Background: In patients with severe aortic stenosis or decompensated heart failure with preserved ejection fraction (HFpEF), beta-blockers are usually discontinued despite the absence of unequivocal evidence. The data on the effect of beta-blockers in patients with moderate aortic stenosis (MAS) are scarce. Aim: To investigate the relationship between beta-blocker use and outcome in patients with MAS, who were hospitalized for decompensated HFpEF. Methods: The current study includes 61 patients admitted for decompensated HFpEF with concomitant MAS. The mean age of the population was 82.7±7.59 years old and 41% were females. The diagnosis MAS was established on criteria including aortic valve area between 1-1.5 cm², mean gradient - 20-39 mmHg, and max velocity between 3-3.9 m/s. For those with borderline measurements, the Doppler Velocity Index (DVI) was calculated (DVI < 0.25 indicates severe aortic stenosis). All echocardiographic data were assessed by an experienced echocardiographer. Patients with previous aortic valve replacement and a severe mixed of multivalvular disease were excluded. Result: The median follow-up was 52 months (interquartile range 34-63 months). During this period 38 patients (62.3%) died from any cause while 42 (68.9%) individuals experienced a composite endpoint, of all-cause death or hospitalization due to worsening HFpEF. In survivors, we observed higher prescription of beta-blockers at hospital discharge (66% vs. 34%, p<0,05) and better diastolic function than in patients with endpoints. In multivariate Cox regression analysis the use of beta-blockers (HR = 0,27; 95% CI 0,13-0,57; p<0.01) and better diastolic function, defined as higher septal e` (HR=0,76; 95% CI 0,61-0,94; p=0.01) were identified as independent predictors for both - survival and composite endpoint (Figure 1). Advanced age was recognized as an associated factor for outcomes. Conclusion: In the present study, continuation of beta-blockers at discharge was independently associated with better survival in patients with decompensated HFpEF and concomitant MAS. It remains to be addressed in future studies, whether or not beta-blockers should be started in these patients or if there is any prognostic interaction between beta-blockers and aortic valve intervention for MAS.Figure 1.Kaplan-Meier survival curve