Regression of acromegalic left ventricular hypertrophy after lanreotide (a slow-release somatostatin analog)

Acromegaly: Cardiovascular risk factors, cardiovascular manifestations and early vascular alterations in relation to disease activity

Acromegaly is associated with increased cardiovascular morbidity and mortality. 49 acromegaly patients were evaluated for presence of cardiovascular risk factors and manifestations using 2D-Echocardiography, strain, strain-rate, carotid intima media thickness (CIMT) and flow mediated dilatation (FMD) and correlated with disease activity. 32 patients with growth hormone (GH) level >1 ng/ml were considered active. Patients with active disease have more LV dysfunction as assessed by strain(p-0.031) and strain rate(p-0.001); trend towards lower ejection fraction(p-0.11) with significant correlation to GH(cc -0.252,p-0.05). Patient with active disease have reduced FMD(p- 0.042); with no difference in prevalence of cardiovascular risk factors and CIMT inrelation to disease activity.

Growth hormone control and cardiovascular function in patients with acromegaly

BACKGROUND

Acromegaly is associated with cardiovascular alterations. Up to 50% acromegalic patients suffered from treatment failure after multiple modalities. We investigated correlation between cardiovascular function and control of growth hormone (GH) in acromegalic patients following transsphenoidal adenomectomy (TSA).

METHODS

We recruited acromegalic patients who had undergone TSA between 2006 and 2014 in this cross-sectional study. Patients were assigned to group 1, controlled acromegaly (GH <1.0 ng/mL and normalized insulin-like growth factor-1 [IGF-1]); group 2, partially controlled acromegaly (either GH >1.0 ng/mL or non-normalized IGF-1); or group 3, uncontrolled acromegaly (GH >1.0 ng/mL and non-normalized IGF-1). Echocardiography evaluated the left ventricular mass index, left ventricular ejection fraction, and the early transmitral filling velocity (E)-to-late transmitral filling velocity (A) and the E-to-the early diastolic mitral annular velocity (E') ratios. Carotid tonometry evaluated the intima-media thickness of the carotid artery, carotid-femoral pulse wave velocity, augmentation index, aortic characteristic impedance (Zc), and pulse pressure amplification.

RESULTS

Thirty-three patients participated in this study. Fourteen of the 33 patients were males (42%). Mean age at diagnosis was 50.33 years (SD 18.45). Compared to patients in group 1, patients in group 3 had younger age and shorter years after operation, without statistical significance. Cumulative GH levels were progressively higher from group 1 to group 3, without statistical significance. The groups did not differ with respect to cardiovascular structure and function evaluated by echocardiography and carotid tonometry. Only Zc value had a difference that was of borderline significance (group 1: 109.13 ± 32.99; group 2: 129.30 ± 32.27; group 3: 159.56 ± 77.4 dynes × s/cm5; ANOVA p = 0.088; p = 0.086 for group 1 vs group 3).

CONCLUSION

In the patients with acromegaly who had undergone TSA, cardiac structure and vascular stiffness did not differ among the groups with different levels of GH control.

Effects of somatostatin analog treatment on cardiovascular parameters in patients with acromegaly: A systematic review

Background:

There is a belief that in patients with acromegaly, first-generation somatostatin analogs (SSAs) might improve cardiovascular (CV) structure and function. However, most published clinical trials involved only a few patients and their results are rather variable. We aimed to conduct a systematic review on available studies on the impact of these drugs on CV parameters.

Materials and Methods:

A literature search was conducted in MEDLINE (OVID), EMBase, Cochrane, and ISI Web of Science for citations published until April 30 2018 to identify studies on our objective that considered changes in CV parameters. For this search, we established a Boolean search strategy using keywords related to “acromegaly,” “Somatostatin analog,” and “cardiovascular diseases and parameters.” All study types except for case reports or conference abstracts were included. Twenty-four studies (n = 558) fulfilled the inclusion criteria and were selected for final analysis.

Results:

In 12 studies (n = 350), decrease in heart rate (HR) and in 4 studies (n = 128), decrease in blood pressure (BP) was significant. In 15 studies (n = 320), left ventricular mass index (LVMi) changes were significant. In 9 studies (n = 202), the early diastole to peak velocity flow in late diastole (E/A ratio) was evaluated, and in 5 of them (n = 141), the improvement was significant. Eighteen studies (n = 366) examined changes in left ventricular ejection fraction (LVEF), 5 of which (n = 171) reported that these changes were significant. Decrease of left ventricular end-diastolic diameter was reported in only 2 studies (n = 27).

Conclusion:

We found that first-generation SSAs have a beneficial effect on cardiac parameters such as HR and LVMi. For other parameters such as LVEF, BP, LV diameter, and E/A ratio, we were not able to draw a firm conclusion.

AMERICAN ASSOCIATION OF CLINICAL ENDOCRINOLOGISTS AND AMERICAN COLLEGE OF ENDOCRINOLOGY DISEASE STATE CLINICAL REVIEW: MANAGEMENT OF ACROMEGALY PATIENTS: WHAT IS THE ROLE OF PRE-OPERATIVE MEDICAL THERAPY?

OBJECTIVE

Acromegaly is a complex disease characterized by growth hormone (GH) excess originating in most cases from a pituitary tumor. The goals of treatment include removing the tumor or reducing tumor burden, normalizing GH secretion and insulin-like growth factor 1 levels, and preserving normal pituitary function if possible. Surgery by an experienced neurosurgeon is still considered first-line therapy, especially in cases with small tumors. In the last few decades, significant progress in the development of selective pharmacologic agents has greatly facilitated the management of active acromegaly, with agents such as somatostatin-receptor ligands (SRLs), GH-receptor antagonists, and dopamine agonists. In addition to adjuvant treatment, pre-operative medical therapy and primary therapy in de novo patients are increasingly employed.

METHODS

A United States National Library of Medicine PubMed search (through July 2014) was conducted for the following terms: acromegaly, pre-operative medical therapy, somatostatin-receptor ligands, and somatostatin analogs. Articles not in English and those not in peer-reviewed journals were excluded. In reviewing pertinent articles, focus was placed on biochemical and other postoperative outcomes of medical therapy.

RESULTS

An analysis of the full effect of pre-operative use of SRLs on surgical outcomes (remission rates and peri-operative complications) is limited by heterogeneity of methodology, low overall surgical cure rates, and different study designs. The assumption that SRL use prior to surgery reduces peri-operative surgical risk has yet to be proven. A variable degree of tumor shrinkage with preoperative SRLs is observed. Likewise, SRL treatment 3 months before surgery may improve surgical remission rates in the short term; however, positive results do not persist in the long term.

CONCLUSION

We consider that medical therapy before surgery could play a role in carefully selected patients, but treatment should be individualized. Primary medical therapy with a SRL may be considered in patients with macroadenomas without local mass effects on the optic chiasm, as SRLs have been shown to reduce tumor size and control GH hypersecretion. However, the data are insufficient to support general use of a SRL prior to surgery in order to improve post-surgery biochemical outcomes. Theoretically, patients with severe cardiac and respiratory complications due to acromegaly could potentially benefit from pre-operative SRLs in order to reduce peri-operative morbidity. Further investigation and investment in large randomized long-term clinical trials are needed to define the precise role and duration of pre-surgical medical treatment in acromegaly patients.

