TY - JOUR T1 - Myocardial β-Adrenergic Receptor Density Assessed by <sup>11</sup>C-CGP12177 PET Predicts Improvement of Cardiac Function After Carvedilol Treatment in Patients with Idiopathic Dilated Cardiomyopathy JF - Journal of Nuclear Medicine JO - J Nucl Med SP - 220 LP - 225 DO - 10.2967/jnumed.108.056341 VL - 50 IS - 2 AU - Masanao Naya AU - Takahiro Tsukamoto AU - Koichi Morita AU - Chietsugu Katoh AU - Kenichi Nishijima AU - Hiroshi Komatsu AU - Satoshi Yamada AU - Yuji Kuge AU - Nagara Tamaki AU - Hiroyuki Tsutsui Y1 - 2009/02/01 UR - http://jnm.snmjournals.org/content/50/2/220.abstract N2 - We evaluated whether myocardial β-adrenergic receptor (β-AR) density, as determined by 11C-CGP12177 PET, could predict improvement of cardiac function by β-blocker carvedilol treatment in patients with idiopathic dilated cardiomyopathy (IDC). Methods: Ten patients with IDC (left ventricular ejection fraction [LVEF] &lt; 45%) were studied. Myocardial β-AR density was estimated using 11C-CGP12177 PET before treatment with carvedilol. Changes of LVEF in response to dobutamine infusion (ΔLVEF-dobutamine) were also measured by echocardiography. Changes of LVEF (ΔLVEF-carvedilol) were evaluated after 20 mo of carvedilol treatment. Results: Baseline myocardial β-AR density significantly correlated with ΔLVEF-carvedilol (r = −0.88, P &lt; 0.001). In contrast, ΔLVEF-dobutamine did not correlate with ΔLVEF-carvedilol (P = 0.65). Myocardial β-AR density was the significant multivariate independent predictor of ΔLVEF-carvedilol (β = −0.88, P &lt; 0.001) among univariate predictors, including functional class (r = 0.76, P &lt; 0.05), plasma norepinephrine (r = 0.85, P &lt; 0.01), LVEF (r = −0.64, P &lt; 0.05), and age as confounding factors. Furthermore, myocardial β-AR density was significantly correlated with plasma norepinephrine (r = −0.79, P &lt; 0.01) and LVEF (r = 0.70, P &lt; 0.05). Conclusion: Myocardial β-AR density is more tightly related to improvement of LVEF-carvedilol than is cardiac contractile reserve in patients with IDC. Patients with decreased myocardial β-AR have higher resting adrenergic drive, as reflected by plasma norepinephrine, and may receive greater benefit from being treated by antiadrenergic drugs. ER -