Treatment with GH receptor antagonist in acromegaly: effect on cardiac arrhythmias.
OBJECTIVE
To evaluate the effects of short- and long-term treatment with pegvisomant (PEG) on arrhythmias in acromegalic patients resistant to long-term, high-dose therapy with somatostatin analogs (SA).


METHODS
Thirteen patients entered the study. all patients started peg at initial dose of 10MG daily and then titrated to 5MG every 6 weeks on the basis of IGF1. A standard 24-H electrocardiography registration was performed in all patients at baseline and after 6 AND 18 months of PEG to evaluate: mean (HR), maximum (MHR), and minimum (mHR) heart rate; pauses number (P) and duration (PD); supraventricular episodes (SEs) number and duration (SED); and ventricular ectopic beats (EB) number and duration (EBD). Left ventricular mass (LVM) was also evaluated by standard echocardiography.


RESULTS
A slight but not significant decrease in HR, MHR, and mHR was observed after 6-month PEG, whereas a significant decrease in HR (P=0.03), MHR (P=0.05), and mHR (P=0.05) was found after 18-month PEG compared with baseline. LVM significantly (P=0.05) correlated with MRH (r=-0.50) after short-term treatment, and with HR (r=-0.54) and mHR (r=-0.55) after long-term treatment. Long-term PEG induced the complete recovery of arrhythmias recorded at baseline in one patient and the improvement of rhythm disorders developed after 6-month therapy in another patient. The prevalence of conduction disturbances passed from 15 to 7.7% after long-term PEG.


CONCLUSIONS
Long-term treatment with PEG reduces HR, MHR, and mHR and improves rhythm abnormalities in acromegaly.
Department of Molecular and Clinical Endocrinology, University Federico II, Naples, Italy.
Renata S
RS
Auriemma
Rosario
R
Pivonello
Maria Cristina
MC
De Martino
Giuseppe
G
Cudemo
Ludovica F S
LF
Grasso
Mariano
M
Galdiero
Ylenia
Y
Perone
Annamaria
A
Colao
D000172:Acromegaly / Q000188:drug therapy* / Q000503:physiopathology; D000328:Adult; D001145:Arrhythmias, Cardiac / Q000188:drug therapy*; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D019382:Human Growth Hormone / Q000031:analogs & derivatives* / Q000627:therapeutic use; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011986:Receptors, Somatotropin / Q000037:antagonists & inhibitors*
D011986:Receptors, Somatotropin; D019382:Human Growth Hormone; C406545:pegvisomant