Cardiovascular Disease and Sleep-Disordered Breathing in Acromegaly

Treatment goals in acromegaly include symptom relief, tumour control and reversal of the excess morbidity and mortality associated with the disorder. Cardiovascular complications include concentric biventricular hypertrophy and cardiomyopathy, hypertension, valvular heart disease and arrhythmias, while metabolic disturbance (insulin resistance/diabetes mellitus, dyslipidaemia) further increases the risk of cardiovascular and cerebrovascular events. Sleep-disordered breathing (in the form of sleep apnoea) is also common in patients with acromegaly and may exacerbate cardiovascular dysfunction, in addition to contributing to impaired quality of life. Accordingly, and in keeping with evidence that cardiorespiratory complications in acromegaly are not automatically reversed/ameliorated simply through the attainment of 'safe' growth hormone and insulin-like growth factor 1 levels, recent guidelines have emphasised the need not only to achieve stringent biochemical control, but also to identify and independently treat these comorbidities. It is important, therefore, that patients with acromegaly are systematically screened at diagnosis, and periodically thereafter, for the common cardiovascular and respiratory manifestations and that biochemical targets do not become the only treatment goal.

Recent advances in the management of acromegaly

Acromegaly is a rare condition of GH excess associated with significant morbidities (e.g. hypertension, glucose intolerance or diabetes mellitus, cardiac, cerebrovascular, respiratory disease and arthritis) and, when uncontrolled, high mortality. Surgery, medical treatment and radiotherapy remain our therapeutic tools. Advances in these options during the last years have offered further perspectives in the management of patients and particularly those with challenging tumours; the impact of these on the long-term morbidity and mortality remains to be assessed.

Improvement of cardiac parameters in patients with acromegaly treated with medical therapies

In acromegaly, growth hormone (GH) and insulin-like growth factor-1 (IGF-1) excess results in a specific cardiomyopathy characterized by concentric cardiac hypertrophy primarily associated with diastolic dysfunction that can lead to impaired systolic function and eventually heart failure. This review of the literature evaluates the effect of therapeutic intervention on cardiac parameters. Clinical studies investigating the impact of treatments for acromegaly on cardiac function published between January 1980 and January 2009 were identified through electronic searches of Medline. Suppression of GH and IGF-1 following surgery or medical treatment with somatostatin analogue therapy is effective in decreasing left ventricular (LV) hypertrophy, with subsequent improvement in cardiac function. First-line treatment with somatostatin analogues resulted in improved cardiac outcome compared with first-line surgery, possibly due to somatostatin analogues acting directly through somatostatin receptors on cardiac cells. Additional cardiac improvement has been reported when somatostatin analogue treatment was combined with surgery. In patients where complete biochemical control was not achieved, an improved cardiac performance following treatment with somatostatin analogues has been reported. Treatment with pegvisomant has been demonstrated to reduce LV hypertrophy and improve diastolic and systolic performance. In contrast, reports have suggested that treatment with the dopamine agonist cabergoline increased the incidence of valvular heart disease. Although surgery and somatostatin analogues are effective in improving cardiomyopathy, a greater beneficial effect is observed with somatostatin analogue treatment. Selected patients with acromegaly should consider first-line therapy or pre-treatment with somatostatin analogues prior to surgery to achieve biochemical control and improve cardiac dysfunction.

Medical therapy of acromegaly

This paper outlines the present status of medical therapy of acromegaly. Indications for permanent postoperative treatment, postirradiation treamtent to bridge the interval until remission as well as primary medical therapy are elaborated. Therapeutic efficacy of the different available drugs-somatostatin receptor ligands (SRLs), dopamine agonists, and the GH antagonist Pegvisomant-is discussed, as are the indications for and efficacy of their respective combinations. Information on their mechanism of action, and some pharmakokinetic data are included. Special emphasis is given to the difficulties to define remission criteria of acromegaly due to technical assay problems. An algorithm for medical therapy in acromegaly is provided.

Clinical, quality of life, and economic value of acromegaly disease control

Although acromegaly is a rare disease, the clinical, economic and health-related quality of life (HRQoL) burden is considerable due to the broad spectrum of comorbidities as well as the need for lifelong management. We performed a comprehensive literature review of the past 12 years (1998-2010) to determine the benefit of disease control (defined as a growth hormone [GH] concentration <2.5 μg/l and insulin-like growth factor [IGF]-1 normal for age) on clinical, HRQoL, and economic outcomes. Increased GH and IGF-1 levels and low frequency of somatostatin analogue use directly predicted increased mortality risk. Clinical outcome measures that may improve with disease control include joint articular cartilage thickness, vertebral fractures, left ventricular function, exercise capacity and endurance, lipid profile, and obstructive apnea events. Some evidence suggests an association between controlled disease and improved HRQoL. Total direct treatment costs were higher for patients with uncontrolled compared to controlled disease. Costs incurred for management of comorbidities, and indirect cost could further add to treatment costs. Optimizing disease control in patients with acromegaly appears to improve outcomes. Future studies need to evaluate clinical outcomes, as well as HRQoL and comprehensive economic outcomes achieved with controlled disease.

[Outcome of somatostatin analogue treatment in acromegaly]

During the past decade the importance of medical therapy, especially treatment with somatostatin analogues has increased significantly in patients with active acromegaly.

AIMS

Authors analyzed the outcome of somatostatin analogue treatment in acromegalic patients evaluated and followed up at the 2nd Department of Medicine, Faculty of Medicine, Semmelweis University, during the past 10 years.

PATIENTS AND METHODS

Changes in serum growth hormone (GH) and insulin-like growth factor-1 (IGF-1) concentration, as well as morphologic changes of pituitary adenomas followed by MRI scans were evaluated and compared in 32 acromegalic patients (26 women, 6 men) during long-term somatostatin analogue treatment (mean+/-SE, 3.1+/-0.3 years, range, 1-7 years). Primary somatostatin analogue treatment was applied in 10 patients (7 women and 3 men), whereas 15 patients (14 women and 1 man) had pituitary surgery and 7 patients (5 women and 2 men) underwent both pituitary surgery and irradiation therapy prior to somatostatin analogue treatment.

RESULTS

After a 3-month treatment with somatostatin analogues, both serum GH and IGF-1 levels decreased significantly and they remained around the same decreased levels throughout the treatment period. Serum GH decreased from 15.7+/-4.9 to 5.5+/-1.4 ng/ml, and serum IGF-1, expressed as a percentage of the upper limit of age- and sex-adjusted reference value, decreased from 204+/-14% to 135+/-12% at the end of treatment. The efficacy of somatostatin analogue treatment was not influenced by surgical or surgical and irradiation therapies which were applied prior to medical treatment. At the end of treatment 36.7% of patients had safe serum GH (<2.5 ng/ml), while serum IGF-1 returned below the upper limit of age- and sex-adjusted reference range in 41.4% of patients. Pituitary MRI showed regression of the adenoma in 46% of patients, and none of the patients had progression of the pituitary adenoma.

CONCLUSIONS

Somatostatin analogues are effective therapeutic options for acromegalic patients when primary surgical treatment cannot be performed due to complications and associated disorders, or in patients whose acromegaly remains active after pituitary surgery or after pituitary surgery and irradiation.

