Dong N, et al. - Given severe aortic regurgitation (AR) treatment in patients with decreased left ventricular function and extreme left ventricular dilatation affords a therapeutic dilemma, researchers evaluated risk factors of aortic valve replacement (AVR) for these specific population depending on its performances. This study included retrospectively selected severe AR patients (n = 212) accompanied by LVEF < 50% and LVEDD ≥ 70 mm who had isolated AVR between January 2007 and December 2016. In-hospital mortality rate was estimated to be 7%, and survival rates at 5 and 10 years were estimated to be 88% ± 4% and 73% ± 10%, respectively. A link of in-hospital mortality with preoperative age and LVEF was revealed in logistic regression analysis. The best cut-off value for predicting in-hospital mortality was identified to be LVEF = 35% in ROC analysis. In Kaplan–Meier analysis, lower survival rates were shown in patients with markedly decreased LV function (LVEF < 35%) vs other patients with moderate LV dysfunction (LVEF 36% to 50%). Overall, the observed poor postoperative early- as well as long-term results indicate that AVR may be unsafe for severe AR patients having markedly decreased LV function (LVEF < 35%) and extreme left ventricular dilatation (LVEDD > 70mm).