Left atrial remodeling in heart failure: the role of sphericity index (the SPHERICAT-HF study)

Left atrial sphericity index (LASI) is an echocardiographic index easily obtained; its use in patients with heart failure (HF) has never been investigated so far. This single-centre study aimed to investigate the usefulness of LASI in an unselected cohort of patients hospitalized for acute HF, and its potential correlation with the amino-terminal portion of pro-B-type natriuretic peptide (NT-proBNP) levels and with New York Heart Association (NYHA) functional class. Ninety-four consecutive HF patients underwent a transthoracic echocardiogram with a detailed study of the left atrium (LA) including LASI (calculated from the apical four-chamber view as the ratio between the transverse and longitudinal diameters), and blood tests (including NT-proBNP) on the same day. Median age was 75.5 (interquartile range-IQR 62-82) years and 55% were males, 58.5% had a NYHA class III-IV, and median NT-proBNP was 3284 (IQR 1215-7055) pg/ml. The LA was dilated in 94%, and median biplane LA volume index was 62 ml/m². Patients with advanced NYHA class showed more advanced LA remodeling. Mean LASI was 0.78 ± 0.09 and did not correlate with NT-proBNP levels (r 0.03; p 0.75) or with patient NYHA class (R² 0.011; p 0.287). None of the echocardiographic indices of LA structural and functional remodeling proved to be independently associated with a high NYHA class on multivariate regression analysis. In conclusion, LA remodeling is almost invariably present in patients with HF. LASI does not correlate with NT-proBNP levels or with NYHA functional class. Further studies are needed to describe the complex patterns of atrial remodeling in HF.