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

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.