Sarcoidosis Patients More Likely to Develop Heart Rhythm Disorders, Large Retrospective Study Finds

Patients with sarcoidosis are more likely to have heart rhythm disorders, specifically ventricular tachycardia, and experience cardiac arrest, a review of a large sample of inpatients in the United States found.

Greater rates of heart complications in sarcoidosis patients may worsen the disease burden and the mortality associated with the condition, researchers say.

The study, “Cardiac sarcoidosis and ventricular arrhythmias. A rare association of a rare disease. A retrospective cohort study from the National Inpatient Sample and current evidence for management,” was published in the Cardiology Journal.

Sarcoidosis is a disease marked by the formation of inflammatory cell clumps, or granulomas, in different tissues and organs, which can disrupt their proper function. The disease may manifest in several subtypes, depending on the organs it affects.

Cardiac sarcoidosis refers to patients whose granulomas occur in the heart, often in the heart’s muscle, affecting its electrical conduction, causing irregular heartbeats or arrhythmias. The condition is reported to affect a wide range of patients with systemic sarcoidosis, from 3.7 to 54.9%.

Cardiac sarcoidosis can be life-threatening, and has been associated with an increased rate of ventricular arrhythmias (irregular rhythms in the lower pumping chambers of the heart, called ventricles), heart failure, and higher mortality.

However, little epidemiological data is available regarding the disease and its association with heart disorders, in specific ventricular tachycardia (when the heart’s ventricles beat faster than normal).

A team of researchers set out to address this problem by comparing the prevalence of such heart disorders in a large sample of sarcoidosis patients and those without the disease. The team hypothesized that cardiac sarcoidosis could predict the development of ventricular tachycardia.

Researchers retrospectively reviewed the medical records of patients from the National Inpatient Sample (NIS) between 2012-2014. NIS is the largest publicly available healthcare database of patients who have been hospitalized in the United States.

The study included 46,289 subjects with a diagnosis of sarcoidosis, and 17,967,589 patients who did not have the condition.

Results showed that both ventricular tachycardia and ventricular fibrillation (rapid, irregular beats) were more prevalent among patients with sarcoidosis compared to those without it  — 2.29% versus 1.22%, and 0.25% versus 0.21%, respectively.

When these two types of ventricular arrhythmias happen, the heart may not be able to pump enough blood to the body and lungs because the chambers are beating too fast or quivering.

Sarcoidosis patients also had a higher prevalence of cardiac arrest (0.72% versus 0.6%), a sudden stop in the heart’s beating due to electrical system malfunctions, which can often be fatal. These patients were also two times more likely to have congestive heart failure.

Hypertension (65.2% versus 51.74%), chronic kidney disease (21.09% versus 14.02%), and diabetes (31.6% versus 21.25%) were also more common in the sarcoidosis group.

“The present study showed that sarcoidosis was associated with increased rates of ventricular tachyarrhythmia, which can affect the overall disease morbidity and mortality,” the researchers wrote.

According to the team, the results suggest that cardiac sarcoidosis may be an independent risk factor for ventricular tachycardia.

However, the management of arrhythmias in this condition is difficult, and effective control of ventricular tachycardia is often not achievable with a single therapy, the researchers noted.

Steroids remain central in the management of cardiac sarcoidosis but “recurrent VT [ventricular tachycardia] may increase with steroid therapy as active granulomas are replaced by fibrosis, a substrate for re-entrant arrhythmias.” Therefore, the team suggested that immunosuppressive therapies be used in cases of resistant arrhythmias or as a steroid-sparing strategy.