In the summer of 2016, delegates from the German Society of Cardiology (DGK), the German Respiratory Society (DGP), and the German Society of Pediatric Cardiology (DGPK) met in Cologne, Germany, to define consensus-based practice recommendations for the management of patients with pulmonary hypertension (PH). These recommendations were built on the 2015 European Pulmonary Hypertension guidelines, aiming at their practical implementation, considering country-specific issues, and including new evidence, where available. To this end, a number of working groups was initiated, one of which was specifically dedicated to the definition, clinical classification and initial diagnosis of PH. While the European guidelines provide a detailed clinical classification and a structured approach for diagnostic testing, their application in routine care may be challenging, particularly given the changing phenotype of PH patients who are nowadays often elderly and may present with multiple potential causes of PH, as well as comorbid conditions. Specifically, the working group addresses the thoroughness of diagnostic testing, and the roles of echocardiography, exercise testing, and genetic testing in diagnosing PH. Furthermore, challenges in the diagnostic work-up of patients with various causes of PH including "PAH with comorbidities", CTEPH and coexisting conditions are highlighted, and a modified diagnostic algorithm is provided. The detailed results and recommendations of the working group on definition, clinical classification and initial diagnosis of PH, which were last updated in the spring of 2018, are summarized in this article.
