Background: Along with advances in end‑ stage heart failure (HF) treatments, such as heart transplantation (HTx) and ventricular assist devices as destination therapy, there is an increasing need to define scoring systems for selecting the most suitable candidates for these interventions. Furthermore, constraints in donor number necessitate the precise evaluation of patients before candidacy for HTx. Methods: We enrolled eighty patients with severe symptomatic HF, left ventricular ejection fraction <30%, and New York Heart Association Functional Class III– IV. All patients underwent right heart catheterization for hemodynamic assessment and were followed for 18 months. We defined cSVO2 as the ratio of right atrial pressure (RAP) to mixed venous saturation. Results: During follow‑ up, 13 patients died, 7 patients underwent HTx, and 36 patients were hospitalized with signs and symptoms of HF. Among hemodynamic parameters, RAP and cSVO2 had strongest association with prognosis and clinical worsening. Conclusion: Defining predictors of clinical worsening has great importance in HF. The current study showed cSVO2 as a strong predictor of clinical worsening in end‑ stage HF.