Effects of Pegvisomant on left ventricular mass in refractroy acromegalic patients. a 4 years follow-up observational study

Objective: Since morpho-functional bi-ventricular impairment (i.e. left ventricular hypertrophy, LVH) is described in Acromegalic patients (pts), the effects of medical and surgical treatments have been previously examined. Pegvisomant (PegV) is a GH receptor antagonist, indicated for acromegalic pts with unsuccessful surgical, radiation, and/or medical treatments, with the goal of obtaining normal IGF-1 serum levels. Aim of this observational study is to evaluate the effect of PegV on left ventricularstructure. Methods: We evaluated seven consecutive pts (4 males, mean age was50.1SD 9.8 years), with active acromegaly, eligible to PegV treatment (mean disease duration before PegV: 8 years ± 3.2) by means of a 4 yy clinical and instrumental follow-up. Starting from 10 mg daily, PegV was titrated to reach the expected levels of IGF-1 for sex and age. All patients underwent to transthoracic echocardiogram (TTE) yearly from acromegaly diagnosis; in our study we considered the following TTE results: 2 years before starting PegV (T -2), at the enrolment for PegV therapy (T0) and, respectively, after two and four years of treatment (T2, T4). We compared left ventricular dimensions, geometry (LVEDD: left ventricle end-diastolic diameter; RWT: relative wall thickness) and mass (LVM and LVM index , expressed as g/h2.7). Students t test for paired data was used. Results: At six months therapy all pts normalized IGF-1 levels, which remained stable during the whole follow up. LVM and LVMi were significantly higher at T0 when compared with T-2 (before PegV: p< 0.05 for both) whereas significantly lower at T+2 (after 2 yy PegV therapy: p<0.05 vs T0 for both). The improvement trend was confirmed after 4 years PegV treatment (p<0.05 vs T0 and vs T+2 for both). Conclusions: In our study, successful PegV treatment (involving IGF-1 serum level normalization) seems to be effective in inducing a significant LV mass reduction, whereas previous treatments showed no effect (Fig.1). The observed LVM reduction after PevG treatment could play a role in improving the cardiovascular prognosis of hypertrophic acromegalic patients.