NPPB and chronic kidney disease: Among the features that proved to be most significant for the predictive model were symptoms of right ventricular failure, TAPSE to sPAP ratio, 6MWT, presence of pericardial fluid, NT-proBNP serum concentration, right axis deviation in ECG, age, gender, comorbidities—diabetes and chronic kidney disease—and medications used in PAH therapy or to treat comorbidities.