Comparison of the prognostic values of three calculation methods for echocardiographic relative wall thickness in acute decompensated heart failure

PURPOSE: Left ventricular (LV) wall thickness can be measured at the posterior wall (PW) and the intraventricular septum (IVS) in a parasternal long axis view by transthoracic echocardiography. Thus, there are three methods to calculate relative wall thickness as follows: RWT(PW) = 2 × PWth/LVDd; RWT(IVS + PW) = (IVSth + PWth) /LVDd; and RWT(IVS) = 2 × IVSth/LVDd (IVSth = interventricular septum thickness; LVDd = LV internal dimension at end--diastole; PWth = posterior wall thickness). The aim was to compare the prognostic values of these RWTs in patients with acute decompensated heart failure (ADHF). METHOD: This was a single-center, retrospective, observational study at a Japanese community hospital. A total of 389 hospitalized ADHF patients were divided into two groups based on the three median RWT values. The primary outcome was all-cause death. Survival analysis was performed, and Cox proportional hazard models unadjusted and adjusted by Get With The Guideline score were used. RESULTS: High-RWT(PW) had poor survival (log-rank, P = 0.009) and was a significant risk (unadjusted HR (95%CI), 1.72 (1.14–2.61), P = 0.01; adjusted HR, 1.95 (1.28–2.98), P = 0.02). High-RWT(IVS + PW) was not associated with poor survival on survival analysis or the unadjusted Cox model. Only the adjusted Cox model showed that High-RWT(IVS + PW) was associated with a significant risk of the primary outcome (unadjusted HR (95%CI), 1.45 (0.96–2.17), P = 0.07; adjusted HR, 1.53 (1.01–2.32), P = 0.045). High-RWT(IVS) did not have significant prognostic value. CONCLUSIONS: When calculating RWT, RWT(PW) should be recommended for evaluating the mortality risk in ADHF.