Introduction: Patients with differentiated thyroid carcinoma have to undergo radical surgical treatment, which includes total thyreoidectomy, radioiodine therapy and a life-time supressive therapy with L-thyroxine. The aim of this study was a prospective evaluation of left ventricular hypertrophy during L supressive-thyroxine treatment in patients treated for differentiated thyroid carcinoma.
Material and methods: The examined group comprised 50 patients with differentiated thyroid carcinoma, treated by total thyroidectomy and 131I therapy. Echocardiographic measurements were needed for estimation of left ventricular mass and its index, according to recommendations of American Echocardiography Society.
Results: During two-years long supressive therapy we observed a significant rise in left ventricular mass. In woman group left ventricular mass was increased from 168 ± 39 g to 204 ± 45 g (p < 0.001) and in men from 205 ± 60 to 320 ± 21 g. Likewise, left ventricular mass index was increased in women group from 96 ± 18 g/m² to 116 ± 25 g/m² (p < 0.001) and in men group from 107 ± 37 g/m² to 158 ± 28 g/m². Simultaneous treatment with bisoprolol caused a regression of left myocardial hypertrophy. Already after 6 months of simultaneous treatment with L-tyroxin and bisoprolol, for left ventricular mass was reduced to normal: in woman 165 ± 35 g, and in men to 178 ± 38 g. Analogous results were obtained left ventricular mass index. After 6 months it was reduced to 94 ± 12 g/m² in woman and in men to 132 ± 32 g/m².
Conclusions:
1. In differentiated thyroid cancer patients, treated postoperatively with L-thyroxine supressive therapy, left ventricular hypertrophy is observed already during the first year of supressive therapy and progresses during the next year of treatment.
2 Addition of a beta-adrenergic antagonist to supressive doses of L-thyroxine causes a regression of left ventricular hypertrophy, thus, beta-adrenergic antagonists should be administred in this group of patients.
(Pol J Endocrinol 2007; 58 (5): 384-396)