Lanreotide for the treatment of acromegaly

Lanreotide is an eight-amino acid peptide, which is an analog of the native somatostatin peptide, physiological inhibitor of growth hormone (GH). The drug shows high binding affinity for somatostatin receptors, SSTR2 and SSTR5, which is the primary mechanism considered to be responsible for decreasing GH secretion and GH cell proliferation in acromegaly. Two different formulations of lanreotide are currently available: lanreotide slow release, which requires intramuscular injection every 7-14 days, and lanreotide autogel, which requires deep subcutaneous injection every 4-8 weeks. Several studies have been published to date on the use of lanreotide in acromegaly. Antisecretory efficacy has been reported in 35%-70% of cases; this huge variability is probably explained by different indications (eg, primary or adjunctive postsurgical treatment), or the fact that some studies were based on patients known to be responders to somatostatin analogs. As a primary treatment, antisecretory efficacy was very similar, confirming the possibility of lanreotide as an option in cases of unsuccessful surgery, contraindication, or surgery refusal. Lanreotide also has antitumoral effects as it induces a decrease in tumor volume of [Symbol: see text]25% in 30%-70% of patients. This could be beneficial before transsphenoidal surgery, as a pretreatment, to decrease tumor volume and ease surgery; however, to date, advantages in terms of final remission or uncured status remain a matter of debate. Side effects are rare; the most frequent being gastrointestinal discomfort and increased risk of gallstone formation, and glucose metabolism modifications. Comparison with the other somatostatin analog, octreotide, tends to show identical levels of efficacy between both drugs. Lanreotide thus seems to be an effective treatment in acromegaly. To date, however, lanreotide is still considered as only suspending GH secretion, thus requiring prolonged and costly treatment.

Effects of lanreotide Autogel on growth hormone, insulinlike growth factor 1, and tumor size in acromegaly: a 1-year prospective multicenter study

OBJECTIVE

To evaluate the safety and effectiveness of lanreotide Autogel on growth hormone and insulinlike growth factor 1 (IGF-1) concentrations and tumor size in patients with acromegaly.

METHODS

Between September 2004 and March 2006, patients with active acromegaly who had not previously been treated with somatostatin analogues or received irradiation were enrolled in a 1-year, prospective, open, multicenter study. Lanreotide Autogel was injected subcutaneously starting with 90 mg every 4 weeks for 2 cycles and then individually titrated, aiming for safe growth hormone concentrations (<2.5 ng/mL) and normal age-matched IGF-1 concentrations. Tumor shrinkage, clinical score, pituitary function, and safety parameters were evaluated.

RESULTS

Twenty-seven patients (15 women, 12 men) were enrolled. One patient withdrew because of treatment intolerance, and 5 proceeded to neurosurgery 6 months into the study. Lanreotide Autogel was the primary treatment in 19 patients (4 with microadenoma, 15 with macroadenoma) and the adjuvant treatment in 8 patients in whom it followed a previous unsuccessful neurosurgery. In the 26 patients, safe growth hormone values were achieved in 11 (42%), normal IGF-1 values in 14 (54%), and both targets were achieved in 10 (38%). Tumors shrank in 16 of the 22 patients (73%) in whom tumor shrinkage could be evaluated. The maximal vertical diameter of the tumor decreased by a mean of 24% (range, 0% to 50%), from 14.4 +/- 8.4 mm to 10.4 +/- 7 mm, and tumor volume decreased by a mean of 44% (range, 0% to 76%), from 2536 mm3 (range, 115-7737 mm(3)) to 1461 mm(3) (range, 63-6217 mm(3)) (both P<.015). Symptom scores and lipid levels significantly improved. In the 26 patients, glucose metabolism deteriorated in 3 (12%) and improved in 4 (15%). New biliary alterations appeared in 26%. Pituitary function and safety parameters did not change.

CONCLUSIONS

Lanreotide Autogel treatment, titrated for optimal hormonal control, effectively controls IGF-1 and growth hormone levels, shrinks tumors, reduces acromegalic symptoms, and is well tolerated.

Octreotide-LAR vs lanreotide-SR as first-line therapy for acromegaly: a retrospective, comparative, head-to-head study

No head-to-head comparisons are available to analyze the efficacy of octreotide (LAR) and lanreotide (LAN) as first-line treatment of acromegaly.We compared the efficacy of these two drugs in 54 newly diagnosed patients (21 women, 33 men), 27 treated with LAR (10-30 mg every 28 days) and 27 with LAN (60-90 mg/28 days), for 12 months. Each LAR-treated patient was matched with one LAN-treated patient as for GH levels, sex, and age (+/-5 yr). Outcome measures were GH and IGF-I levels and tumor shrinkage and secondarily classical cardiovascular risk factors (total/HDL-cholesterol ratio, glucose tolerance), blood pressure and drug tolerability. In LAR- and in LAN-treated patients, respectively: GH and IGF-I were controlled in 21 (77.7%) and in 16 patients (59.3%; p=0.26); tumor shrinkage was absent (<25%) in 4 and 5 patients (p=1), mild (25.1-50%) in 9 and 12 (p=0.57), moderate (50.1-75%) in 10 and 6 (p=0.37) and notable (>75%) in 4 and 4 patients (p=1). The total/HDL-cholesterol ratio and insulin levels significantly decreased while glucose levels significantly increased in both groups. None of the patients with normal glucose tolerance at diagnosis developed diabetes mellitus. Side effects were mostly at the gastrointestinal level and were similar with both drugs. In conclusion, newly diagnosed patients with acromegaly treated with LAR and LAN have no significantly different prevalence of disease control, tumor shrinkage, improvement of cardiovascular risk markers and side effects. Therefore, both drugs can be safely employed as first-line therapy of acromegaly.

GH and IGF-I excess control contributes to blood pressure control: results of an observational, retrospective, multicentre study in 105 hypertensive acromegalic patients on hypertensive treatment

CONTEXT

Approximately one-third of patients with acromegaly have concomitant hypertension. The outcome of hypertension after treatment of acromegaly is unknown.

OBJECTIVE

To evaluate the role of GH and IGF-I control on systolic (SBP) and diastolic blood pressure (DBP) levels.

PATIENTS

One hundred and five hypertensive patients (60 women, 45 men) with active disease receiving treatment for hypertension at their diagnosis of acromegaly.

DESIGN

Observational, retrospective, multicentre.

MEASUREMENTS

At diagnosis and after 24 months (median) of treatment we measured serum GH and IGF-I levels, blood pressure levels, left ventricular (LV) mass index (LVMi), early-to-late mitral flow velocity (E/A, as a measure of diastolic function) and LV ejection fraction (LVEF, as a measure of systolic function).

RESULTS

At the diagnosis of acromegaly, hypertension was mild in 41.1% and severe in 58.9%. Serum GH and IGF-I levels did not differ in patients with mild or severe hypertension. After 24 months of treatment, all patients had a notable decrease in both GH and IGF-I levels, and achieved significantly lower levels of DBP, heart rate and LVMi; 76 patients (71%) had achieved control of GH and IGF-I levels. Only the patients with controlled acromegaly achieved significantly lower SBP levels and significantly improved cardiac systolic and diastolic function. A higher dose of antihypertensive drugs and/or an increased number of drugs to control hypertension were significantly greater in patients with uncontrolled (32.3%) than in those with controlled acromegaly (7.8%; P = 0.004).

