Саркоїдоз серця

Most patients with cardiac sarcoidosis are asymptomatic, but the associated bradyarrhythmias and tachyarrhythmias may cause palpitations, syncope, and sometimes cardiac arrest or sudden death.

A significant number of deaths resulting from systemic sarcoidosis are due to sudden cardiac death, including in many patients who have had no previous indication of cardiac involvement.

Cardiomyopathy may cause any heart failure symptom, including exertional dyspnea, fatigue, and peripheral edema.

In most patients, disease manifests between the ages of 25 to 60 years.

• Clinical suspicion

• ECG, echocardiography, and sometimes cardiac MRI with late gadolinium enhancement and/or fluorodeoxyglucose (FDG)-positron emission tomography (PET) scan

• Biopsy of noncardiac tissue that appears affected by systemic sarcoidosis

• Rarely cardiac biopsy

About 35% of the patients with cardiac sarcoidosis are already known to have systemic sarcoidosis or have clinical evidence of extracardiac sarcoidosis at presentation (1). Patients with known sarcoidosis and no cardiac symptoms should typically have periodic ECGs and echocardiography to screen for cardiac involvement. If cardiac symptoms, signs, or test abnormalities are present, cardiac MRI with gadolinium should also be done. Ambulatory ECG monitoring should be done if symptoms suggest a rhythm or conduction disturbance. An FDG-PET scan provides additional information regarding active inflammation and is usually also done.

In patients not yet diagnosed with systemic sarcoidosis, diagnosis of isolated cardiac sarcoidosis is frequently difficult. Cardiac sarcoidosis should be suspected in young patients with heart block, ventricular tachyarrhythmias, and/or heart failure who have no obvious cause. All such patients should have ECG and echocardiography. Patients with an unexplained cardiomyopathy should also have cardiac MRI.

When findings from these examinations suggest cardiac sarcoidosis or when there is a high suspicion thereof (eg, in young patients with unexplained AV block), further testing for cardiac sarcoidosis (ambulatory ECG monitoring, FDG-PET scanning) and testing for extracardiac sarcoidosis, (chest x-ray, chest CT, whole body FDG-PET scan) is needed. With extensive investigation, > 80% of patients with apparent isolated cardiac sarcoidosis are found to also have extracardiac sarcoidosis.

An international consensus document (2) indicated that the diagnosis of cardiac sarcoidosis requires a cardiac biopsy showing non-caseating granuloma without alternative explanation or an extracardiac tissue biopsy showing non-caseating granuloma without alternative explanation plus ≥ 1 of the following without alternative explanation:

• Corticosteroid-responsive cardiomyopathy or heart block

• Unexplained reduced left ventricular ejection fraction < 40%

• Unexplained spontaneous or induced ventricular tachycardia

• Mobitz type II second-degree AV block or third-degree AV block

• Cardiac PET scan showing patchy uptake

• Cardiac MRI showing late gadolinium enhancement

• Positive gallium uptake on a nuclear scan

Most commonly, the diagnosis is established by extracardiac biopsy in conjunction with suggestive cardiac abnormalities on noninvasive testing. Cardiac biopsy has low sensitivity because the disease process is patchy and pathological tissue may not be sampled. However, sensitivity of cardiac biopsy is improved if it is guided by advanced cardiac imaging techniques or by targeting areas of low voltage.

Similar, but not identical, criteria for the diagnosis of cardiac sarcoidosis have been published by the World Association of Sarcoidosis and Other Granulomatous Disorders (WASOG) (3) and the Japanese Circulation Society (JCS) (4).

• Corticosteroids

• Sometimes other immunosuppressive medications

• Sometimes permanent pacemaker and/or implantable cardioverter-defibrillator (ICD)

• Sometimes antiarrhythmic medications (avoiding class I medications)

• Sometimes transcatheter ablation

• Heart failure therapy (including transplantation) as required

Standard treatments for sarcoidosis itself are given, including corticosteroids and sometimes other immunosuppressants (eg, methotrexate). Tumor necrosis factor alpha inhibitors may be used for refractory cases. These modalities often also ameliorate cardiac abnormalities and should be optimized (1).

