Hyperthyroidism Associated Congestive Heart Failure: A Case-Control Study

Hyperthyroidism has been associated with cardiomyopathy and heart failure (HF). This study aims to evaluate clinical, laboratory and echocardiographic para-meters, at admission and 12 months fol-lowing euthyroidism restoration, in patients with hyperthyroidism-associated HF. Mechanisms un-derlying hyperthyroidism-associated HF and the outcomes of echocardiographic parameters along the study period are both discussed. Materials Methods: Patients with newly di-agnosed overt hyperthyroidism and HF (Group 1), age and sex-matched euthyroid HF subjects (Group 2), and a control group were enrolled. Results: In the 38-month study period, 56 pa-tients were admitted for hyperthyroidism-associated HF, of whom 71% had a pre-existing, mainly hypertensive, cardiomyopathy vs 68% of Group 2 subjects. Mean heart rate was signifi-cantly higher in Group 1 than Group 2 (127±38 vs 110±17bpm; P 0.02); 30 Group 1 (54%) and 16 (29%) Group 2 patients presented with atrial fi-brillation. At admission, left ventricular ejection fraction (LVEF), end diastolic (LVEDD) and end systolic (LVESD) diameters were lower, whilst LV mass (LVM), interventricular septum thick-ness (IVST) and LV posterior wall thickness (LVPWT) were increased in both Groups com-pared to controls. At the end of the study, de-spite achievement of euthyroidism in all hyper-thyroid patients, mean LVEF was not significant-ly different in Group 2 but was significantly lower in Group 1 patients compared to controls; LVM, IVST and LVPWT did not change in both study groups. Conclusion: In our series, newly diagnosed hyperthyroidism-associated HF had 2.4% preva-lence. At the end of the study, LVEF significant-ly improved in euthyroid, but not in hyperthy-roidism-associated HF patients compared to con-trols.