A minimally invasive pre-operative measure of total pulmonary resistance is associated with early adverse outcomes following total cavopulmonary connection.

AIMS: Survival following total cavopulmonary connection (TCPC) is influenced by pre-operative haemodynamics. We developed a minimally invasive method to measure total pulmonary resistance (TPR) at the bidirectional cavopulmonary connection (BCPC) stage, reflecting the combined pulmonary impedance of the TCPC circulation. We evaluated whether TPR predicted early Fontan failure [EFF; death, TCPC take-down, emergency fenestration, or mechanical circulatory support (MCS) ≤ 6months post-TCPC] or prolonged post-operative intensive care unit (ICU) stay (>14 days).

METHODS AND

RESULTS

TPR was derived using jugular venous pressure as a surrogate for central venous pressure (CVP) and pulmonary blood flow (Q p) measured non-invasively from cardiovascular magnetic resonance (CMR). Indexed TPR (TPRi) was calculated as CVP/Q p indexed to body surface area. Logistic regression evaluated predictors of early post-TCPC outcomes. Receiver operating characteristic (ROC) analysis assessed TPRi discrimination for EFF or the composite endpoint of EFF or prolonged ICU stay [early adverse outcome (EAO)]. Of 232 patients with BCPC undergoing CMR, 96% (n = 223) proceeded to TCPC. TPR data were available in 204 patients. On multivariable analysis, TPRi (adjusted OR 1.28, P = 0.030) and isomerism [adjusted odds ratio (OR) 14.34, P = 0.002] were independently associated with EFF. Both TPRi (adjusted OR 1.37, P = 0.001) and isomerism (adjusted OR 14.53, P = 0.001) also independently predicted EAO. ROC analysis identified optimal TPRi thresholds of ≥5.78 WU·m2 for EFF (sensitivity 80%, specificity 54%) and ≥5.7 WU·m2 for EAO (sensitivity 75%, specificity 53%).

CONCLUSION

TPRi, calculated by combining pressure and flow data at the BCPC stage, independently predicts early adverse post-TCPC outcomes and may help identify high-risk patients without cardiac catheterization.