Rf61 Predicting the Pressure of the Total Cavo-Pulmonary Connection: Clinical Testing of a Mathematical Equation

Abstract

Introduction: Among the factors which determine Fontan outcome, the total cavo-pulmonary pressure plays a fundamental role. Some authors advocate the use of a dedicated formula to predict the Fontan pressure. The aim of this work is to test the predictive and the clinical value of the mentioned formula through a retrospective clinical study. Methods: Data of all patients undergoing pre-Fontan catheterization and Fontan completion at our institution were collected. Pre-Fontan catheterization data were used to calculate the predicted Fontan pressure. Predicted values were compared to the pressure measured in the acute phase after the Fontan completion and correlated to patients’ clinical outcomes. Results: 124 Fontan patients were retrospectively enrolled with a median age at the Fontan of 35.00 [31.00- 41.25] months, median weight of 13.00 [11.68-14.10] Kg. Fontan conduct was fenestrated in 78 patients. Fontan failure (composite of death, need for transplant, takedown) was observed in 11. A statistically significant correlation between measured and predicted data for the overall population (p = 0.0114) but with a poor correlation coefficient (r2 = 0.014). In the case of Fontan predicted pressure lower than 17.59 mmHg, the formula was able to identify a good clinical outcome in the acute phase with a sensitivity of 92% and specificity of 31%. Conclusion: The proposed formula showed a poor capability in estimating the actual pressure into the Fontan system and in identifying patients needing fenestration. However, a cut-off value lower than 17.59 mmHg showed a fair sensitivity to identify patients with a good acute clinical outcome.