Non‐Invasive <scp>TAPSE</scp>/<scp>PASP</scp> Ratio as a Predictor of Postoperative Low Cardiac Output Syndrome in Mitral Valve Surgery

ABSTRACT Background Ventricular‐arterial (V‐A) coupling, the interaction between the heart's contractile function and the arterial system's resistance, is crucial for understanding cardiovascular health and disease. This coupling can be quantified by end‐systolic elastance and arterial elastance, indicating the efficiency of the cardiovascular system. Disruptions in this balance, particularly with right ventricular (RV) dysfunction, have clinical significance, especially in diseases like pulmonary arterial hypertension, heart failure, and valvular heart diseases. The study of V‐A coupling is particularly important for evaluating cardiovascular performance in these conditions. Methods This observational, cross‐sectional study included patients undergoing mitral valve replacement (MVR) with or without aortic or tricuspid valve replacement at the Instituto Nacional de Cardiología Ignacio Chávez. Non‐invasive measures of V‐A coupling were assessed using the tricuspid annular plane systolic excursion (TAPSE) and systolic pulmonary artery pressure (PASP), which were combined into the TAPSE/PASP ratio. Statistical analysis was performed using logistic regression to explore the relationship between this ratio and postoperative outcomes. Results Patients with a TAPSE/PASP ratio ≤ 0.31 showed a higher incidence of low cardiac output syndrome (LCOS) (36.1% vs. 11.3%, p = 0.003). The ratio was significantly associated with impaired RV function and higher pulmonary pressures. Conclusions The TAPSE/PASP ratio is a valuable non‐invasive predictor of postoperative complications, particularly LCOS, in patients undergoing MVR. A lower ratio indicates a higher risk and may guide postoperative management strategies to optimize patient outcomes. Further research is needed to confirm these findings and explore long‐term prognostic implications.