In rare cases, cardiac sarcoidosis (CS) can lead to heart failure — although this risk is not often considered by physicians unaccustomed to seeing it. Sarcoidosis patients with cardiac involvement, however, have an overall worse prognosis than those without it, according to a study published in the journal Heart Failure Reviews.
Drawing on a case study of an African-American treated for what turned out to be CS, researchers used their article, “A complete heart block in a young male: a case report and review of literature of cardiac sarcoidosis,” to present an overview on what is known about CS diagnosis, heart involvement and symptoms, and treatment. Its authors also argued for greater research into this condition to better understand and treat it.
Sarcoidosis, characterized by an abnormal accumulation of inflammatory cells in organs that form structures called granulomas, is 10 to 17 times more prevalent among blacks than whites in the U.S. But the majority of the sarcoidosis patients with heart involvement — an estimated 95% of them — do not present any symptoms, or only atypical symptoms.
In the study, a 42-year-old African-American man came to the hospital for evaluation of multiple lung nodules and increased lymph nodes in the chest. He had a history of heart disease, hypertension, and chronic kidney disease.
The patient’s vital signs were all normal and a cardiac exam did not show any alterations. But within two days of admission, he developed a rash stretching from the forehead to the abdominal area.
An electrocardiogram (ECG) exam found a complete heart block, and a cardioverter defibrillator (ICD) was implanted to restore normal cardiac rhythm. The ECG also showed severe heart alterations within the ventricles structure, and a biopsy of the left lung revealed multiple granulomas consistent with sarcoidosis.
Based on the lung evidence of sarcoidosis and the ECG findings, the patient was diagnosed with CS. But with a lack of treatment guidelines, and knowing the patient already had an ICD, physicians decided to simply place him on steroids. They found this choice kept him asymptomatic and in a paced rhythm.
As demonstrated in the case study, CS can involve different elements of the cardiac system, such as the myocardium, pericardium, or heart valves. Its clinical manifestations can be equally diverse, ranging from asymptomatic to severe arrhythmias, and include ventricular tachycardia and complete heart block.
Due to the absence of clear guidelines or specific clinical characterization, CS diagnosis is difficult. Many cases are misdiagnosed or only belatedly diagnosed and treated.
“We recommend that all patients with sarcoidosis be screened using a detailed history, physical exam, ECG, and echocardiography,” the researchers wrote, suggesting this as a way of detecting CS early.
“It is difficult to make a diagnosis strictly based on clinical grounds. However, in the setting of extracardiac sarcoidosis and patients presenting with advanced heart block or ventricular arrhythmia, direct cardiac involvement should be suspected,” they said, adding, “The definitive diagnosis of cardiac sarcoidosis can be made from endomyocardial biopsy.”
CS management can also be difficult. No clinical trials have been done to determine best therapeutic approaches, so recommended treatments are based on observational and retrospective trials. These approaches are:
- Control of inflammation with steroid-based drugs. This is considered the standard therapy for CS
- Immunosuppressive drugs, methotrexate, and antimalarial drugs are used in patients who cannot tolerate steroids
- For those with severe CS, pacemakers, such as an ICD, should be considered to correct heart arrhythmias
- As a last resort, cardiac surgery to correct heart defects, or a heart transplant, can be considered.
“The rarity combined with underdiagnosis of CS continues to remain a hurdle in conduction of large prospective, randomized control trial but should be encouraged,” the authors concluded.
Sarcoidosis is known to mainly affect the lung and lymph nodes, but it is actually a multiple organ disease, and can affect the skin, eyes, kidneys, and central nervous system, as well as the heart.