CARDIAC SARCOIDOSIS

The heart can be affected by sarcoidosis in two ways. Firstly, sarcoidosis can occur in the heart muscle itself (cardiac sarcoidosis). Secondly, the heart may be indirectly affected as a result of sarcoidosis in the lungs (pulmonary hypertension). Both conditions can have serious consequences.

The information on this page has been compiled with the help of sarcoidosis specialists Dr V. Kouranos, Dr. L. Williams & Dr. S. Agarwal, Consultant Cardiologists, Dr. K. Tweed, Consultant Radiologist and Dr. M. Thillai, Consultant Chest Physician (all Cardiac Sarcoidosis Unit, Royal Papworth Hospital) with additional comments from Dr. M. Wickremasinghe, Consultant Respiratory Physician and Dr. A. Varnava, Consultant Cardiologist (both Imperial College Healthcare NHS Trust).

Download the Leaflet:

Sarcoidosis and The Heart

Part 1 and Part 2 of our Cardiac Sarcoidosis Video with Dr Muhunthan Thillai

Techniques to Understand Cardiac Sarcoidosis

International guidelines suggest the performance of a 12-lead ECG in all sarcoidosis patients as a screening tool on top of obtaining a history of cardiac symptoms. A Holter monitoring and echocardiogram will be performed depending on each case individually. All suspected cardiac sarcoidosis patients should undergo a cardiac MRI and/or a cardiac FDG-PET. The available diagnostic tests are described below:

Most newly diagnosed sarcoidosis patients will have an ECG, Holter monitor and echocardiogram. Suspected cardiac sarcoidosis patients may go on to have further diagnostic tests. Most of these are described below.

ECG (Electrocardiogram):  This provides information about the electrical conduction system of the heart, as well as the heart rate and heart rhythm. Conduction system abnormalities and ventricular tachycardias can be identified in cardiac sarcoidosis patients.

Holter monitor:  A Holter monitor is a small, portable ECG device that takes a continuous recording of your heart rhythm over a longer period of time (usually 24 hours but sometimes longer). It is particularly useful to identify any rhythm disturbances associated or not with your symptoms (e.g. very fast or slow heart beats or any abnormal rhythms).

Echocardiogram (Echo):  This uses ultrasound waves to create images which show the pumping function and structure of the muscular heart chambers and the function of the heart valves. It also allows measurement of the blood pressure within the heart vessels (to look for pulmonary hypertension).

Magnetic Resonance Imaging (MRI): This scan is the most important diagnostic tool to identify involvement of sarcoidosis in the heart. As part of the protocol you will be injected with a special dye. Delayed enhancement of the dye in the myocardial tissue suggests areas of damage (fibrosis and/or inflammation) of the heart muscle. MRI images also provide accurate information (even superior than echocardiography) about the myocardial structure and function.

Cardiac Flurodeoxyglucose – Positron Emission Tomography (FDG-PET): FDG-PET scans create images that can identify any active inflammation within the heart muscle and can help to guide immunosuppressive treatment. A specific diet preparation and prolonged fasting (18 hours) is required for the performance of the cardiac FDG-PET scan. (this will be explained to you beforehand).

Nuclear Medicine Scans: Thallium scintigraphy or Rubidium perfusion scans are used for the detection of myocardial damage in the heart muscle. They are often combined with cardiac FDG-PET scans.

Clinical Electrophysiology Studies:  A catheter is used to map the conduction system of the heart. This can uncover abnormalities which may predispose abnormally slow heart rates, as well as any abnormally fast or dangerous heart rhythms which can arise from areas of inflammation or scarring.

Biopsy of the Heart: This option will be selected in rare cases when the diagnosis of cardiac sarcoidosis is not supported by typical manifestations or imaging.

Blood Samples: The following may be tested:

• angiotensin converting enzyme (ACE)
• brain natriuretic peptide (BNP), or NTpro-BNP
• high sensitive troponin

Treatment For Cardiac Sarcoidosis

Timely diagnosis and treatment with medication is important for a favourable prognosis. Your doctor may prescribe medication to suppress the inflammation related to your sarcoidosis. These drugs suppress the inflammation but do not medicate the heart itself.

Sarcoidosis specific medications:

• Corticosteroids (usually prednisolone tablets) may be used for a number of years. Some patients may require low doses longer term, in combination with other forms of immunosuppression. In severe cases intravenous steroids may be used first before switching to tablets.
• Other medicines are also used that suppress the immune system, for example: methotrexate, mycophenolate or azathioprine.

You may be prescribed medications that help regulate the heart rhythm or to treat heart failure. Some of the main medications include:

• ACE inhibitors
• Angiotensin-2 receptor blockers (ARBs or AIIRAs)
• Beta blockers
• Mineralocorticoid receptor antagonists
• Diuretics
• Ivabradine
• Sacubitril valsartan
• Hydralazine with nitrate
• Digoxin
• SGLT2 inhibitors
• Amiodarone

Patients presenting with severe heart failure or with severe ventricular arrhythmias will require a defibrillator (ICD) as secondary prophylaxis. An ICD may also be implanted in patients with advanced conduction abnormalities or those at high risk of a major arrhythmic event.

Heart transplant may be considered in extreme cases. This is very rare.

Pulmonary Hypertension

Pulmonary hypertension means high blood pressure in the pulmonary arteries; vessels that supply the lungs with blood. It’s a serious condition that can damage the right side of the heart. It is more common in sarcoidosis patients with advanced lung or heart disease as well as patients experiencing major or recurrent blood clots in the lungs. However, it can also happen due to direct inflammation of the pulmonary vessels as well as obstruction of the blood flow within the pulmonary arteries from enlarged mediastinal lymph nodes. The increased pressure within the blood vessels in the lungs can then overload the right ventricle and result in right ventricular heart failure. This can occur in up to 15% of all patients with sarcoidosis.

Techniques to Understand Pulmonary Hypertension

Echocardiogram (Echo): This uses ultrasound waves to create images which show the pumping function and structure of the heart chambers and the function of the heart valves. It also allows measurement of the blood pressure within the heart vessels (for pulmonary hypertension). The decision to perform a right heart catheterisation largely relies on the level of suspicion of pulmonary hypertension based on the echocardiogram.

Right Heart Catheterisation: This test is the gold standard diagnostic test for pulmonary hypertension. It uses a probe to measure the pressures in the heart and in the nearby blood vessels.

Other factors suggestive of pulmonary hypertension are:

• Significant reduction of gas transfer values in lung function tests
• Oxygen desaturation during a 6-minute walking test
• Significantly elevated BNP or NT-proBNP values
• Dilated pulmonary arteries on chest CT scan

Treatment For Pulmonary Hypertension

Timely diagnosis and treatment with medication is important for a favourable prognosis. It is very important to identify the actual cause of sarcoidosis associated pulmonary hypertension since this can be multifactorial. Treatment decisions are associated with the underlying cause and may include sarcoidosis specific treatment, heart failure treatment or even anti-coagulation.

Pulmonary hypertension specific medications can reduce symptoms and improve the pressures in the blood vessels.

You may be prescribed:

• Diuretics
• Anticoagulation (blood thinners)
• Endothelin antagonists such as bosentan, ambrisentan and macitentan
• Phosphodiesterase 5 inhibitors such as sildenafil and tadalafil
• Prostaglandins such as epoprostenol, iloprost and treprostinil
• Soluble guanylate cyclase stimulators such as riociguat
• Calcium channel blockers such as nifedipine, diltiazem, nicardipine and amlodipine

Lung and heart transplant may be considered. This is very rare.

Page last updated: October 2022. Next review: October 2023.