Goldar, Sifuentes spot evaluation gap in cardiac care

When a young patient experiences unexplained complete heart block (CHB), cardiologists typically prioritize acute concerns through interventions like pacemaker implantation. However, identifying the condition’s underlying cause, such as cardiac sarcoidosis (CS), is crucial, as it can significantly impact treatment strategy, long-term management, and even the type of device selected. In a retrospective study featured in JACC: Advances, University of Iowa Health Care Cardiovascular Disease Fellows Ghazaleh Goldar, MD, and Aaron Sifuentes, MD, identified an alarming national trend: providers infrequently test younger patients with CHB for cardiac sarcoidosis, despite American Heart Association guidelines recommending CS screening in such cases. This paper is the first large-scale study spanning multiple healthcare organizations to examine providers’ adherence to CS evaluation guidelines for young CHB patients.

Cardiac sarcoidosis consists of granulomatous formation in the heart tissue, disrupting healthy functioning. Sarcoidosis typically develops in middle-aged adults, and its manifestations range from heart rhythm abnormalities to heart failure and sudden cardiac death.

With an elevated risk of serious or fatal cardiac dysfunction, a CS diagnosis necessitates an implantable cardioverter defibrillator over a standard pacemaker typically placed in CHB patients. Early diagnosis in this young population is crucial, as timely initiation of immunosuppressive therapy and appropriate device selection can reduce the risk of life-threatening arrhythmias and prevent disease progression.

“As the title of our paper suggests, our goal was to raise awareness about the underdiagnosis of cardiac sarcoidosis. By bringing attention to this gap in care, we hope to prompt more consistent adherence to guideline-recommended screening, ensuring that diagnostic evaluation becomes a routine part of management in this population of patients,” Goldar said. “Our findings also highlight the importance of an interdisciplinary approach, engaging subspecialist colleagues to ensure comprehensive evaluation and optimal and timely treatment for these patients.”

Using TriNetX data, Goldar analyzed a subset of 4,222 patients aged 18 to 60 years who were diagnosed with unexplained CHB between 2020 and 2025. Of these patients, 1,279 met the study’s inclusion criteria: diagnosis of a complete atrioventricular block requiring the placement of an implantable device within a month of diagnosis. The study excluded CHB patients whose diagnosis originated from a distinct medical event or co-morbid condition.

Goldar and Sifuentes’s analysis revealed that only 20% of the study cohort underwent CS screening after diagnosis of unexplained CHB. About 1% of those tested received a CS diagnosis, far below the expected prevalence of 19% to 34%. Goldar and Sifuentes suggest that gaps in the evaluation process are partially responsible for the low incidence rate among the cohort’s CS-screened patients.

Sifuentes outlined several factors that may influence institutional adherence to CS screening guidelines. Clinical demands, referral delays, and the urgency of managing CHB often lead to rapid pacemaker implantation, unintentionally postponing or limiting the opportunity for timely diagnostic evaluation. After device placement, patients frequently experience restricted arm mobility and may be temporarily ineligible for advanced imaging. Myocardial biopsy remains an option, though clinicians typically reserve the procedure for select cases due to its invasive nature.

Sifuentes added that limited access to specialized centers, multidisciplinary teams, and advanced imaging modalities, particularly in non-academic settings, further contributes to CS underdiagnosis. Still, the trend of low adherence to CS screening guidelines spans both academic and non-academic institutions, underscoring the need for broader awareness and systemic change.

Goldar said the cardiovascular field needs to expand its research on the prevalence, onset, and screening of cardiac sarcoidosis in different cardiac conditions. She awaits publication from JACC: Advances on another paper examining the underdiagnosis of CS in patients with unexplained ventricular arrhythmias. In the meantime, Goldar and Sifuentes have no trouble raising the alarm, especially since CS testing can be the difference between a fatal cardiac event and a successful treatment intervention.

The pair also credit the contributions of Cardiovascular Medicine faculty members Peter D. Farjo, MD, MS, and Paari Dominic, MBBS, MPH, senior authors on the journal article. “We are deeply grateful to Drs. Dominic and Farjo for their invaluable mentorship and unwavering support throughout this project. Their guidance, insight, and encouragement were instrumental at every stage, and this work would not have been possible without them.”