A Combination of Screening Tools May Help Rule Out Silent Cardiac Sarcoidosis

A study reports the prevalence of this condition and examines several cardiac assessments.

Recent research found that almost one quarter of people with sarcoidosis have clinically silent cardiac involvement, with no typical cardiac symptoms.

According to the study findings, readily available cardiac screening tools, when used together, may help rule out this hidden manifestation of the disease and avoid the need for expensive and unnecessary MRI scans.

The study, “Screening Tools for Detecting Clinically Silent Cardiac Sarcoidosis,” was published in Respiratory Medicine.

In sarcoidosis, clusters of inflammatory cells called granulomas build up in the body’s organs. When they develop in the heart, this is called cardiac sarcoidosis (CS).

Around 5% of people with sarcoidosis have symptomatic or clinically apparent cardiac sarcoidosis, characterised by changes in heart rhythm or heart failure. By contrast, approximately 20–25% are thought to have clinically silent cardiac involvement, without such obvious symptoms.

Even without clear symptoms, cardiac sarcoidosis may still be associated with an increased risk of adverse outcomes. The researchers noted that it has been identified as a leading cause of death among Japanese people with sarcoidosis.

Detecting the condition is therefore critical. Cardiac MRI is the gold standard for detection, but this approach is expensive and may not be readily available. “A simpler and more accessible screening algorithm is warranted,” the researchers wrote.

Other routine tests used to assess the structure and function of the heart include an electrocardiogram (ECG), Holter monitoring, a signal-averaged electrocardiogram (SAECG) and a transthoracic echocardiogram (TTE), together with a clinical history of cardiac symptoms.

Study findings

In their study, the researchers examined the possible usefulness of these commonly available screening tools for diagnosing silent cardiac sarcoidosis in 129 people with established extracardiac sarcoidosis—that is, sarcoidosis affecting organs outside the heart—with no evidence of clinically apparent cardiac sarcoidosis.

The participants were recruited through the multicentre CHASM-CS patient registry (NCT01477359), sponsored by the University of Ottawa Heart Institute in Canada.

Using gold-standard cardiac magnetic resonance imaging, 29 participants (22.5%) were found to have clinically silent cardiac sarcoidosis; 19 (14.7%) were classified as having substantial cardiac involvement.

Most participants with cardiac sarcoidosis—25 of 29—were men, resulting in a significant sex difference. A pre-existing diagnosis of hypertension (high blood pressure) was also significantly more common among people with silent cardiac sarcoidosis.

The symptom history showed that 15 of all 129 participants had cardiac symptoms. Cardiac testing identified abnormalities in 36 people (27.9%) on ECG, 10 (7.8%) on TTE, 26 (20.2%) on Holter monitoring and 51 (53.1%) on SAECG.

Overall, each individual test had relatively low diagnostic accuracy for cardiac sarcoidosis. However, combining selected screening tools improved their accuracy.

For example, the most effective screening approach combined normal Holter and SAECG results and correctly identified 45% of participants without cardiac involvement on MRI.

According to the researchers, screening tools generally had greater accuracy for detecting cardiac sarcoidosis with substantial cardiac involvement.

Overall, the findings show that these common screening tools, when used together, “may be particularly useful for avoiding the need for additional advanced cardiac imaging,” the researchers wrote.

Nevertheless, the results do not mean that cardiac MRI should be eliminated altogether, the scientists stressed.

“Feasible screening for CS [cardiac sarcoidosis] should not focus on finding alternative tools to completely avoid CMR [cardiac MRI], but rather on ruling out true-negative cases that do not need additional expensive imaging,” they wrote.

Future studies should aim to confirm these findings in larger and more diverse patient populations, the scientists noted. The team also indicated that a cost-effectiveness analysis is warranted for routine screening for cardiac sarcoidosis.

Source: https://sarcoidosisnews.com/news/combo-screening-tools-may-help-rule-out-silent-cardiac-sarcoidosis/