CONCLUSION

Hypertensive patients with controlled acromegaly achieved improved control of hypertension and of cardiac diastolic and systolic function. The use of antihypertensive drugs was significantly less in patients achieving control of acromegaly.

The GH-IGF-I axis and the cardiovascular system: clinical implications

BACKGROUND

GH and IGF-I affect cardiac structure and performance. In the general population, low IGF-I has been associated with higher prevalence of ischaemic heart disease and mortality. Both in GH deficiency (GHD) and excess life expectancy has been reported to be reduced because of cardiovascular disease.

OBJECTIVE

To review the role of the GH-IGF-I system on the cardiovascular system.

RESULTS

Recent epidemiological evidence suggests that serum IGF-I levels in the low-normal range are associated with increased risk of acute myocardial infarction, ischaemic heart disease, coronary and carotid artery atherosclerosis and stroke. This confirms previous findings in patients with acromegaly or with GH-deficiency showing cardiovascular impairment. Patients with either childhood- or adulthood-onset GHD have cardiovascular abnormalities such as reduced cardiac mass, diastolic filling and left ventricular response at peak exercise, increased intima-media thickness and endothelial dysfunction. These abnormalities can be reversed, at least partially, after GH replacement therapy. In contrast, in acromegaly chronic GH and IGF-I excess causes a specific cardiomyopathy: concentric cardiac hypertrophy (in more than two-thirds of the patients at diagnosis) associated to diastolic dysfunction is the most common finding. In later stages, impaired systolic function ending in heart failure can occur, if GH/IGF-I excess is not controlled. Abnormalities of cardiac rhythm and of cardiac valves can also occur. Successful control of acromegaly is accompanied by decrease of the left ventricular mass and improvement of cardiac function.

CONCLUSION

The cardiovascular system is a target organ for GH and IGF-I. Subtle dysfunction in the GH-IGF-I axis are correlated with increased prevalence of ischaemic heart disease. Acromegaly and GHD are associated with several abnormalities of the cardiovascular system and control of GH/IGF-I secretion reverses (or at least stops) cardiovascular abnormalities.

Therapeutic options in the management of acromegaly: focus on lanreotide Autogel

BACKGROUND

In acromegaly, expert surgery is curative in only about 60% of patients. Postoperative radiation therapy is associated with a high incidence of hypopituitarism and its effect on growth hormone (GH) production is slow, so that adjuvant medical treatment becomes of importance in the management of many patients.

OBJECTIVE

To delineate the role of lanreotide in the treatment of acromegaly.

METHODS

Search of Medline, Embase, and Web of Science databases for clinical studies of lanreotide in acromegaly.

RESULTS

Treatment with lanreotide slow release and lanreotide Autogel((R)) normalized GH and insulin-like growth factor-I (IGF-I) concentrations in about 50% of patients. The efficacy of 120 mg lanreotide Autogel((R)) on GH and IGF-I levels was comparable with that of 20 mg octreotide LAR. There were no differences in improvement of cardiac function, decrease in pancreatic beta-cell function, or occurrence of side effects, including cholelithiasis, between octreotide LAR and lanreotide Autogel(R). When postoperative treatment with somatostatin analogs does not result in normalization of serum IGF-I and GH levels after noncurative surgery, pegvisomant alone or in combination with somatostatin analogs can control these levels in a substantial number of patients.

Somatostatin agonists for treatment of acromegaly

The discovery of somatotropin-release inhibitory factor (SRIF) in hypothalamic extract in 1970 led to the synthesis of the first somatostatin analog octreotide, discovery of five somatostatin receptor subtypes, and development of additional somatostatin receptor ligands (SRL) as pharmacotherapy for acromegaly and other neuroendocrine tumors. Long-acting formulations of SRL (octreotide LAR Depot, lanreotide SR and lanreotide autogel) assure improved patient compliance with weekly up to monthly injections, and are commonly used as primary or adjuvant treatment of acromegaly. We review SRL currently available, emphasizing long-acting compounds and their efficacy in controlling acromegaly. Disease control is evaluated by biochemical markers, tumor shrinkage, and disease-symptom improvement balanced against drug-related side effects.

Acromegaly

Acromegaly is caused by growth hormone hypersecretion, mostly from a pituitary adenoma, driving insulin-like growth factor 1 overproduction. Manifestations include skeletal and soft tissue growth and deformities; and cardiac, respiratory, neuromuscular, endocrine, and metabolic complications. Increased morbidity and mortality require early and tight disease control. Surgery is the treatment of choice for microadenomas and well-defined intrasellar macroadenomas. Complete resection of large and invasive macroadenomas rarely is achieved; hence, their low rate of disease remission. Pharmacologic treatments, including long-acting somatostatin analogs, dopamine agonists, and growth hormone receptor antagonists, have assumed more importance in achieving biochemical and symptomatic disease control.

The long-term cardiovascular outcome of different GH-lowering treatments in acromegaly

The aim of this longitudinal study was to evaluate the echocardiographic outcome of acromegalic heart disease in patients undergoing different therapeutic approaches, in order to investigate whether SSA could provide therapeutic advantages as compared with neurosurgery. In total of 36, consecutive patients undergoing SSA treatment after neurosurgery were enrolled in this study (Gr.Surg.-SSA). After 12 months of treatment, 21 patients had a controlled disease, while the remaining 15 patients displayed uncontrolled disease. Twelve acromegalic patients who did not undergo SSA treatment due to controlled disease after neurosurgery were enrolled as control group (Gr.Surg). The echocardiographic-Doppler study was performed before neurosurgery and after 12-months of follow-up. After follow-up, a significant reduction in serum GH and IGF-I values, Left Ventricular Mass index (LVMi) and LVH rate with an improvement in diastolic function was observed in both groups of patients. We found a significant reduction of LVMi either in patients with controlled disease or in those with poorly controlled disease undergoing SSA treatment. Diastolic function and of LVH percentage improved in all groups, but significantly so only in controlled patients, no significant difference in any echocardiographic parameters and in the prevalence of the LVH rate were observed between the three groups of patients at the end of follow-up. Therefore, our data appear to show that for echographic parameters medical treatment additive beneficial effects is compared to neurosurgery alone. SSA also appears to contribute to the improvement of acromegalic cardiomyopathy also in patients who did not achieve biochemical control of the disease.

Impact of somatostatin analogs on the heart in acromegaly: a metaanalysis

CONTEXT

Acromegaly can be complicated by cardiomyopathy. Treatment with somatostatin analogs has been shown to improve some cardiac parameters, but most published clinical trials involved few patients and were not randomized or controlled. In addition, their results are rather variable.

OBJECTIVE

The objective of the study was to conduct a metaanalysis aimed at obtaining a more accurate picture of the effect of somatostatin analogs on the heart in patients with acromegaly.

DESIGN

We systematically reviewed all studies of somatostatin analogs in acromegaly. Eighteen studies were identified in three databases. We conducted a combined analysis of the effects of somatostatin analogs by using the overall effect size to evaluate significance and by computing the weighted mean differences with and without treatment to assess the effect size.

