Polymorphism of SLC6A2 gene does not influence outcome of myocardial (123)I-mIBG scintigraphy in patients with chronic heart failure

The NET, encoded by SLC6A2, is responsible for presynaptic NE-reuptake. (123)I-mIBG is clinically used to evaluate cardiac sympathetic function. However, it is unknown if polymorphism of SLC6A2 influences cardiac sympathetic activity as assessed with (123)I-mIBG. Therefore we studied the influence of SLC6A2 SNPs on myocardial (123)I-mIBG parameters in CHF. Forty-nine adults with stable CHF (age 66.5 ± 8.1 years, LVEF 22.3 ± 6.4) were enrolled. Fifteen minutes (early) and 4 hours (late) after administration of (123)I-mIBG planar images were acquired. The H/M ratio was calculated from the manually drawn ROI over the left ventricle and a fixed mediastinal ROI. Fourteen exons of the SLC6A2 gene were analyzed from whole blood samples. We found 6 different SLC6A2 SNPs, although none were functional. LVEF was the only independent predictor for early (adjusted R (2) = 0.063, p = 0.045) and late H/M ratio (adjusted R (2) = 0.116, p = 0.010). NT-proBNP was the only independent predictor for (123)I-mIBG WO (adjusted R (2) = 0.074, p = 0.032). SLC6A2 SNPs were not associated with any myocardial (123)I-mIBG-derived parameter. In this specific CHF population polymorphism of SLC6A2 gene was not associated with any (123)I-mIBG derived parameters