How could we improve the increased cardiovascular mortality in patients with overt and subclinical hyperthyroidism?

Abstract

Over the past five years several meta-analyses have evaluated the cardiovascular mortality in patients with hyperthyroidism. They assessed various studies in which different inclusion criteria were used for the analysis of the cardiovascular mortality. More selective criteria have been used in recent meta-analyses. Only prospective cohort studies were included and only cohorts using second and third generation TSH assays were chosen. In addition, only the studies where the TSH evaluation was repeated during the follow-up were selected. The results of these recent meta-analyses provide evidence that overt and subclinical hyperthyroidism, particularly in patients with undetectable serum TSH, may increase the cardiovascular mortality. However, still today, the results remain inconclusive and not sufficient enough to recommend treatment for patients with low-detectable serum TSH. The high cardiovascular risk and mortality in presence of thyroid hormone excess suggest that this dysfunction is an important health problem and requires guidelines for the treatment of patients at high cardiovascular risk. Rigorous studies are necessary to evaluate the effects of the various causes of hyperthyroidism on the clinical outcomes. Randomized controlled clinical trials are needed to assess the benefits of treatment to improve the cardiovascular mortality and morbidity of mild and overt hyperthyroidism.