RESULTS

Somatostatin analog treatment was associated with significant reductions in the heart rate [-5.8 (2.1) beats/min], the left ventricular mass index [-22.3 (6.7) g/m(2)], interventricular septum thickness [-0.3 (0.2) mm], left ventricular posterior wall thickness [-0.8 (0.4) mm], and the ratio of the E-wave and A-wave peak velocities of the mitral flow profile [0.2 (0.1)]. It was also associated with improved exercise tolerance [1.6 (0.4) min]. Trends toward beneficial effects were noted for the left ventricular end-diastolic dimension [-1.5 (2.2) mm] and the left ventricular ejection fraction [3.3% (1.7%)]. Overall effect sizes were not significant for blood pressure, left ventricular end-systolic dimension, or fractional shortening. Bigger improvements were observed in studies with larger falls in IGF-I and/or GH levels and studies of younger patients.

CONCLUSION

This metaanalysis confirms that somatostatin analog therapy aimed at achieving stringent control of serum GH/IGF-I concentrations in patients with acromegaly is associated with significant positive effects on morphological and functional hemodynamic parameters.

A case and review of acromegaly-induced cardiomyopathy and the relationship between growth hormone and heart failure: cause or cure or neither or both?

Growth hormone plays an integral role in the development and maintenance of structure and function of the heart. Specific involvement of the heart in acromegaly is termed acromegalic cardiomyopathy, manifested as concentric left ventricular hypertrophy and diastolic dys-function. Left untreated, it ultimately progresses to systolic heart failure. Heart failure from acromegalic cardiomyopathy is one of the most common causes of death in acromegaly. Current treatment options include different approaches to lower elevated growth hormone levels with improvement in symptoms, exercise tolerance, and echocardiographic improvement in regression of left ventricular hypertrophy and indices of diastolic dysfunction. On the other hand, growth hormone is essential for cardiac growth and function and exerts beneficial and protective effects on the cardiovascular system. Its potential role as adjunctive therapy in the treatment of heart failure as derived from experimental studies and clinical trials is discussed.

Presurgical treatment with somatostatin analogs in patients with acromegaly: effects on the remission and complication rates

Object

The question of whether preoperative therapy with somatostatin analogs can improve surgical outcome in acromegaly has not been definitively answered. In this paper, the authors report the effects of preoperative treatment with somatostatin analogs in a large sample of patients with acromegaly.

Methods

Between 1990 and 2003, 399 consecutive patients with acromegaly underwent surgery at the Istituto Scientifico San Raffaele. Thirty-three patients who had previously undergone surgery or radiation treatment, 48 patients treated with somatostatin analogs for fewer than 3 months, and patients who had stopped therapy for too long a time before surgery were excluded from the study. One hundred forty-three patients who had received somatostatin analogs prior to surgery (Group 1) were randomly matched to 143 patients who had never been treated with somatostatin analogs (Group 2). Matching criteria were tumor size and invasiveness into the cavernous sinus. Before surgery, Group 1 patients showed reduction of growth hormone levels to less than 50% of baseline in 64% of cases, but insulin-like growth factor–I was normalized in only 19.5%. Surgical remission occurred in 81 Group 1 patients (56.6%) and in 91 Group 2 patients (63.6%; p = 0.28). No significant difference in the remission rate was observed when cases were analyzed according to tumor size or invasiveness. Logistic regression analysis confirmed that pretreatment with somatostatin analogs was not associated with surgical outcome. Surgical morbidity was mild and similar in Group 1 and Group 2 patients (7 and 5.6%, respectively; p = 0.81). Surgical remission and complication rates in patients with acromegaly who received treatment with somatostatin analogs prior to surgery were not significantly different from those of matched patients who did not receive these agents.

Conclusions

At present, the routine use of presurgical therapy with somatostatin analogs for patients with acromegaly cannot be recommended.

Persistent diastolic dysfunction despite successful long-term octreotide treatment in acromegaly

INTRODUCTION

This study was designed to evaluate potential reversibility of left-ventricular (LV) dysfunction in patients with acromegaly following long-term control of disease. It is unknown whether the cardiac changes induced by acromegaly can be reversed completely by long-term strict control of growth hormone excess by octreotide.

PATIENTS AND METHODS

We compared LV systolic and diastolic function in inactive patients with acromegaly (n = 22), who were divided into patients with long-term control by octreotide (n = 14) and patients with long-term cure by surgery/radiotherapy (n = 8). We also assessed these parameters in patients with active acromegaly (n = 17).

RESULTS

In patients with active acromegaly, systolic function at rest was decreased by 18% (P < 0.01), LV mass index increased by 40% (P < 0.04) and isovolumetric relaxation time increased by 19% (P < 0.01), compared with patients with inactive acromegaly. These parameters were not different between well-controlled and cured patients. Using tissue Doppler imaging, the ratio between early and late diastolic velocity (E'/A' ratio) was decreased in active, compared with inactive acromegaly (0.75+/-0.07 versus 1.24+/-0.15; P < 0.01). This E'/A' ratio was considerably higher in cured, compared with octreotide-treated, patients (1.75+/-0.41 versus 1.05+/-0.1; P < 0.01).

CONCLUSION

Diastolic function is persistently and significantly more impaired in acromegalic patients with long-term control by octreotide than in surgically cured patients, which points to biological effects of subtle abnormalities in growth hormone secretion. Criteria for strict biochemical control of acromegaly should thus be reconsidered.

H9c2 cardiac muscle cells express all somatostatin receptor subtypes

The aim of the present study was to verify the hypothesis that SS receptor subtypes (SSTRs) are expressed by H9c2 cardiac muscle cells. SSTRs expression was investigated by RT-PCR and Western blot analysis at both mRNA and protein level. Our findings demonstrate that H9c2 cells express all SSTR subtypes I-5 (SSTRI-5) at the mRNA and protein level. Thus, H9c2 cells would represent a new model to study the direct biological activities of SS and its analogues at the cardiac level.

Systemic complications of acromegaly: epidemiology, pathogenesis, and management

This review focuses on the systemic complications of acromegaly. Mortality in this disease is increased mostly because of cardiovascular and respiratory diseases, although currently neoplastic complications have been questioned as a relevant cause of increased risk of death. Biventricular hypertrophy, occurring independently of hypertension and metabolic complications, is the most frequent cardiac complication. Diastolic and systolic dysfunction develops along with disease duration; and other cardiac disorders, such as arrhythmias, valve disease, hypertension, atherosclerosis, and endothelial dysfunction, are also common in acromegaly. Control of acromegaly by surgery or pharmacotherapy, especially somatostatin analogs, improves cardiovascular morbidity. Respiratory disorders, sleep apnea, and ventilatory dysfunction are also important contributors in increasing mortality and are advantageously benefitted by controlling GH and IGF-I hypersecretion. An increased risk of colonic polyps, which more frequently recur in patients not controlled after treatment, has been reported by several independent investigations, although malignancies in other organs have also been described, but less convincingly than at the gastrointestinal level. Finally, the most important cause of morbidity and functional disability of the disease is arthropathy, which can be reversed at an initial stage, but not if the disease is left untreated for several years.

