High doses of intravenous (iv.) glucocorticoids (GCs) are commonly used as a treatment for many autoimmune and inflammatory disorders. According to the European Group on Graves' Orbitopathy (EUGOGO) guidelines, intravenous methylprednisolone (IVMP) is an accepted first-line agent for active, moderate-to-severe and very severe Graves' orbitopathy (GO). This treatment is proven to be more efficient and safer than oral GCs. However, some patients may experience adverse cardiovascular effects during the administration of iv. GCs, which in rare cases may even be fatal. There are limited data, mostly obtained from case reports, reporting the occurrence of cardiac arrhythmias, acute myocardial infarction or heart failure. Increased heart rhythm (HR) has drawn attention of researchers as a possible adverse effect correlated with IVMP. During this study, investigators performed 72-hours of Holter ECG and ambulatory blood pressure monitoring (ABPM) to evaluate the impact of IVMP on patients with moderate-to-severe GO, concerning HR and blood pressure (BP) changes. In order to elucidate possible mechanism of observed changes, researchers investigated the level of potassium in serum and urine and catecholamines (epinephrine, norepinephrine) in serum. All patients were treated routinely according to EUGOGO recommendations with standard doses of methylprednisolone with standard recommended schedule. Inclusion criterion for the therapy was according to EUGOGO guidelines active, moderate-to-severe and active GO (12 pulses of IVMP 6x0.5g followed by 6x0.25g every week).

The clinical status of patients was evaluated before each pulse, including blood pressure monitoring, glucose level monitoring and symptoms of infection. HR and BP was measured continuously for 3 consecutive days (the day before, the day of IVMP and the day after IVMP) during 1st, 6th and 12th IVMP pulse, using 24-hour Holter ECG and ABMP. Serum laboratory tests for potassium, epinephrine and norepinephrine were measured 3 times the day before and the day of first IVMP pulse and 1 time the second and sixth day after 1st IVMP. Additionally, urine samples for potassium were collected 5 times the day of first IVMP pulse and 1 time the second and sixth day after 1st IVMP.

Inclusion Criteria:

• active, moderate-to-severe GO according to EUGOGO classification
• euthyroidism
• completion of 12 IVMP pulses.

Exclusion Criteria:

• cardiovascular morbidity (such as chronic heart failure and/or coronary heart disease)
• uncontrolled hypertension (defined as systolic blood pressure (SBP) more than 140 mmHg and/or diastolic blood pressure (DBP) more than 90 mmHg)
• contraindications to IVMP therapy
• previous GCs treatment in the last 6 months.

Patients admitted to the clinic for routine treatment of active, moderate-to-severe GO

The collected data will be shared in a publication. It includes all laboratory results from all points of evaluation, results of 72-hour Holter ECG and 72-hour ABPM.

The results of the study will be published in 2020