External validation of different clinical and echocardiographic scores to distinguish post- from precapillary pulmonary hypertension

Background Even though right heart catheterization (RHC) is the gold-standard method to characterise Pulmonary Hypertension (PH), it cannot be performed in all the patients with suspected PH. Clinical and echocardiographic scores have been developed to differentiate PH secondary to heart failure with preserved ejection fraction (PH-HFpEF) from pre-capillary PH. We aimed to compare the performance of non-invasive parameters in a population with suspected PH. Methods We retrospectively included consecutive patients who underwent RHC for suspected PH. Patients with a non-invasive evaluation clearly suggestive of left heart disease were excluded. We assessed the performance of non-invasive pulmonary vascular resistance (PVR), echocardiographic pulmonary to left atrial ratio (ePLAR), and Opotowsky, Richter, Berthelot, and D'Alto scores using the area under curve (AUC) of the receiver operating characteristic curves. Results Of the 142 included patients, 61 patients had pre-capillary PH, 49 had PH-HFpEF, and 32 patients did not meet invasive criteria for PH. We were able to perform the aforementioned scores in 71-100% of our patients. Using the original cut-offs, Opotowsky was the score that best predicted precapillary PH (96% sensitivity, 41% specificity, AUC .69), followed by D'Alto (98% sensitivity, 22% specificity, AUC .60) and Berthelot (32% sensitivity, 90% specificity, AUC .60). Richter score did not discriminate between phenotypes (AUC .50). Using optimised cut-offs, a Berthelot score < 9 predicted precapillary PH with 73% sensitivity and 74% specificity (AUC .73). Single echocardiographic parameters as non-invasive PVR (85% sensitivity, 59% specificity, AUC .72) and ePLAR (73% sensitivity, 76% specificity, AUC .75) showed better prediction performance than the composite studied scores. Conclusion Combined clinical and echocardiographic characteristics can be used to predict pre-capillary PH with moderate performance. The application of these non-invasive parameters in clinical practice can help refine referral to RHC in a population with clinically suspected PH.