In dilated cardiomyopathy (DCM), there are limited data on right ventricular (RV) glucose metabolism assessed by [¹⁸F]fludeoxyglucose positron emission tomography (¹⁸F-FDG PET) imaging. We aimed to characterize RV glucose metabolism and investigate the prognostic significance of RV FDG uptake in DCM.

¹⁸F-FDG PET imaging and cardiac magnetic resonance imaging (MRI) were performed in 63 consecutive DCM patients within an interval of 3-7 days. There was a significant correlation between RVEF and RV FDG uptake whether corrected RV standard uptake value (cRVSUV) (r = −0.571, P < .001) or the relative RV FDG uptake determined as the ratio of RV to left ventricular (LV) corrected SUV (cR/L) (r = −0.405, P < .001) was used. During a median follow-up period of 804 days, 15 patients (23.8%) reached the primary endpoint of all-cause mortality or heart transplantation. On univariate Cox analysis, cRVSUV > 7.01 and cR/L > 0.795 were significantly associated with the overall survival (hazard ratio [HR] 5.415, 95% confidence interval [CI] 1.945-15.078, P < .001; HR 6.422, 95% CI 2.250-18.332, P < .001). Patients with increased RV FDG uptake had a worse outcome (cRVSUV > 7.01 vs cRVSUV ≤ 7.01, log-rank 13.085, P < .001; cR/L > 0.795 vs cR/L ≤ 0.795, log-rank 15.695, P < .001). On multivariate analysis, cR/L > 0.795 remained a significant independent predictor of the endpoint (HR 5.001, 95% CI 1.641-15.239, P = .004), while cRVSUV > 7.01 showed no significance (HR 2.611; 95% CI 0.797-8.558; P = .113).

Increased RV FDG uptake was associated with RV dysfunction and may be a prognostic predictor of all-cause mortality or heart transplantation in patients with DCM.