Effect of Nebivolol on MIBG Parameters and Exercise in Heart Failure with Normal Ejection Fraction.
BACKGROUND
More than 50% of the patients with heart failure have normal ejection fraction (HFNEF). Iodine-123 metaiodobenzylguanidine (123I-MIBG) scintigraphy and cardiopulmonary exercise test (CPET) are prognostic markers in HFNEF. Nebivolol is a beta-blocker with vasodilating properties.


OBJECTIVE
To evaluate the impact of nebivolol therapy on CPET and123I-MIBG scintigraphic parameters in patients with HFNEF.


METHODS
Twenty-five patients underwent 123I-MIBG scintigraphy to determine the washout rate and early and late heart-to-mediastinum ratios. During the CPET, we analyzed the systolic blood pressure (SBP) response, heart rate (HR) during effort and recovery (HRR), and oxygen uptake (VO2). After the initial evaluation, we divided our cohort into control and intervention groups. We then started nebivolol and repeated the tests after 3 months.


RESULTS
After treatment, the intervention group showed improvement in rest SBP (149 mmHg [143.5-171 mmHg] versus 135 mmHg [125-151 mmHg, p = 0.016]), rest HR (78 bpm [65.5-84 bpm] versus 64.5 bpm [57.5-75.5 bpm, p = 0.028]), peak SBP (235 mmHg [216.5-249 mmHg] versus 198 mmHg [191-220.5 mmHg], p = 0.001), peak HR (124.5 bpm [115-142 bpm] versus 115 bpm [103.7-124 bpm], p= 0.043), HRR on the 1st minute (6.5 bpm [4.75-12.75 bpm] versus 14.5 bpm [6.7-22 bpm], p = 0.025) and HRR on the 2nd minute (15.5 bpm [13-21.75 bpm] versus 23.5 bpm [16-31.7 bpm], p = 0.005), but no change in peak VO2 and 123I-MIBG scintigraphic parameters.


CONCLUSIONS
Despite a better control in SBP, HR during rest and exercise, and improvement in HRR, nebivolol failed to show a positive effect on peak VO2 and 123I-MIBG scintigraphic parameters. The lack of effect on adrenergic activity may be the cause of the lack of effect on functional capacity.
Universidade Federal Fluminense, Rio de Janeiro, RJ, Brazil.
Leandro Rocha
LR
Messias
Universidade Federal Fluminense, Rio de Janeiro, RJ, Brazil.
Aryanne Guimarães
AG
Ferreira
Universidade Federal Fluminense, Rio de Janeiro, RJ, Brazil.
Sandra Marina Ribeiro de
SM
Miranda
Universidade Federal Fluminense, Rio de Janeiro, RJ, Brazil.
José Antônio Caldas
JA
Teixeira
Universidade Federal Fluminense, Rio de Janeiro, RJ, Brazil.
Jader Cunha de
JC
Azevedo
Hospital Federal dos Servidores do Estado do Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
Ana Carolina Nader Vasconcelos
AC
Messias
Universidade Federal Fluminense, Rio de Janeiro, RJ, Brazil.
Elisabeth
E
Maróstica
Universidade Federal Fluminense, Rio de Janeiro, RJ, Brazil.
Claudio Tinoco
CT
Mesquita
D019797:3-Iodobenzylguanidine; D058665:Adrenergic beta-1 Receptor Agonists / Q000627:therapeutic use; D000368:Aged; D001794:Blood Pressure / Q000502:physiology; D005080:Exercise Test / Q000379:methods; D005260:Female; D006333:Heart Failure / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000503:physiopathology*; D006801:Humans; D007457:Iodine Radioisotopes; D008297:Male; D008875:Middle Aged; D000068577:Nebivolol / Q000627:therapeutic use*; D010101:Oxygen Consumption / Q000187:drug effects; D011446:Prospective Studies; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D013318:Stroke Volume / Q000502:physiology; D014665:Vasodilator Agents / Q000627:therapeutic use*
D058665:Adrenergic beta-1 Receptor Agonists; D007457:Iodine Radioisotopes; D019275:Radiopharmaceuticals; D014665:Vasodilator Agents; D000068577:Nebivolol; D019797:3-Iodobenzylguanidine