Treatment with GH receptor antagonist in acromegaly: effect on cardiac arrhythmias

Abstract

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). Materials and methods: Thirteen patients entered the study. All patients started PEG at initial dose of 10 mg daily and then titrated to 5 mg 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 (PZ0.03), MHR (PZ0.05), and mHR (PZ0.05) was found after 18-month PEG compared with baseline. LVM significantly (PZ0.05) correlated with MRH (rZK0.50) after short-term treatment, and with HR (rZK0.54) and mHR (rZK0.55) 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.European Journal of Endocrinology 168 15-22

Does pegvisomant treatment expertise improve control of resistant acromegaly? The Italian ACROSTUDY experience

“…In our study, significant reductions in SBP, DBP, and glycemic levels were observed only in group A patients, despite hypertension has been reported as adverse event in 2 % of cases in this group. We could speculate that this effect, which could be also due to the younger patients' age in this group as well as an overall better patients' management, was associated with a decrease in cardiovascular risk in this group, which is one of the most important endpoints of acromegaly treatment [30,31]. Unfortunately, data concerning antihypertensive treatment, as well as other information concerning glucose metabolism (e.g., number of patients with diabetes mellitus or IGT/IFG and related treatment) were not available, so we cannot know if the improvement was due to pegvisomant treatment or to changes in antihypertensive and/or antidiabetic drugs.…”

Effects of long-term combined treatment with somatostatin analogues and pegvisomant on cardiac structure and performance in acromegaly

“…In patients converted from SA to PEG monotherapy, IGF-I normalization improves glucose tolerance and insulin sensitivity [23,[33][34][35][36][37], also ameliorating blood pressure in hypertensive patients [23]. Arrhythmias rate [38] and endothelial dysfunction [39] also improved after long-term PEG monotherapy. Noteworthy, 18-month PEG treatment improves cardiomyopathy, therefore preventing the development or the progression of cardiac failure [40].…”

The beneficial effect of acromegaly control on blood pressure values in normotensive patients

“…Although these findings could have been influenced by other medication in HT patients, a direct effect of the medical treatment for acromegaly was found in NTs, which is in keeping with a previous study of the effects of treatment with somatostatin analogues on HR in acromegaly 36 and a recent prospective analysis of the effect of GH receptor antagonist on cardiac arrhythmias. 37 However, whether or not such effects on HR may influence BP response in a subset of acromegalic patients is currently unknown.…”