Cardiac Abnormalities in Acromegaly

Cardiovascular disease is claimed to be one of the most severe complications of acromegaly, contributing significantly to mortality in this disease. In fact, an excess of growth hormone (GH) and insulin-like growth factor 1 (IGF-I) causes a specific derangement of cardiomyocytes, leading to abnormalities in cardiac muscle structure and function, inducing a specific cardiomyopathy. In the early phase of acromegaly the excess of GH and IGF-I induces a hyperkinetic syndrome, characterized by increased heart rate and increased systolic output. Concentric hypertrophy is the most common feature of cardiac involvement in acromegaly, found in more than two thirds of patients at diagnosis. This abnormality is commonly associated with diastolic dysfunction and eventually with impaired systolic function ending in heart failure, if the GH/IGF-I excess is left untreated. In addition, abnormalities of cardiac rhythm and of heart valves have also been described in acromegaly. The coexistence of other complications, such as arterial hypertension and diabetes mellitus, aggravates acromegalic cardiomyopathy. Successful control of acromegaly induces a decrease in left ventricular mass and an improvement in diastolic function, while the effects of GH/IGF-I suppression on systolic function are more variable. However, since cardiovascular alterations in young patients with short disease duration are milder than in those with longer disease duration, it is likely to be easier to reverse and/or arrest acromegalic cardiomyopathy in young patients with early-onset disease. In conclusion, careful assessments of cardiac function, morphology, and activity are required in patients with acromegaly. An early diagnosis and prompt effective treatment are important in order to reverse acromegalic cardiomyopathy.

Lanreotide 60 mg, a new long-acting formulation: effectiveness in the chronic treatment of acromegaly

Lanreotide (LAN) 60 mg (LAN60), a new long-acting formulation of LAN alleged to suppress GH/IGF-I hypersecretion for 28 d in acromegalic patients, was administered in a prospective open multicenter study to 92 patients with active acromegaly (61 women and 31 men, aged 20-79 yr). LAN60 was given as adjuvant treatment (AT) in 62 patients; the other 30 patients [primary treatment (PT)] were de novo (n = 20) or previously treated only by pharmacotherapy (n = 10). After wash-out from previous treatments, LAN60 was started im every 28 d for 3 injections; the dose was then individually tailored, aiming at lowering GH to less than 2.5 micro g/liter and IGF-I to the normal range. After a median follow-up of 24 months (range, 6-48 months), IGF-I normalized in 65% of patients, decreasing from 199 +/- 8% (expressed as a percentage of the upper limit of normal range; mean +/- SE) to 87 +/- 4% (P < 0.0001). GH fell to less than 2.5 microg/liter in 63% of patients and to less than 1 microg/liter in 25%, decreasing from 20 +/- 3 to 3 +/- 0.4 microg/liter (P < 0.0001). A progressive increase in the rate of IGF-I normalization was observed (from 49% at 1 yr to 77% at 3 yr). The rate of GH/IGF-I normalization was 72% at 36 months by Kaplan-Meier analysis. No tachyphylaxis was observed throughout the study. Shortening the interval between injections to 21 d improved GH/IGF-I suppression. PT and AT patients achieved similar final GH/IGF-I levels and rates of normalization. Tumor shrank in 39% of assessable patients and in 50% of PT. Plasma glucose levels did not change, and high density lipoprotein cholesterol increased (by 19.3 +/- 5.1%; P = 0.0215). Gallstones appeared or worsened in 13% of patients. LAN60 is a new, very effective and long-lasting formulation for the treatment of acromegaly. The persistence of a powerful suppression of GH/IGF-I levels, the progressive increase in the rate of IGF-I normalization, and the similarity in the efficacy achieved in PT and AT patients point to a role for LAN60 in the primary treatment of acromegaly.

How effective are current therapies for acromegaly?

Currently available therapies for acromegaly are transsphenoidal surgery (TSS), radiotherapy (RT) and medical therapy with the dopamine agonists and somatostatin analogues. The goals of these therapies for acromegaly are to normalize excessive hormone secretion, thus normalizing serum levels of growth hormone (GH) and of insulin-like growth factors (IGF-I), to reduce the clinical signs and symptoms of acromegaly and to reduce tumor size in order to relieve any symptoms due to tumor mass effect. These goals should be accomplished while preserving pituitary function and with as few side effects as possible.TSS, the initial choice of therapy in most patients, is the most effective therapy at reducing the signs and symptoms of mass effect such as visual or neurological compromise. TSS is potentially curative, but the outcome is highly dependent on the tumor size, the degree of tumor invasion and the expertise of the surgeon. TSS can achieve biochemical control with normalization of IGF-I in 80-90% of patients with microadenomas and in 50-60% of those with macroadenomas. RT may be used as adjunctive therapy after unsuccessful surgery. RT can lower GH levels and normalize IGF-I levels, but there is a long lag time before this effect is achieved. Biochemical control is not achieved for 6-10 years after conventional fractionated RT; the time to clinical effect after gamma knife RT seems to be shorter. The most common complication after all forms of RT for acromegaly is the development of new hypopituitarism. Medical therapy has assumed the major role as adjunctive therapy of acromegaly. The dopamine agonists used for the therapy of acromegaly include bromocriptine, quinagolide and cabergoline. Cabergoline seems to be the most efficacious of the dopamine agonists for the treatment of acromegaly, with normalization of IGF-I being achieved in up to 35% of patients treated. Dopamine agonists are generally not effective at reducing the size of pure GH-secreting pituitary tumors. Somatostatin analogues are the most effective medical therapy currently available for acromegaly. The clinically available long-acting somatostatin analogues are long-acting octreotide and slow-release lanreotide. Overall, IGF-I levels normalize in about 66% of patients treated with long-acting octreotide and in 48% of patients treated with lanreotide. About 30% of GH-secreting tumors treated with somatostatin analogues as adjunctive therapy will have some shrinkage, and the amount of shrinkage usually ranges between 20 and 50% of tumor size. Signs and symptoms of the disease improve in about two-thirds of patients treated with long-acting somatostatin analogues. Gastrointestinal side effects are common when initiating somatostatin analogue therapy, but these effects do not typically limit continued use. Multi-modality therapy for acromegaly is often needed to achieve disease control. However, even combinations of currently available therapies cannot achieve all the goals of therapy in many patients with acromegaly.

High prevalence of cardiac valve disease in acromegaly: an observational, analytical, case-control study

To characterize mitral and aortic valve abnormalities we performed M-mode, two-dimensional, and pulsed Doppler echocardiography in 42 patients with active acromegaly, 22 patients cured of acromegaly, and 64 controls pair-matched with the patients for sex and age. The overall prevalence of valve abnormalities was higher in both the active patients (86% vs. 24%; P < 0.0001) and the cured patients (73% vs. 9%; P < 0.0001) than in controls. Left ventricular hypertrophy was higher in active (81% vs. 29%; P < 0.0001), but not in cured (41% vs. 14%; P = 0.09) patients than in controls. Cardiac valve abnormalities were associated with left ventricular hypertrophy in both patients and controls, without any difference between them. Conversely, among subjects without left ventricular hypertrophy, mitral and aortic abnormalities were only present in the patients (75% of active and 54% of cured), but not in controls (3% of active controls and 0% of cured controls). In conclusion, patients with active acromegaly and those cured of the disease have a high prevalence of mitral and aortic abnormalities. The persistence of valve disease in patients with cured acromegaly is likely to be correlated with the persistence of left ventricular hypertrophy, which should be carefully and continuously monitored as an aspect of the risk of cardiac dysfunction in these patients.

