Impact of Energy Loss Coefficient on Left Ventricular Mass Regression in Patients Undergoing Aortic Valve Replacement: Preliminary Observation

Early hemodynamic performance of the trifecta bioprosthetic valve in patients with aortic valve disease

BACKGROUND

The Trifecta valve (St Jude Medical) is a novel supra-annular aortic bioprosthesis designed to improve hemodynamic performance. We hypothesized that the Trifecta may offer better hemodynamic performance in Japanese patients, in whom the annulus is smaller, compared with Western populations. We compared the early results of hemodynamic performance between the Trifecta and the Magna (Edwards Lifescience) valves at our institution.

METHODS AND RESULTS

The Trifecta was implanted in 33 patients and the Magna was implanted in 41 patients who had aortic valve disease. Postoperative echocardiography was performed just before discharge, and the mean pressure gradient (MPG), effective orifice area (EOA) index and energy loss coefficient (ELCo) index were compared between the 2 groups. The average prosthesis size was similar between the 2 groups (21.1 vs. 21.3mm). The Trifecta group had a significantly lower MPG (P=0.001) and larger EOA index and ELCo index than the Magna group (P<0.001 for both). On multivariate linear regression analysis, use of the Trifecta was the strongest independent determinant of postoperative MPG, EOA and ELCo index.

CONCLUSIONS

The Trifecta valve provides excellent early postoperative hemodynamic performance in Japanese patients. Patients with a small annulus size relative to body size may benefit more from the Trifecta in terms of postoperative hemodynamic performance.

Impact of energy loss index on left ventricular mass regression after aortic valve replacement

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 cm²/m² predicted smaller (<−30.0 %) LVM regression rates (area under the curve = 0.825; P = 0.030). Patients with ELI <1.12 cm²/m² had significantly lower cardiac event-free survival.

Conclusion

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.