Continuous improvement of both hepatic and cardiac dysfunction by sequential plasma exchange in a patient with thyrotoxicosis and cardiogenic shock: a case report indicating the potential role of cardiohepatic interactions during thyroid storm.

Background: Thyroid storm (TS) complicated by cardiogenic shock is associated with high mortality due to the high incidence of multiple organ failure. It is recommended that TS patients with hepatic failure undergo plasma exchange (PE) and receive optimal anti-hyperthyroid medications. However, the effect of PE on cardiac dysfunction in TS patients has been unclear. Case summary: A 46-year-old woman was admitted to our hospital for dyspnoea and tachycardia. She was diagnosed with TS pursuant to Graves' disease complicated by acute decompensated heart failure (ADHF). Cardiac function was remarkably impaired [left ventricular ejection fraction (LVEF) = 15-20%], with rapid atrial fibrillation. Despite the management of both ADHF and hyperthyroidism, cardiogenic shock developed; therefore, veno-arterial extracorporeal membrane oxygenation (VA-ECMO) and intra-aortic balloon pumping (IABP) were initiated. Plasma exchange was performed after severe hepatic failure manifested on Day 2. After the first three PE treatments, cardiac and hepatic function improved immediately but deteriorated the next day. The improvement persisted after the fourth PE, and the patient was weaned from VA-ECMO and IABP on Days 10 and 11, respectively. She was discharged on Day 37, and her cardiac function was still normal 1.5 years later. Discussion: In hyperthyroidism, severe hepatic dysfunction is more likely to occur in patients with acute ADHF than in those without it. Plasma exchange has the potential to improve not only hepatic but also cardiac dysfunction under optimal antithyroid treatment, especially in patients with TS complicated by severe hepatic dysfunction.