Vanessa Farnan

Abstract Disclosure: M. Maher: None. R. McEvoy: None. V. Farnan: None. D.J. Tansey: None. S. McKenna: None. J. O'Connell: None. R. McQuillan: None. M. Griffin: None. J. Lyne: None. C. Magee: None. C. Traynor: None. A. Hudson: None. M.W. O'Reilly: None. A. Agha: None. M. Sherlock: None. C.M. Moran: None. Background: Amiodarone-induced thyrotoxicosis (AIT) is challenging to manage where conventional medical treatment fails. We report our experience using therapeutic plasma exchange (TPE) to prepare for salvage thyroidectomy. Clinical Cases: A 53-year-old man was diagnosed with AIT type 2 (FT4 45.3pmol/L, RR 12-22; TSH 0.02mU/L, RR 0.27-4.20) whilst on amiodarone, on a background of lamin A/C cardiomyopathy. He remained thyrotoxic despite carbimazole, prednisolone, iodine solution and cholestyramine. TFTs following 4 TPE sessions showed an improvement in TSH (0.03mU/L) and total T4 (129nmol/L, RR 63-151), despite rising FT4 (91.5pmol/L) and FT3 (12.56pmol/L, RR 2.43-6.01).A 47-year-old man was diagnosed with TRAb-negative AIT type 1 (FT4 51.2pmol/L, TSH 0.03mU/L) on a background of atrial fibrillation treated with amiodarone. He became progressively more thyrotoxic despite carbimazole, prednisolone, lithium and cholestyramine. Following 4 TPE sessions, TFTs demonstrated a reduction in FT4 (42.9pmol/L) and FT3 (10pmol/L, RR 3.1-6.8), along with normalisation of total T4 (155nmol/L, RR 66-181).A 56-year-old female was diagnosed with AIT type 2 (FT4 33.9pmol/L, TSH 0.02mU/L), whilst on amiodarone for ventricular fibrillation. She became rapidly and progressively more thyrotoxic despite carbimazole, prednisolone, iodine solution and cholestyramine (FT4 >100pmol/L). After 5 TPE sessions, TFTs showed a persistently elevated FT4 (>100pmol/L), FT3 (13.1pmol/L), and total T4 (318nmol/L). Lastly, a 65-year-old gentleman was diagnosed with AIT type 2 (FT4 >100pmol/L, FT3 18.4pmol/L, Total T4 >320nmol/L, TSH <0.01mU/L) on a background of atrial fibrillation that had been treated with amiodarone. FT3 showed a modest reduction (8.2pmol/L) following treatment with carbimazole and prednisolone; however, FT4 remained >100pmol/L. The patient developed acute decompensated heart failure and underwent TPE as a bridge to emergency thyroidectomy. Following 3 TPE sessions, TFTs demonstrated a reduction in FT4 (67.3pmol/L) and Total T4 (223nmol/L). All 4 patients underwent uneventful thyroidectomy and were subsequently rendered euthyroid with thyroxine. Heparin was administered during TPE in all cases. Conclusion: TPE is beneficial as a bridge to thyroidectomy in treatment-resistant AIT. Our cases demonstrate that the biochemical response is variable. Given the possibility for heparin to cause displacement of bound thyroid hormones, Total T4 may be a better biochemical indicator of response than free thyroid hormone(s) for patients on TPE. Presentation: 6/2/2024

Abstract Background Recurrent ischaemic strokes occur in 9-15% of patients within one year, the majority occurring within the first ninety days and up to 25% of patients who recover from a stroke are likely to have another stroke event within five years. Prompt introduction and optimisation of pharmacological therapy is essential for reducing recurrence. The mainstay of secondary prevention includes antiplatelet agents or anticoagulants, lipid lowering therapy and medications to optimise blood pressure and diabetes control. The primary aim of this study was to evaluate the current adherence to secondary prevention strategies in a tertiary stroke centre with a secondary aim of assessing achievement of target recommendations for LDL-C, HbA1c and blood pressure. Methods A retrospective chart review was conducted in a tertiary stroke centre. Patients were included if they were aged over 18 years and presenting to an outpatient stroke clinic with a diagnosis of an ischaemic stroke. Results A total of 49 patients were reviewed with 40 meeting our inclusion criteria. The median age was 69 years (range 42-90years) and 70% (n=28) were male. Four patients (10%) had a documented history of more than one ischaemic stroke. All patients were appropriately prescribed an anti-thrombotic agent and a cholesterol-lowering medication. 40% (n=16) of patients had LDL-C results above target (<1.8mmol/L; median 2; range 0.6-6.4). 30% (n=12) patients had a documented history of diabetes mellitus with a median HbA1c level of 42mmol/mol (range 28-87mmol/mol). No patient had a documented 24 hour blood pressure monitor result. Conclusion A significant number of patients attending their first follow-up appointment post stroke had inadequate lipid and diabetic control. Regular monitoring and target-driven therapy allow for regular optimisation of secondary prevention therapy which is crucial for improving clinical outcomes preventing recurrence.

Searchable abstracts of presentations at key conferences in endocrinology ISSN 1470-3947 (print) | ISSN 1479-6848 (online)

Introduction: Amiodarone-induced thyrotoxicosis (AIT) is a serious complication of amiodarone therapy, associated with high morbidity and mortality. Standard medical therapies are often insufficient in refractory cases, and therapeutic plasma exchange (TPE) has been proposed as a bridge to definitive thyroidectomy, although protocols for its use vary and detailed descriptions and definitions of response to therapy are limited. Case presentation: We report four cases of severe refractory AIT, prepared for thyroidectomy with TPE. Patients underwent three to five sessions using either albumin with saline, or combinations including fresh frozen plasma, as replacement fluids. TPE produced variable biochemical effects: free thyroxine (FT4) levels consistently fell during sessions but rarely normalised, while total thyroxine (TT4) normalised in some cases. In most patients, thyroid-stimulating hormone (TSH), previously suppressed for months, rose to detectable levels after only one to two sessions, suggesting a rapid reduction in biologically active thyroid hormone (TH) concentration. TPE was well tolerated overall, although transient coagulopathy and thrombocytopaenia occurred in two cases. All patients proceeded to successful thyroidectomy and achieved post-operative euthyroidism. Conclusion: TPE may provide temporary biochemical improvement and clinical stabilisation in refractory AIT, facilitating safe progression to thyroidectomy. However, its biochemical effects can be inconsistent and transient, and complications such as coagulopathy must be anticipated. Our experience supports the use of TPE as a valuable adjunct in selected patients with refractory AIT but illustrates that thyroidectomy should not be unnecessarily delayed in pursuit of complete TH normalisation or rigid biochemical targets.