Reversal of acromegalic cardiomyopathy in young but not in middle-aged patients after 12 months of treatment with the depot long-acting somatostatin analogue octreotide

BACKGROUND

Cardiovascular disease is the most frequent cause of death of patients with acromegaly.

AIM

To investigate whether young patients with a presumed short disease duration are more likely to reverse the acromegalic cardiomyopathy than older patients with longer disease duration.

DESIGN

An open prospective design.

PATIENTS

Ten young (aged < 40 years), and 12 middle-aged (41-59 years) patients with active acromegaly well controlled after 12 months of treatment with the depot formulation of octreotide (OCT-LAR); 22 sex- and age-matched healthy subjects as controls.

METHODS

Left ventricular (LV) mass (LVM) by echocardiography and performance by equilibrium radionuclide angiography were measured before and after 12 months of OCT-LAR treatment.

RESULTS

At study entry, none of the controls and 14 patients (63.4%) of whom six were young (chi2 = 17.7; P < 0.0001) had LV hypertrophy (LVH); none of the controls and four patients of whom one was young had insufficient LV ejection fraction (LVEF) at rest (< 50%); one control and 13 patients (59.1%) of whom five were young (chi2 = 12.7; P < 0.0001) had inadequate LVEF at peak exercise (deltaLVEF; < 5% increase of baseline). After 12 months, no change in haemodynamic and diastolic parameters was observed in both groups, except for a significant decrease in heart rate at peak exercise in young patients (P < 0.0001). The LVM index decreased significantly in both young (124.4 +/- 5.8 vs. 103.4 +/- 3.9 g/m2; P = 0.01) and middle-aged patients (140.9 +/- 7.9 vs. 117.8 +/- 6.6 g/m2; P = 0.03). LVH disappeared in 10 of 14 patients (71.4%): all six young and four of eight middle-aged patients (50%). LVEF at rest and at peak exercise increased significantly in both groups but deltaLVEF increased significantly only in young patients (1.5 +/- 2.9 vs. 13.7 +/- 5.2%, P = 0.04); it normalized in nine of 13 patients (69.2%), four of five young (80%) and four of eight middle-aged patients (50%). Exercise capacity (82.5 +/- 5.3 vs. 110.0 +/- 5.5 W, P = 0.005) and duration (7.3 +/- 0.3 vs. 9.9 +/- 0.4 min, P = 0.0003) also increased only in young patients.

CONCLUSIONS

The acromegalic cardiomyopathy is reversed in most young patients with short disease duration and achieving disease control after OCT-LAR treatment for 12 months, indicating that early diagnosis and effective treatment are essential.

The treatment of de novo acromegalic patients with octreotide-LAR: efficacy, tolerability and cardiovascular effects

AIM

Somatostatin analogues are normally used as adjunctive therapy to surgery and radiotherapy in management of acromegaly. We studied the effects of de novo OCT-LAR treatment on growth hormone (GH) suppression, tumour size, cardiovascular function, clinical symptoms, signs and quality of life in 9 newly diagnosed acromegalic patients.

METHODS

Patients commenced OCT-LAR 20 mg IM monthly for 2 months. Dose increased to 30 mg monthly if mean serum GH (MGH) > 5 mU/l (2 microg/litre) (7 patients). Treatment continued for 6 months. Cardiac function assessed by echocardiography at baseline and day 169. Left ventricular (LV) mass and ejection fraction (EF) calculated from 2D M-mode studies.

RESULTS

Serum GH demonstrated suppression in 8/9 patients (mean suppression 64.9% +/- 29.7%, range; 4-95.2%). MGH suppressed < 5 mU/ (2 microg/litre) in 3 (33%) patients. IGF-I and IGFBP3 normalised in 1 (12.5%) and 3 (38%) patients respectively. Tumour shrinkage seen in 30% patients. Eight patients were assessed by echocardiography. At baseline, 7 patients demonstrated abnormalities in LV mass and EF. At day 169, 6 patients demonstrated a fall and 1 an increase in LV mass. Overall there was no significant change in LV mass. A significant increase in EF was observed (p = 0.02). There were significant improvements in health perception (p = 0.01), fatigue (p < 0.05) and perspiration (p = 0.0039).

CONCLUSIONS

These data demonstrate OCT-LAR provides adequate control of acromegaly in a proportion of patients treated over 6 months. This is associated with improved LV function, evidenced by increased EF. Improved results are expected with longer-term treatment. OCT-LAR may be considered as primary treatment for acromegaly in selected patients.

Improvement of left ventricular hypertrophy and arrhythmias after lanreotide-induced GH and IGF-I decrease in acromegaly. A prospective multi-center study

We report the results of a prospective Italian multi-center study of the effects of lanreotide, a slow-release somatostatin analog, on left ventricular morphology and function and on the prevalence of ventricular arrhythmic events in 19 patients with active, newly diagnosed, uncomplicated acromegaly. Cardiac features were evaluated with Doppler-echocardiography and 24-h Holter ECG monitoring at baseline and after 6 months of lanreotide therapy. Fifteen patients (78.9%) had left ventricular hypertrophy. Lanreotide treatment significantly decreased the left ventricular mass (127.8+/-6.9 vs 140.7+/-7.1 g/m2, p<0.001) and left ventricular hypertrophy significantly disappeared in 6 of these patients. Treatment did not significantly affect systolic function, whereas it increased the Doppler-derived early-to-late mitral flow velocity, (E/A) ratio, of early-to-late trans-mitral flow velocity (1.34+/-0.1 vs 1.09+/-0.06, p=0.001). Stroke volume was slightly but not significantly increased after treatment, whereas systolic BP was significantly higher (134+/-14 vs 129+/-13 mmHg, p<0.05). The 24-h mean heart rate was significantly reduced after treatment (66.5+/-11 vs 71.5+/-20 beats/min, p<0.05). Supra-ventricular premature beats (>50/24 h) occurred in 16.6% of patients and were unaffected by treatment. Differently, ventricular premature beats (>50/24 h) occurred in 33.3% of patients before treatment vs 16.5%, after treatment. In conclusion, lanreotide reduced the left ventricular mass, and improved ventricular filling and ventricular arrhythmic profile.

Treatment of acromegaly improves myocardial abnormalities

BACKGROUND

Treatment for acromegaly decreases left ventricular (LV) mass, but it is not clear whether diastolic dysfunction is also reversible. With Doppler echocardiography, before and after effective therapy, we assessed the LV morphology and function of patients with acromegaly who were free of complications.

METHODS

In 15 patients with active acromegaly (age range, 33.4 +/- 9.3 years), we compared LV Doppler echocardiographic indices, before and after transsphenoidal surgery or radiotherapy or before and after both procedures, noting a significant drop in plasma levels of growth hormone (<2.0 ng/mL after oral glucose tolerance testing). Patients did not have arterial hypertension, diabetes mellitus, thyroid dysfunction, or coronary artery disease. Occasionally, in this series, patients had no symptoms of heart failure, and patients who underwent treatment with somatostatin analog drugs were not included because they did not have a significant hormonal drop. The follow-up period after hormonal control was 2.7 +/- 1.7 years. We also studied 15 healthy control subjects matched for age, sex, and body surface area.

