Patients with autoimmune disease, and in particular limited systemic sclerosis (CREST syndrome), are at risk of developing pulmonary artery hypertension (PAH) which is associated with a poor prognosis. With improvements in therapy offering improved survival and functional capacity, there has been an emphasis on screening to identify patients at risk. Assessment of patients during exercise may enable early identification of patients with this condition.
Aims and methods: We aimed to assess the ability of exercise stress echocardiography to evaluate the change in pulmonary artery pressure in 51 patients with autoimmune disease (systemic lupus erythamatosus (SLE), limited systemic sclerosis (LSS or "CREST") and diffuse systemic sclerosis (DSS)). Systolic pulmonary artery pressure (sPAP) was estimated using interrogation of the tricuspid incompetence jet before and after exercise. PAH was classified as normal, mild, moderate or severe using echocardiographic assessment of sPAP.
Results: We were able to estimate pre-exercise and post-exercise sPAP in 92% and 90% of patients, respectively. Pulmonary pressures rose or remained unchanged in all screened individuals, with a mean rise during stress of 14.1mmHg (+/-1.1). Pulmonary artery pressure rose significantly in each of three subgroups (p<0.05). Stress echocardiography demonstrated PAH (using a cut-off of >35mmHg) in 59% of all individuals with systemic autoimmunity.
Conclusion: Stress echocardiography is a useful tool in identifying individuals with autoimmune disease who may have underlying pulmonary arterial disease that may be amenable to therapy. We noted a consistent elevation in sPAP across all autoimmune subtypes, suggesting an abnormal pulmonary vascular response to exercise exists in these patients.