Introduction. Risk prediction in acute heart failure (AHF) has led to the development of multiple prognostic models. Emerging data highlight the prognostic significance of right ventricular (RV) to pulmonary artery (PA) uncoupling, which has been linked to adverse outcomes. Among patients with heart failure with preserved ejection fraction (HFpEF) and mildly reduced ejection fraction (HFmrEF), a highly heterogeneous group, the prognostic relevance of RV-PA uncoupling in forecasting longterm mortality is still not well defined. This study aimed to evaluate the association between RV-PA uncoupling and long-term mortality in a cohort of hospitalized HFpEF and HFmrEF patients. Materials and Methods. We performed a retrospective analysis based on a prospective registry of adult patients admitted with a primary diagnosis of AHF between 2015 and 2020. Eligible patients had a left ventricular ej...