Endocrine Abstracts

Introduction: Hyperthyroidism produce changes in cardiac contractility, blood pressure, and systemic or pulmonary vascular resistance. In almost all cases these cardiovascular changes are reversible when the underlying thyroid disorder is recognised and treated. Pulmonary hypertension (PAH) has been associated with thyroid dysfunction, but primarily with hyperthyroidism. The vast majority of patients with this form of PAH are usually older with toxic multinodular goitre. The aim of this study was to determine the clinical correlates of PAH in patients with Graves’ disease (GD).

Methods: Our study is retrospective one concerning patients with GD referred for echography before using any treatment. PAH has been diagnosis when pulmonary artery systolic pressure was elevated.

Results: Among 22 consecutive patients with GD referred for echocardiography, six patients (27.32%) had PAH measured by continuous-wave Doppler echocardiography (pulmonary artery systolic pressure >35 mmHg). The patients with PAH had significantly higher pulmonaryvascular resistance (PVR), cardiac output, and TSH receptor antibody (TRAb) compared to those without. Pulmonary artery systolic pressure may had a good correlation with TRAb, but was not related to free T₄. All this patients have a reversible pulmonary hypertension after treatment.

Discussion: In addition to the effect of thyroid hormone on the cardiovascular system, autoimmune-mediated pulmonaryvascular remodelling may play a role in Graves’ disease-linked elevated pulmonary artery systolic pressure. An autoimmune process inducing endothelial damage with GD may play a key role. Future studies should focus on discovering the immunogenetic overlap between autoimmune thyroid diseases and PAH.

Conclusion: Study highlights the importance of considering hyperthyroidism as a cause of idiopathic PAH, and demonstrates the potential reversibility of its complications. At present, thyroid function tests should be considered in the investigation of all patients.