Cardiac treatment is focused on treatment and prevention of arrhythmias. Recommendations for treatment of bradyarrhythmias or tachyarrhythmias follow those for other arrhythmogenic cardiomyopathies. In cardiac sarcoidosis specifically, a pacemaker is recommended (class of recommendation IIa) for qualifying AV block even if the AV block reverses spontaneously (2).

When a permanent pacemaker is indicated (see table Indications for Permanent Pacemakers), an ICD is preferred (class IIa recommendation). The Heart Rhythm Society cardiac sarcoid consensus document recommends an ICD for patients with prior sustained VT, resuscitated cardiac arrest, or left ventricular ejection fraction of ≤ 35% despite optimal medical therapy (including a period of immunosuppression in patients with active inflammation) (each a class I recommendation)(2) (see table Indications for an ICD). The Heart Rhythm Society cardiac sarcoid consensus document also suggests an ICD can be useful (class IIa recommendation) for patients with cardiac sarcoidosis with unexplained syncope or near-syncope thought to be arrhythmic in etiology and for those with inducible sustained VT/VF at a programmed stimulation electrophysiologic study (each a class IIa recommendation) (2). The document further suggests that an ICD may be considered (class IIb recommendation) in patients with cardiac sarcoidosis with a left ventricular ejection fraction in the 35% to 49% range and/or a right ventricular ejection fraction < 40% despite optimal medical therapy for heart failure and use of immunosuppressants in patients with active inflammation (2). Similar, but not identical, recommendations for ICD therapy have been proposed by the Japanese Circulation Society (3), the American Heart Association/American College of Cardiology/Heart Rhythm Society (4), and the European Society of Cardiology (5). Because ventricular late gadolinium enhancement (LGE) on cardiac MRI (a marker of ventricular scarring) predicts life-threatening ventricular arrhythmias, ICD placement is recommended (class IIa recommendations) for patients with significant LGE despite an LVEF > 35% (4, 5).

Antiarrhythmic medications such as amiodarone and sotalol may be given as necessary to control frequently recurrent ventricular tachycardias and/or other tachyarrhythmias. If medications (and adequate anti-inflammatory therapy) do not control VT, electrophysiologic studies may be done to identify the origin of the arrhythmia (often a reentrant site) that can then be treated using transcatheter ablation.

Heart failure therapy typically includes a beta-blocker (watching for the possibility of worsening AV conduction), an angiotensin-converting enzyme inhibitor or an angiotensin II receptor blocker, and a mineralocorticoid receptor antagonist. Pharmacological treatments for dilated cardiomyopathy, including angiotensin receptor/neprilysin inhibitors and sodium-glucose cotransporter 2 inhibitors, have been less well studied in patients with cardiac sarcoidosis. The frequent coexistence of left bundle branch block in patients with sarcoidosis-related dilated cardiomyopathy makes cardiac resynchronization therapy attractive. Heart transplantation may be considered.

• About 25% of patients with systemic sarcoidosis have cardiac involvement, but only about 5% have cardiac symptoms.

• Cardiac involvement causes a disproportionate percentage of deaths in patients with sarcoidosis.

• Diagnosis requires a combination of clinical, electrocardiographic, and imaging findings; cardiac biopsy can be diagnostic but is not usually done.

• Cardiac manifestations often require a pacemaker/implantable cardioverter-defibrillator (ICD) and sometimes antiarrhythmic medications.

• Sarcoidosis itself is treated with corticosteroids and sometimes other immunosuppressants.

The following English-language resource may be useful. Please note that THE MANUAL is not responsible for the content of this resource.

1. Malhi JK, Ibecheozor C, Chrispin J, et al: Diagnostic and management strategies in cardiac sarcoidosis. Int J Cardiol 403:131853, 2024. doi: 10.1016/j.ijcard.2024.131853

2. Ribeiro Neto ML, Jellis CL, Cremer PC, et al: Cardiac Sarcoidosis. Clin Chest Med 45(1):105–118, 2024. doi: 10.1016/j.ccm.2023.08.006.