# Diagnostic delay and phenotypic differences in cardiac sarcoidosis: a descriptive study of diagnostic and follow-up clinical data

## TL;DR

This study explores how delayed diagnosis affects outcomes in cardiac sarcoidosis, finding that de novo cases have more severe symptoms and worse heart function.

## Contribution

The study identifies associations between diagnostic delay, disease presentation, and clinical outcomes in cardiac sarcoidosis patients.

## Key findings

- Diagnostic delay was linked to higher likelihood of cardiac resynchronisation therapy defibrillator implantation.
- De novo cardiac sarcoidosis patients had more severe symptoms and reduced heart function compared to those with prior extracardiac sarcoidosis.
- Reduced left ventricular ejection fraction was more common in de novo patients with diagnostic delay.

## Abstract

Worse prognosis in cardiac sarcoidosis (CS) is likely associated with diagnostic delay and cardiac involvement as first sarcoidosis (de novo) presentation, but data are limited.

We retrospectively investigated 95 patients with CS diagnosed 2003–2024. Using electronic health records, the date of first CS symptoms/signs, immunosuppressant therapy and follow-up data including left ventricular ejection fraction (LVEF), biomarkers and cardiac device therapy were extracted. Median time from first symptoms/signs to CS diagnosis (9 months) was used to define delayed diagnosis.

Implantation of cardiac resynchronisation therapy defibrillator was more likely in patients with diagnostic delay (p=0.01). No difference was observed in time to diagnosis between patients with de novo CS (n=49) and those with prior extracardiac sarcoidosis (ECS) (n=46). Severe symptoms at disease onset were more common in de novo CS. At a median of 46 months from diagnosis, de novo patients more often had reduced LVEF (p=0.006) and an implantable cardioverter defibrillator (p<0.05) than those with prior ECS despite receiving more immunosuppressant therapy. De novo patients with diagnostic delay more often had reduced LVEF at CS presentation.

Symptom presentation is likely associated with diagnostic delay, but the disease presentation and course seem more severe in de novo CS and may not be altered by immunosuppressants, or demand more aggressive therapy.