Chronic treatment with the somatostatin analog octreotide improves cardiac abnormalities in acromegaly

The aim of this study was to investigate the effects of a 6-month octreotide treatment on cardiac mass and function by means of Doppler echocardiography in 11 normotensive patients affected with active acromegaly. The GH and insulin-like growth factor-I levels were normalized during octreotide therapy from 34 +/- 6.5 and 767.4 +/- 72.4 micrograms/L to 4.6 +/- 0.9 and 235 +/- 10.3 micrograms/L, respectively (P < 0.001; mean +/- SEM). After the 6-month treatment, we observed a significant decrease in the left ventricular mass index from 138 +/- 11 to 116 +/- 13 g/m2 (P < 0.001) and in the mean wall thickness/internal end-diastolic radius ratio from 0.47 +/- 0.1 to 0.44 +/- 0.1 (P < 0.001). No significant differences were found in systolic function indices, whereas diastolic filling indices improved over the course of the therapy; the isovolumic relaxation time decreased from 115 +/- 6 to 100 +/- 6 ms (P < 0.05), tricuspid late diastolic filling velocities decreased from 41 +/- 3 to 36 +/- 2 cm/s (P < 0.03), and tricuspid deceleration time decreased from 280 +/- 28 to 198 +/- 15 ms (P < 0.005); the ratio of early to late peak velocity of the right ventricular filling significantly increased from 1 +/- 0.01 to 1.3 +/- 0.1 (P < 0.03). A significant correlation was detected between left ventricular mass regression and increase in the early to late peak velocity ratio of the left ventricular filling (r = 0.62; P < 0.05). The results of this study show an improvement in cardiac structural and functional abnormalities during chronic treatment with octreotide, thus supporting the hypothesis of a specific heart disease secondary to high circulating GH levels.