Energy Loss Index as a Predictor of All-Cause Mortality after Transcatheter Aortic Valve Replacement: A 9-year follow-up

Background: As transcatheter aortic valve replacement (TAVR) procedures become more widely available, there is a growing need to monitor and evaluate postoperative outcomes accurately. The energy loss index (ELI) of the ascending aorta has been commonly used to examine the agreement between the echocardiographic and Gorlin measurement of the aortic valve area. Objectives: This project aims to demonstrate a link between ELI values and mortality following implanted TAVR valves and determine an ELI cutoff value associated with post-TAVR events. Method: We retrospectively reviewed patients undergoing TAVR from 2012 – 2017. We calculated ELI values for patients immediately postoperative after a TAVR procedure. Using Receiver-Operator Characteristic and Cox Regression analyses, we identified a cutoff value to distinguish between high and low-risk patients. Results: : This study showed ELI ≤ 1.34 (hazard ratio, 1.783; 95% confidence interval 1.231-2.583, p=0.002) as representative of patients with a high risk of mortality post-TAVR. Additionally, post-TAVR, ejection fraction increased by 3.5 percent (p<0.001), and the aortic valve effective orifice area increased by 1.25 cm squared (p<0.001) while the mean transvalvular gradient decreased by 33.6 mmHg (p<0.001) and the peak transvalvular gradient decreased by 49.7 mmHg (p<0.001). Conclusion: ELI is an additional prognostic factor that should be considered during risk assessment before TAVR. This study shows that patients with ELI ≤ 1.34 had decreased cumulative survival post-TAVR. These patients had a fivefold increased risk of death following TAVR.