Raising the Alarm

Background

Cardiac abnormalities are often the first or only sign of sarcoidosis. Current guidelines recommend evaluating for cardiac sarcoidosis (CS) in patients below 60 years with unexplained complete heart block (CHB).

Objectives

The aim of the study was to assess the proportion of patients with unexplained CHB who receive guideline-recommended testing for CS and to compare subsequent diagnosis rates with expected prevalence.

Methods

We conducted a retrospective cohort study using TriNetX data, identifying patients aged 18 to 60 years with unexplained CHB requiring device placement over the past 5 years. We assessed the use of cardiac diagnostic tests—cardiac magnetic resonance imaging, positron emission tomography, chest computed tomography, and myocardial biopsy—and tracked CS diagnoses over 5 years.

Results

Among 1,279 patients meeting criteria across 55 health care organizations, 75% were treated at academic centers. The mean age was 48 ± 11 years; 53% were male, and 73% were White. Over a median follow-up of 724 days (Q1-Q3: 0-1,117), advanced cardiac testing was performed in 256 patients (20.0%; 95% CI: 17.8%-22.2%). Specific test utilization included cardiac magnetic resonance imaging in 131 patients (10.2%; 95% CI: 8.6%-11.9%), chest computed tomography in 141 (11.0%; 95% CI: 9.3%-12.7%), cardiac positron emission tomography in ≤10 (0.7%; 95% CI: 0.3%-1.3%), and myocardial biopsy in ≤10 (0.7%; 95% CI: 0.3%-1.3%). Fewer than 10 patients (<1%; 95% CI: 0.3%-1.3%) were diagnosed with CS, far below the expected prevalence of 19% to 34%.

Conclusions

Despite guideline recommendations, diagnostic testing for CS in younger patients with unexplained CHB remains low. This gap likely contributes to significant underdiagnosis and highlights the need for improved adherence to evaluation protocols.