title: Impact of energy loss index on left ventricular mass regression after aortic valve replacement.
abstract: BACKGROUND
  Recently, the energy loss index (ELI) has been proposed as a new functional index to assess the severity of aortic stenosis (AS). The aim of this study was to investigate the impact of the ELI on left ventricular mass (LVM) regression in patients after aortic valve replacement (AVR) with mechanical valves.
  
  
  METHODS
  A total of 30 patients with severe AS who underwent AVR with mechanical valves was studied. Echocardiography was performed to measure the LVM before AVR (pre-LVM) (n = 30) and repeated 12 months later (post-LVM) (n = 19). The ELI was calculated as [effective orifice area (EOA) × aortic cross sectional area]/(aortic cross sectional area - EOA) divided by the body surface area. The LVM regression rate (%) was calculated as 100 × (post-LVM - pre-LVM)/(pre-LVM). A cardiac event was defined as a composite of cardiac death and heart failure requiring hospitalization.
  
  
  RESULTS
  LVM regressed significantly (245.1 ± 84.3 to 173.4 ± 62.6 g, P < 0.01) at 12 months after AVR. The LVM regression rate negatively correlated with the ELI (R = -0.67, P < 0.01). By receiver operating characteristic (ROC) curve analysis, ELI <1.12 cm(2)/m(2) predicted smaller (<-30.0 %) LVM regression rates (area under the curve = 0.825; P = 0.030). Patients with ELI <1.12 cm(2)/m(2) had significantly lower cardiac event-free survival.
  
  
  CONCLUSIONS
  The ELI as well as the EOA index (EOAI) could predict LVM regression after AVR with mechanical valves. Whether the ELI is a stronger predictor of clinical events than EOAI is still unclear, and further large-scale study is necessary to elucidate the clinical impact of the ELI in patients with AVR.
authors: Division of Cardiology, Kawasaki Medical School, 577 Matsushima, Kurashiki, 701-0192 Japan.
authors: Terumasa
authors: T
authors: Koyama
authors: Division of Cardiology, Kawasaki Medical School, 577 Matsushima, Kurashiki, 701-0192 Japan.
authors: Hiroyuki
authors: H
authors: Okura
authors: Division of Cardiology, Kawasaki Medical School, 577 Matsushima, Kurashiki, 701-0192 Japan.
authors: Teruyoshi
authors: T
authors: Kume
authors: Division of Cardiology, Kawasaki Medical School, 577 Matsushima, Kurashiki, 701-0192 Japan.
authors: Kenzo
authors: K
authors: Fukuhara
authors: Division of Cardiology, Kawasaki Medical School, 577 Matsushima, Kurashiki, 701-0192 Japan.
authors: Koichiro
authors: K
authors: Imai
authors: Division of Cardiology, Kawasaki Medical School, 577 Matsushima, Kurashiki, 701-0192 Japan.
authors: Akihiro
authors: A
authors: Hayashida
authors: Division of Cardiology, Kawasaki Medical School, 577 Matsushima, Kurashiki, 701-0192 Japan.
authors: Yoji
authors: Y
authors: Neishi
authors: Division of Cardiology, Kawasaki Medical School, 577 Matsushima, Kurashiki, 701-0192 Japan.
authors: Takahiro
authors: T
authors: Kawamoto
authors: Division of Cardiovascular Surgery, Kawasaki Medical School, Kurashiki, Japan.
authors: Kazuo
authors: K
authors: Tanemoto
authors: Division of Cardiology, Kawasaki Medical School, 577 Matsushima, Kurashiki, 701-0192 Japan.
authors: Kiyoshi
authors: K
authors: Yoshida
keywords: Aortic stenosis; Aortic valve replacement; Energy loss coefficient; Energy loss index; Prosthesis–patient mismatch