in the long term.

RV Longitudinal Deformation Correlates With Myocardial Fibrosis in Patients With End-Stage Heart Failure.

OBJECTIVES: This study was performed to determine the accuracy of right ventricular (RV) longitudinal strain (LS) in predicting myocardial fibrosis in patients with severe heart failure (HF) undergoing heart transplantation. BACKGROUND: RVLS plays a key role in the evaluation of its systolic performance and clinical outcome in patients with refractory HF. METHODS: We studied 27 patients with severe systolic HF (ejection fraction ≤25% and New York Heart Association functional class III to IV, despite full medical therapy and cardiac resynchronization therapy) using echocardiography before heart transplantation. RV free wall LS, right atrial LS, sphericity index (SI), and tricuspid annular plane systolic excursion (TAPSE) were all measured. Upon removal of the heart, from the myocardial histologic analysis, the ratio of the fibrotic to the total sample area determined the extent of fibrosis (%). RESULTS: RV myocardial fibrosis correlated with RV free wall LS (r = 0.80; p < 0.0001), SI (r = 0.42; p = 0.01) and VO2 max (r = -0.41; p = 0.03), with a poor correlation with TAPSE (r = -0.34; p = 0.05) and right atrial LS (r = -0.37; p = 0.03). Stepwise multivariate analysis showed that RV free wall LS (ß = 0.701, p < 0.0001) was independently associated with RV fibrosis (overall model R(2) = 0.64, p < 0.0001). RV free wall LS was the main determinant of myocardial fibrosis. In the subgroup of patients with severe RV fibrosis, RV free wall LS had the highest diagnostic accuracy for detecting severe myocardial fibrosis (area under the curve = 0.87; 95% confidence interval: 0.80 to 0.94). CONCLUSIONS: In late-stage HF patients, the right ventricle is enlarged, with reduced systolic function due to significant myocardial fibrosis. RV free wall myocardial deformation is the most accurate functional measure that correlates with the extent of RV myocardial fibrosis and functional capacity.