RT Journal Article
SR Electronic
T1 Differential Effects of Nonselective Versus Selective β-Blockers on Cardiac Sympathetic Activity and Hemostasis in Patients with Heart Failure
JF Journal of Nuclear Medicine
JO J Nucl Med
FD Society of Nuclear Medicine
SP 1733
OP 1739
DO 10.2967/jnumed.113.120477
VO 54
IS 10
A1 Olav R. de Peuter
A1 Hein J. Verberne
A1 Wouter E. Kok
A1 Bas van den Bogaard
A1 Marianna C. Schaap
A1 Rienk Nieuwland
A1 Joost C.M. Meijers
A1 G. Aernout Somsen
A1 Ad Bakx
A1 Pieter W. Kamphuisen
YR 2013
UL http://jnm.snmjournals.org/content/54/10/1733.abstract
AB Carvedilol, a nonselective β-blocker, may be more effective than the selective β-blocker metoprolol in reducing the risk of thromboembolic events in heart failure. The aim of this study was, first, to assess whether there is a differential response in cardiac sympathetic activity by 123I-meta-iodobenzylguanidine (123I-MIBG) imaging when either β-blocker is used. Second, we assessed whether that response correlates with levels of various serum factors that serve as markers for coagulability. Methods: In this prospective, randomized, open-label crossover study with masked outcome assessments, stable heart failure patients (left ventricular ejection fraction < 40%) homozygous for the Arg16/Gln27 (n = 13) or Gly16/Glu27 haplotype (n = 8) of the β2-receptor were randomized to equipotent dosages of carvedilol or metoprolol for two 6-wk periods. Primary outcome was sympathetic activity as measured by 123I-MIBG myocardial washout. Secondary outcomes included markers of hemostasis. Results: 123I-MIBG cardiac washout was lower during carvedilol than metoprolol treatment (12.9% ± 3.9% vs. 22.1% ± 2.8%, respectively, P = 0.003), irrespective of β2-adrenergic receptor haplotype. In addition, treatment with carvedilol resulted in a lower von Willebrand factor than did metoprolol (149% ± 13% vs. 157% ± 13%, respectively, P = 0.01), irrespective of β2-adrenergic receptor haplotype. Conclusion: Compared with metoprolol, carvedilol resulted in greater reduction of sympathetic activity after 6 wk of treatment and lower von Willebrand factor concentrations in both Arg16/Gln27 and Gly16/Glu27 individuals. Therefore, carvedilol may reduce the risk of thromboembolic events in patients with heart failure, irrespective of β2-receptor haplotype status.