Echocardiographic Diagnosis of Postcapillary Pulmonary Hypertension: A RIGHT1 Substudy

Background: Pulmonary hypertension is observed in 70% of patients with left ventricular (LV) dysfunction. Right heart catheterization is the gold standard for a complete evaluation of Pulmonary Hypertension (PH); however, echocardiography represents a powerful initial diagnostic tool. The aim of our study was to evaluate the accuracy of echocardiography for the diagnosis of postcapillary PH, i.e., due to increased left ventricular filling pressures. Methods and Results: We recruited patients with a diagnosis of PH from the RIGHT1 study (Right heart invasive and echocardiographic hemodynamic evaluation in Turin 1). Transthoracic echocardiography was performed within 60 min of cardiac catheterization. High LV filling pressures were defined by a pulmonary arterial wedge pressure (PAWP) greater than 15 mmHg. We assessed numerous morphological and functional features of LV, and their association with PAWP. 128 patients were diagnosed with PH. We observed a significant association between PAWP, the left atrial volume indexed by BSA (LAVi, R2 = 0.27; p < 0.0001) and the E/e’ ratio (R2 = 0.27; p < 0.0001). With these parameters, we implemented a diagnostic algorithm to identify high ventricular filling pressures in PH patients. The application of this algorithm could help identify patients with a diagnosis of postcapillary PH due to high ventricular filling pressures (E/E’ > 15). Conclusions: The echocardiographic parameters with the best association with PAWP in PH patients are E/e’ and LAVi. For these patients, our diagnostic algorithm could improve the diagnostic precision for the definition of subgroups.