Relationship between the standardized uptake value (SUV) and left ventricular ejection fraction (LVEF) in patients with cardiac sarcoidosis (CS)

Objectives The purpose of our study was to determine the effect of Anti-inflammatory therapy (AIT) on FDG SUV and LVEF and determine the relationship of the change in LVEF and the change in SUV in a cohort of patients with CS.

Methods 14 patients with CS were recruited. Fasting whole body and cardiac FDG-PET was performed. LV SUV (mean and maximum) was determined. LVEF was evaluated by gated N-13 ammonia or Rb-82 PET at baseline and follow-up. The changes of the LVEF classified into 3 categories; improved: absolute LVEF increased >/= 10%; no change: LVEF change < 10%; deteriorated: LVEF decreased >/=10%.

Results All 14 patients showed focal FDG uptake in the LV at baseline. 12 patients had AIT (treatment group) and 2 patients were observed without AIT. In the treatment group, the max SUVs in the LV after AIT were significantly decreased compared to those at the baseline (8.40+/-2.70 vs 3.40+/-1.65; p=0.0002) (similar degree of change for overall mean SUVs) but EF did not change (44.3+/-17.0 vs 41.9+/-13.8; p=0.72). 8 out of 12 (67%) showed more than 50% reduction in SUVs at follow-up period: 2 had increased LVEF and 1 had reduced EF and 5 had no change. In the remaining 4 patients in the treatment group with less reduction in SUVs, 3 patients no change in LVEF, 1 patient showed deterioration of LVEF. In the 2 patients without AIT, 1 patient demonstrated more than 50% reduction in SUVs with improvement of LVEF, 1 patient showed no reduction in SUVs with no change in LVEF. There was no significant relationship between the change in max SUVs and change in EF (r2=0.04;p=0.48).

Conclusions In this small cohort, while AIT was associated with a significant reduction of FDG SUV with 8/12 patients having more than 50% reduction, there was not a significant effect on change in LVEF. Also 1/2 patients without AIT had a more than 50% reduction in SUV. Larger prospective studies are warranted.