Limited utility of the subcostal view for the echocardiographic evaluation of left ventricular mass in epidemiological studies of older persons

Background: Epidemiological estimates of left ventricular mass are based on echocardiographic imaging from the parasternal view, which is often unavailable in subjects with obesity or lung disease. This study was undertaken to assess whether the subcostal view is a valid alternative to estimate left ventricular mass in an unselected older population. Methods: In a cross-sectional study of all the residents in Dicomano, Italy, aged ≥65 years, echocardiography was performed with a systematic attempt to obtain both the parastermal and the subcostal views. Results: The parasternal view was missing in 73/614 participants, 48 of whom were imaged from the subcostal view. In participants imaged from both views, the subcostal view underestimated left ventricular cavity dimension and, consequently, left ventricular mass [79.7 (1.3) vs. 93.3 (1.5) g/m2; p<0.001]. Furthermore, the subcostal view was only 25% sensitive for the diagnosis of hypertrophy. Several multivariate regression models, developed in an equation development subgroup and tested in a validation subgroup, failed to correct the prediction of left ventricular mass based on measures taken from the subcostal view, also after inclusion of demographic, anthropometric, and spirometric covariates. Conclusions: In unselected older persons, the subcostal view does not improve the accuracy of echocardiographic estimation of left ventricular mass, which remains biased in epidemiological studies.