The Role of Fluid Challenge to Diagnose Left Ventricular Diastolic Dysfunction during Right Heart Catheterization: A Systematic Review and Bayesian Hierarchical Network Meta-Analysis

BackgroundFluid challenge during right heart catheterization (RHC) is used to reveal occult left ventricular diastolic dysfunction (LVDD) in patients with normal resting hemodynamics.However, validation of diagnostic thresholds is lacking. MethodsA systematic review and Bayesian network meta-analysis was performed to analyze continuous hemodynamic responses across three predefined phenotypes: no diastolic dysfunction (nLVDD), resting diastolic dysfunction (rLVDD), and occult diastolic dysfunction (oLVDD).These outcomes comprised pulmonary arterial wedge pressure (PAWP) measured prior to fluid challenge (baseline PAWP), PAWP measured after fluid challenge (post-fluid PAWP), and the difference between these measures (PAWP).Posterior predictive ROC analysis evaluated performance for identifying hemodynamic phenotypes. ResultsSixteen studies (n=2,176) were included.Post-fluid PAWP had strong performance in differentiating oLVDD or rLVDD from nLVDD (AUC 0.992, 95%CrI 0.986-0.996,sensitivity 0.96 and specificity=0.97) with a diagnostic threshold of 16.4 mmHg.PAWP also distinguished oLVDD or rLVDD from nLVDD (AUC 0.850 95% CrI 0.824-0.874),as well as oLVDD from nLVDD (AUC 0.931, 95% CrI 0.915-0.946)with a PAWP threshold of 5.5 mmHg.The optimal baseline PAWP threshold to differentiate between groups was approximately 12 mmHg, but sensitivity was poor. ConclusionsPost-fluid PAWP was highly sensitive and specific in differentiating oLVDD or from nLVDD.Additionally, PAWP performed well in differentiating between oLVDD and nLVDD.Baseline PAWP was not sensitive in ruling out oLVDD.These results support a lower diagnostic threshold than current recommendations, consideration for incorporating PAWP, as well as a lower value for normal PAWP in the diagnosis of postcapillary pulmonary hypertension.