Clinical significance of quantitative assessment of right ventricular glucose metabolism in patients with heart failure with reduced ejection fraction

Purpose Dynamic F-18-fluorodeoxyglucose (FDG) PET can be used to quantitatively assess the rate of myocardial glucose uptake (MRGlu). The aim of this study was to evaluate the clinical significance and prognostic value of right ventricular (RV) MRGlu in patients with coronary artery disease and heart failure with reduced ejection fraction. Methods Patients with left ventricular ejection fraction (LVEF) <= 40% were consecutively enrolled for FDG PET between November 2012 and May 2017. Global LV and RV MRGlu (mu mol/min/100 g) were analyzed. Outcome events were independently assessed using electronic medical records to determine hospitalization for revascularization, new-onset ischemic events, heart failure, cardiovascular, and all-cause death. Differences between LV and RV MRGlu and associations with clinical characteristics and echocardiographic data were evaluated. Associations among FDG PET findings and outcomes were analyzed using Kaplan-Meier survival analysis. Results Seventy-five patients (mean age 62.2 +/- 12.7 years, male 85.3%, LVEF 19.3 +/- 8.6%) were included for analysis. The mean glucose utilization ratio of RV-to-LV (RV/LV MRGlu) was 89.5 +/- 264.9% (r = 0.77, p < 0.001). Positive correlations between RV MRGlu and maximal tricuspid regurgitation peak gradient (r = 0.28, p = 0.033) and peak tricuspid regurgitation jet velocity (r = 0.29, p = 0.021) were noted. LVEF was positively correlated with LV MRGlu (r = 0.27, p = 0.018), but negatively correlated with end-diastolic volume (r = - 0.37, p = 0.001), end-systolic volume (r = - 0.54, p < 0.001), and RV/LV MRGlu (r = - 0.40, p < 0.001). However, RV MRGlu was not well correlated with LVEF. Forty-three patients received revascularization procedures after FDG PET, and 13 patients died in a mean follow-up period of 496 +/- 453 days (1-1788 days), including nine cardiovascular deaths. Higher RV and LV MRGlu values, LVEF <= 16% and LV end-diastolic volume >= 209 ml of gated-PET were associated with poor overall survival and cardiac outcomes. Conclusions In patients with coronary artery disease and ischemic cardiomyopathy, RV glucose utilization was positively correlated with RV pressure overload, but not LVEF. Global LV and RV MRGlu, LVEF, and LV end-diastolic volume showed significant prognostic value.