Objective To establish an expert consensus on which criteria are the most appropriate in clinical practice to refer patients with systemic sclerosis (SSc) for right heart catheterisation (RHC) when pulmonary hypertension (PH) is suspected.

Methods A three stage internet based Delphi consensus exercise involving worldwide PH experts was designed. In the first stage, a comprehensive list of domains and items combining evidence based indications and expert opinions were obtained. In the second and third stages, experts were asked to rate each item selected in the list. After each of stages 2 and 3, the number of items and criteria were reduced according to a cluster analysis.

Results A literature search and the opinions of 47 experts participating in Delphi stage 1 provided a list of seven domains containing 142 criteria. After stages 2 and 3, these domains and tools were reduced to three domains containing eight tools: clinical (progressive dyspnoea over the past 3 months, unexplained dyspnoea, worsening of WHO dyspnoea functional class, any finding on physical examination suggestive of elevated right heart pressures and any sign of right heart failure), echocardiography (systolic pulmonary artery pressure >45 mm Hg and right ventricle dilation) and pulmonary function tests (diffusion lung capacity for carbon monoxide <50% without pulmonary fibrosis).

Conclusions Among experts in pulmonary arterial hypertension–SSc, a core set of criteria for clinical practice to refer SSc patients for RHC has been defined by Delphi consensus methods. Although these indications are recommended by this expert group to be used as an interim tool, it will be necessary to formally validate the present tools in further studies.