Triiodothyronine levels in acute pulmonary embolism predict in-hospital mortality

ObjectiveTo assess the thyroid function in patients with acute pulmonary embolism, in order to evaluate the prognostic value of thyroid hormones.MethodsWe studied 31 consecutive patients with acute pulmonary embolism. Measured variables upon admission included the ratio of the partial pressure of oxygen in arterial blood to the inspired oxygen fraction (PaO2/FiO2), acute physiology and chronic health evaluation II score, risk stratification indices and plasma levels of triiodothyronine, free thyroxine, and thyroid stimulating hormone.ResultsPlasma levels of triiodothyronine were below normal level in 7 patients (22.6%). Plasma triiodothyronine correlated with PaO2/FiO2 (P < 0.05) and with acute physiology and chronic health evaluation II score (P < 0.01). In four patients (12.9%) who died, triiodothyronine levels were significantly lower (P < 0.01) than that in patients who survived. In contrast both groups had similar levels of free thyroxine, and thyroid stimulating hormone. Moreover, triiodothyronine levels negatively correlated with serum markers of right ventricular dysfunction. Accordingly, in multivariate logistic regression analysis, the only factors independently associated with an increased risk of death were triiodothyronine and PaO2/FiO2.ConclusionsOur preliminary data suggest that low plasma triiodothyronine is an independent predictor of in-hospital death in patients with acute pulmonary embolism.