RESUMEN
Abstract We report the case of a patient with symptomatic pulmonary hypertension (PH) associated with diffuse systemic sclerosis (SSc) whose initial assessment suggested a group 3 (clinical classification) PH. The patient had a history of drugs/toxins consumption, which contributed to the development of intrinsic pulmonary vascular disease. This changed the panorama towards the diagnosis of pulmonary arterial hypertension (PAH), with important therapeutic and prognostic implications. In fact, the excellent clinical, laboratory and hemodynamic response to therapy confirmed the hypothesis of a case of drug-associated PAH (DPAH) in a patient with diffuse SSc and lung disease. Considering the presence of DPAH, it was deemed necessary to assess acute vasoreactivity during right heart catheterization (RHC). If criteria were met, the clinical scenario may change towards a favorable and sustained clinical and hemodynamic response with oral calcium channel blockers. However, the response to inhaled nitric oxide was negative in our patient and the therapeutic strategy with dual oral combination therapy with tadalafil and ambrisentan was continued. After six-months of therapy the patient significantly improved, from a high to a low risk of one-year mortality.