Mitral Valve Prolapse in Autoimmune Thyroid Disease: An Index of Systemic Autoimmunity?

Abstract

A coexistence of mitral valve prolapse (MVP) with autoimmune thyroid disease (AITD) has been described, but there are not sufficient data to explain this association. The aim of the present study was to investigate the prevalence of MVP in patients with AITD and to evaluate whether any correlation between MVP and certain immunological parameters exists. M-mode, two-dimensional Doppler echocardiography was performed in 29 patients with Graves' disease (GD), 35 with Hashimoto's thyroiditis (HT), 20 with nonautoimmune goiter, and 30 normal controls. Serum samples were examined for antinuclear antibodies (ANA), antibodies against extractable nuclear antigen (ENA), antiphospholipid antibodies (aCL), rheumatoid factor (RF), thyroid autoantibodies (TAAb), immunoglobulins and C3, C4. Eight of 29 GD patients and 8 of 35 HT patients had MVP, while none of the control group and 2 of 20 of the simple goiter group had MVP (p < 0.05). ANA were detected at low titers in 5 of 8 in MVP(+) GD versus 3 of 21 in MVP(-) GD (p < 0.05). In the HT group the MVP(+) patients had a significantly higher incidence of ANA and ENA, 5 of 8 and 2 of 8 versus 5 of 27 and 0 of 27 of MVP(-) patients, respectively, p < 0.05. A statistically significant higher incidence of aCL was found in HT MVP(+) patients. (3/8) versus HT MVP(-) 1/27, p < 0.05. RF levels (immunoglobulin A [IgA]) were significantly higher in MVP(+) patients. The association of MVP with nonorgan-specific autoantibodies indicates that MVP may also be an autoimmune disease. It is possible that patients with AITD who also have MVP may be at an increased risk to develop systemic autoimmunity.

Thyroid Disease and the Heart

“…The latter in turn may predispose to enlargement of the left atrium and atrial fibrillation. 90 Among people Ͼ60 years of age, a low TSH level is associated with increased risk for atrial fibrillation, which in turn could lead to congestive heart failure. 83,91 It is interesting to speculate on the basis of the high prevalence of pulmonary artery hypertension that many of the signs of heart failure, such as neck vein distension and peripheral edema, may be caused by right heart strain.…”

Mitral valve prolapse in young healthy individuals. An early index of autoimmunity?

“…2 Some studies report an increased prevalence of MVP in heritable connective tissue disorders 3 and in organspecific autoimmune disorders such as autoimmune thyroid diseases. [4][5][6][7] Specifically, in patients with autoimmune thyroid diseases, we have previously reported an increased prevalence of further indices of autoimmunity in the group who also had MVP. 4 Some further studies have also reported an increased frequency of MVP in systemic lupus erythematosus (SLE); 8,9 and recently in Crohn's disease.…”

Thyrotoxic cardiac disease

“…Hyperthyroidism can also unmask valvular heart disease and produce worsening mitral or tricuspid regurgitation [ 26 ]. Autoimmune thyroid diseases, including Graves' disease and Hashimoto's thyroiditis, are associated with an increased prevalence of mitral valve prolapse, enlargement of the left atrium, and development of atrial fi brillation [ 27 ]. Hyperthyroidism complicating pregnancy imposes a further increase in the cardiac work required to maintain markedly increased Congestive heart failure cardiac output.…”