Pulmonary hypertension is frequent in hyperthyroidism and normalizes after therapy.

BACKGROUND

In recent years, many authors have described several cases revealing an association between hyperthyroidism and pulmonary hypertension. This observational study was designed to evaluate the prevalence of pulmonary hypertension in hyperthyroidism and to determine the role of methimazole in regulating pulmonary vascular resistance in these patients.

METHODS

We studied 114 patients, 78 women and 36 men, whose mean age was 51+/-13years. Forty-seven had Graves' disease and 67 had a nodular goiter. All subjects were ambulatory and were recruited in a consecutive order. The control group (group 2) included 20 healthy subjects matched for age and sex. Transthoracic Doppler echocardiography was performed and systolic pulmonary artery pressure (PAPs) was determined by the tricuspid regurgitation method using the Bernoulli's equation. We performed a 120-day follow-up in the patients with pulmonary hypertension and we divided them into two subgroups: group 1A (n=33), patients treated with methimazole, and group 1B (n=17), subjects treated with partial thyroidectomy.

RESULTS

We found a mild pulmonary hypertension in 50 patients in group 1 (43%) and in none of those in the control group. The mean+/-SD PAPs was 27.77+/-6.56 in group 1 and 21.32+/-2.55 in group 2. A negative correlation was found between the T.S.H. value and the level of PAPs (r=-0.85; p<0.001). During the follow-up, group 1A went from a PAPs value of 34.3+/-3.2 to 29.2+/-3.3 after 15days of therapy and group 1B from 34.3+/-3.0 to 34.1+/-2.9 (p<0.001).

CONCLUSIONS

The results of the present study demonstrate a frequent association between hyperthyroidism and mild and transient pulmonary hypertension. Subjects treated with methimazole have a more rapid drop in PAPs.