[Thyroid dysfunction in patients with pulmonary arterial hypertension. A cohort study of 58 patients]

Thyroid disease (TD) is more prevalent in patients with pulmonary arterial hypertension (PAH) than in the general population. The frequency and the cause of this association are not well established. We aimed to quantify and analyze the incidence and characteristics of TD in a cohort of PAH patients (idiopathic or preferentially associated with systemic diseases) and review the literature.

Fifty eight PAH patients were prospectively studied, according to a previously established protocol (that included right heart catheterization); TSH, T(4), and antithyroglobulin and antiperoxidase antibodies were determined. TD was defined as an abnormal TSH level and/or elevated antithyroid antibodies (TAbs). Clinical, biological and hemodynamic variables were compared between patients with and without TD.

TD was detected in 30 patients (51%): high TSH levels were observed in 21 (36,21%); hyperthyroidism in 2 (3,45%); and TAbs in 16 of 54 (27,59%), 7 of whom were euthyroid. In the TD group, PAH evolution time was longer (4,62 vs 2,61 years; P=.005, CI 95%, 0,63-3,38), more patients were in functional class IV (13;43,3% vs 5;15,8%, P=.046, CI 95% ,0,05-11,75), cardiac output was lower (P=.032, CI 95%, 3,16-4,89) and epoprostenol treatment was more frequently used (14;46,6% vs 4;14,3%, P=.008, CI 95%, 1,46-18,85; OR=5,25).

The frequency of TD detected in this PAH cohort reaches 51% and it was associated with a longer evolution time of PAH and worse hemodynamic situation. Although epoprostenol was used more frequently in TD patients, a causal relationship with TD could not be established.