Specific locations of myocardial inflammation and fibrosis are associated with higher risk of events in cardiac sarcoidosis.

Abstract

Background: ¹⁸F-Fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography (PET)/magnetic resonance (MR) can identify inflammation and fibrosis, which are high-risk features in cardiac sarcoidosis.

Objective: The purpose of this study was to evaluate whether the involvement of certain myocardial segments is associated with higher risk compared to others.

Methods: One hundred twenty-four patients with suspected clinical sarcoidosis underwent ¹⁸F-FDG-PET/MR. Late gadolinium enhancement (LGE) and focal ¹⁸F-FDG uptake were evaluated globally and in the 16 myocardial segments. Presence of LGE was defined when the percentage of LGE exceeded 5.7% globally (relative to myocardial volume) and in each myocardial segment. Patients were followed up for 5.5 years. Events were defined as ventricular arrhythmia (VA) (including sustained ventricular tachycardia, ventricular fibrillation, and appropriate implantable cardioverter-defibrillator discharge), heart failure hospitalization, or all-cause death.

Results: Mean age was 57.1 ± 8.9 years, and 39.5% were female. Twenty-two patients (17.6%) had an event during follow-up, and 9 (7.2%) presented with VA. LGE and ¹⁸F-FDG uptake were more frequent in patients with than without events (36.4% vs 7.8%, P = .001). Presence of LGE and ¹⁸F-FDG in the basal anterior segment were independent predictors for events after adjustment for left ventricular ejection fraction and relative enhanced volume (LGE: odds ratio [1.2-92.4], P = .034;¹⁸F-FDG: odds ratio 5.5 [1.1-27.5], P = .038). LGE presence in basal to mid-anterior, mid-anteroseptal, and basal to mid-inferoseptal segments was an independent predictor of VA. Presence of ¹⁸F-FDG in basal to mid-anterior, mid-inferoseptal and mid-inferior segments was an independent predictor of VA.

Conclusion: Involvement of specific myocardial segments, particularly basal to mid-anterior and mid-septal segments, is associated with higher rates of events in patients with suspected cardiac sarcoidosis.