Cardiac Symptoms in Patients With Treated Graves' Disease

Hyperthyroidism is a condition with increased production of thyroid hormone from the thyroid gland. Hyperthyroidism affects the heart's inotropy (contractile force) and chronotropy (rhythm). Therefore, patients often experience symptoms such as increased/irregular heart rate, pounding heartbeats, and shortness of breath. The cardiac symptoms often improve when hyperthyroidism is treated and biochemical euthyroidism is achieved. However, knowledge of the long-term effects on the heart is limited. Existing studies have generally shown that patients with hyperthyroidism have an increased morbidity and mortality.

The investigators conducted a questionnaire survey which showed that about 38% of patients with Graves' disease continue to experience cardiac symptoms even months after normalization of thyroid hormone concentrations in the blood. This observation supports the presence of a persistent cardiovascular dysfunction, which may be due to a modulation of genomic or non-genomic factors with an effect on the cardiovascular system. These reflections are the focus of this clinical study. The aim of the study is to investigate the possible pathophysiology for this new "syndrome" in biochemically euthyroid patients. It is not a repetition of previous similar experiments.

Active, Not Recruiting

This study is active but is not currently recruiting participants.

Key information

Conditions

Graves Disease Arrhythmias, Cardiac Autoimmune Diseases Cardiac Arrhythmias Cardiac Structure and Function Cardiovascular Diseases Endocrine System Diseases Exophthalmos Eye Diseases Goiter Heart Diseases Hyperthyroidism Immune System Diseases Orbital Diseases Pathologic Processes Pathological Conditions, Signs and Symptoms Thyroid Diseases

Age range

18 year–55 year

Sex eligibility

All sexes

Study type

Observational

Primary location

Rigshospitalet

Copenhagen, Denmark

About this study

Cardiac symptoms are common i patients with Graves' disease. These symptoms often disappear when hyperthyroidism is treated. However, a subgroup of patients with Graves' disease experiences persisting cardiac symptoms after treatment. The aim of the study is to describe these symptoms and investigate their origin.

A total of 75 patients are included in the study. Patients were recruited from the Department of Nephrology and Endocrinology at Copenhagen University Hospital Rigshospitalet and the Department of Internal Medicine, Section of Endocrinology at Herlev Gentofte Hospital, Denmark. The patients were identified by extracting a list of patients with the International Classification of Diseases 10 codes (ICD 10 codes) E050 and E059. Also, a list of patients with positive thyrotropin receptor antibody (TRAbI measurements was extracted.

All patients had a thorough cardiac work up including blood samples, 12-lead resting electrocardiogram, 24-hour electrocardiogram monitoring (Holter), transthoracic echocardiography, and exercise stress test. The focus was to investigate whether the cardiac symptoms could be explained by structural or functional changes of the heart or by cardiac arrhythmias.

All patients were questioned about their symptoms including: type of cardiac symptoms, frequency and when they occured. The focus was to gain knowledge on the clinical presentation of cardiac symptoms in the subgroup.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

Patient with Graves' disease
Between the ages of 18 and 55 years
Has been euthyroid for at least three months prior to inclusion
Experiences cardiac symptoms

Exclusion criteria

Cardiovascular disease
Deemed unsuitable by project staff (e.g. due to language problems)
Pregnancy
Alcohol abuse or other abuses

Treatment and study plan

Primary outcomes

Cardiac changes

Time frame: The cardiac examinations were performed during three study visits which extended over a period of approximately half a year.

The patients were examined for cardiac arrhythmias and structural and functional changes of the heart with resting 12-lead ECG, 24-hour ambulatory ECG monitoring, transthoracic echocardiography, and exercise stress test.

ECG analyses included: heart rate, PR-interval, QRS-duration, and QT-interval. Any presence of abnormal cardiac axis, bundle branch block, atrioventricular (AV) block, ventricular hypertrophy or atrial enlargement was noted.

Analysis of the 24-hour ECG recording including heart rate, detection of arrythmia, heart block, and reported symptoms.

The echocardiographic analysis consisted of the following measurements: left ventricular dimensions, left ventricular volumes, left ventricular function, left atrial volume, right ventricular dimensions, right ventricular function, and pulmonary artery pressure.

Analysis of the exercise stress test included blood pressure, heart rate, and ECG-changes indicating myocardial ischemia and arrhythmias.

Sponsors and collaborators

Lead sponsor

Ulla Feldt-Rasmussen

Other

Registry information

Official study title

Persistent Cardiac Symptoms in Patients With Adequately Treated Graves' Disease

Acronym: CARD-GRAVES

Important dates

Study start: 2021
Primary completion: 2025
Study completion: 2025
First posted: Apr 3, 2025
Registry last updated: Apr 3, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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Active, Not Recruiting