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: RWTPW = 2 × PWth/LVDd; RWTIVS + PW = (IVSth + PWth) /LVDd; and RWTIVS = 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-RWTPW 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-RWTIVS + PW was not associated with poor survival on survival analysis or the unadjusted Cox model. Only the adjusted Cox model showed that High-RWTIVS + 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-RWTIVS did not have significant prognostic value. Conclusions When calculating RWT, RWTPW should be recommended for evaluating the mortality risk in ADHF.