Hyperthyroidism as a cause of pulmonary arterial hypertension: a prospective study.

The authors assessed the prevalence of pulmonary arterial hypertension (PAH) in patients with hyperthyroidism and evaluated the response to treatment of the thyrotoxicosis. They assessed the pulmonary artery systolic pressure (PASP) at rest (estimated by echocardiography) in 23 consecutive patients diagnosed with hyperthyroidism due to Graves' disease or toxic multinodular goiter. Twelve of 23 patients (52%) did not show antithyroglobulin and antithyroperoxidase antibodies. Seventeen patients were followed up for at least 9 months after achieving a stable euthyroid status. Fifteen (65%) patients demonstrated PAH at admission. Four patients were lost to follow-up; therefore they were able to evaluate 17 patients serially with echocardiography. Sixteen patients normalized their PASP value: 13 after methimazole, 2 after total thyroidectomy, and 1 after I-131 treatment. In 1 patient no significant change in PASP was observed. This patient experienced an acute myocardial reinfarction during follow-up. They found a higher prevalence than that previously reported in observational studies. In addition, they demonstrated that the PAH reverses after correction of hyperthyroidism. Elevated PASP at rest on echocardiography may be considered a frequent finding of thyrotoxicosis. Moreover, the data seem not to support an autoimmune pathogenesis for PAH.