Reduced 18F-FDG uptake in the basal interventricular septum as a predictor of fatal ventricular arrhythmic events in patients with cardiac sarcoidosis.

BACKGROUND

Patients with cardiac sarcoidosis (CS) are at an increased risk of fatal ventricular arrhythmic events (FVAE). However, the predictive value of 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) in assessing the risk of FVAE in patients with CS remains uncertain.

METHODS

We included data from 121 patients with CS (39 men and 82 women; mean age: 59.5 years) who underwent FDG-PET imaging between March 2008 and November 2020, with follow-ups completed in July 2023. Of these, 82 patients had available cardiac magnetic resonance imaging data, including late gadolinium enhancement (LGE). FDG-PET images were analysed using a polar-map model to determine the regional mean percentage uptake relative to the maximal cardiac 18F-FDG uptake in each of the 17 segments defined by the American Heart Association.

RESULTS

Patients experiencing FVAE after FDG-PET (n = 43) showed lower percent uptake in the basal inferoseptal segment compared to those who did not (n = 78) (41.8 ± 15.2 % vs. 54.4 ± 13.8 %, P < 0.001). Patients with a basal inferoseptal percent uptake below the median had a lower FVAE-free survival rate than those with a higher percent uptake (58.1 % vs. 78 % at 5 years, P = 0.007), which was consistent in patients with LGE in the same regions with reduced 18F-FDG uptake. A Cox hazard model indicated that the FVAE risk decreased with a hazard ratio of 0.862 (95 % CI 0.770-0.964) for every 5 % increase in basal inferoseptal percent uptake (P = 0.009).

CONCLUSION

Reduced 18F-FDG uptake in the basal interventricular septum, including the inferoseptal segment, may be a valuable predictor of future FVAE in patients with CS.