RESULTS

Patients with acromegaly compared with healthy control subjects had increased LV mass index, relative wall thickness, and deteriorated diastolic function. After therapy, most of the abnormalities improved: LV mass index (104 +/- 21 g/m(2) x 87 +/- 21 g/m(2); P <.01), LV relative wall thickness (0.40 +/- 0.06 x 0.35 +/- 0.04; P <.01), proto/telediastolic transmitral peak flow velocity ratio (1.17 +/- 0.33 x 1.49 +/- 0.34; P <.001), and isovolumetric relaxation period (126 +/- 18 ms x 113 +/- 13 ms; P <.05).

CONCLUSION

Treatment of acromegaly in patients without clinical heart failure improves both LV morphology and diastolic function. Avoidance of progression to more advanced forms of acromegalic cardiomyopathy should be possible.

Improvement of cardiac function after treatment with octreotide followed by trans-sphenoidal surgery in an acromegalic patient who presented with congestive heart failure

Cardiovascular disease is a major cause of mortality and morbidity in patients with acromegaly. We describe the case of a 43-year-old man with acromegaly who presented with severe congestive heart failure. Treatment with the somatostatin analog octreotide improved cardiac function with an increase in left ventricular ejection fraction (LVEF) from 11% to 27%. LVEF further increased to 43% after trans-sphenoidal surgery. Recovery was uneventful. We emphasize the need for early diagnosis and effective treatment of acromegaly to prevent cardiovascular complications. Octreotide therapy or trans-sphenoidal surgery, if possible, should be considered to control cardiac function even in acromegalic patients with severe congestive heart failure.

Acromegaly: historical perspectives and current therapy

Soon after the initial description of acromegaly in the late 19th century, neurosurgeons performed the first operative procedures for the disease. Transcranial procedures eventually yielded to the transsphenoidal approach. Reasonably effective medical therapy was introduced in the 1970s and pharmacological progress continues to be realized. It is now recognized that excess growth hormone is associated with significant morbidity and mortality and that biochemical remission improves outcome. Although medical and radiation treatments offer useful adjuncts, surgery provides optimal results.

Increased arterial intima-media thickness by B-M mode echodoppler ultrasonography in acromegaly

BACKGROUND

Patients with acromegaly have an increased morbidity and mortality for cardiovascular diseases. Despite the increasing evidence for the existence of a specific cardiomyopathy in acromegaly, the presence of vascular abnormalities has been never investigated.

OBJECTIVE

To evaluate the cardiovascular risk and premature atherosclerosis in acromegaly.

SUBJECTS

Forty-five patients with acromegaly and 30 sex- and age-matched healthy subjects were included in this study: 30 patients were studied at the diagnosis of acromegaly and were in active disease (GH 59.3 +/- 10.2 mU/l, IGF-I 733 +/- 57.6 microg/l) while 15 patients were studied after surgery and/or radiotherapy and were cured from the disease (GH 4.5 +/- 0.7 mU/l, IGF-I 172.4 +/- 16.9 microg/l).

METHODS

Body mass index (BMI), systolic (SBP) and diastolic blood pressure (DBP), serum total, LDL- and HDL-cholesterol, triglycerides, and fibrinogen levels, prothrombin time (PT), activated partial thromboplastin time (APTT), glucose and insulin levels (fasting and after glucose load) were measured in all patients and controls. By echodoppler ultrasonography, blood systolic (SPV) and diastolic (DPV) peak velocity, and resistance index (RI) were measured at both common and internal carotid arteries where presence, size and location of atherosclerotic plaques were evaluated by B-Mode ultrasonography. Intima-media thickness (IMT) of both common carotids was measured by M-Mode ultrasonography.

RESULTS

SBP, but not DBP, was significantly higher in patients with active disease than in cured patients and controls (P = 0.003). Hypertension was found in nine (30%) patients with active disease, in two (13.3%) of those cured from acromegaly and in none of controls (chi2 = 10.81, P < 0.004). Fasting blood glucose levels were significantly higher both in patients with active disease and in those cured from the disease than in controls (P < 0.001). Circulating insulin levels were significantly higher in patients with active disease than in cured patients and controls (P < 0.001) and in cured patients than in controls (P < 0.001). Glucose tolerance abnormalities were found in 13 (43.3%) patients with active disease, in four (26.6%) patients with inactive disease and in four controls (13.3%) (chi2 = 6.71, P = 0.03). Total blood cholesterol levels were similar in the three groups, LDL-cholesterol and triglycerides levels were significantly higher, whereas HDL-cholesterol levels were significantly lower both in patients with active disease and in those cured from the disease than in controls (P < 0.001). Serum fibrinogen levels were significantly higher both in patients with active disease and in those cured from the disease than in controls (P < 0.001). No difference was found in PT and APTT levels among the three groups. At the level of right and left common carotid arteries, IMT was significantly higher both in patients with active disease and in those cured from the disease than in controls (P < 0.001). Both right and left SPV, but not DPV, were significantly higher in patients with active disease than in those cured from the disease and in controls (P < 0.01). Well defined carotid wall plaques were detected in two patients (6.6%) with active disease, in one patient cured from the disease (6.6%) and in two controls (6.6%). At the level of right and left internal carotid arteries, SPV, DPV and RI were similar among the three groups. Well defined carotid wall plaques were detected in three patients with active disease (10%), two patients cured from the disease (13.3%) and in one control (3.3%).

CONCLUSIONS

A significant increase of IMT of both common carotid arteries was observed in patients with active acromegaly, this was also found in those cured from acromegaly. However, the prevalence of well defined carotid plaques was not increased in both groups of patients with acromegaly as compared to controls. On this basis, heart more than vessels seems to be affected by chronic GH and IGF-I excess in acromegaly.

Growth hormone and the heart

Impaired cardiovascular function has recently been demonstrated to potentially reduce life expectancy both in GH deficiency and excess. Experimental and clinical studies have supported the evidence that GH and IGF-I are implicated in cardiac development. In most patients with acromegaly a specific cardiomyopathy, characterized by myocardial hypertrophy with interstitial fibrosis, lympho-mononuclear infiltration and areas of monocyte necrosis, results in biventricular concentric hypertrophy. In contrast, patients with childhood or adulthood-onset GH deficiency (GHD) may suffer both from structural cardiac abnormalities, such as narrowing of cardiac walls, and functional impairment, that combine to reduce diastolic filling and impair left ventricular response to peak exercise. In addition, GHD patients may have an increase in vascular intima-media thickness and a higher occurrence of atheromatous plaques, that can further aggravate the haemodynamic conditions and contribute to increased cardiovascular and cerebrovascular risk. However, several lines of evidence have suggested that the cardiovascular abnormalities can be partially reversed by suppressing GH and IGF-I levels in acromegaly or after GH replacement therapy in GHD patients. Recently, much attention has been focussed on the ability of GH to increase cardiac mass suggesting its possible use in the treatment of chronic nonendocrine heart failure. In fact, GH administration can induce an improvement in haemodynamic and clinical status in some patients. Although these data need to be confirmed in more extensive studies, such promising results seem to open new perspectives for GH treatment in humans.

Cardiovascular effects of depot long-acting somatostatin analog Sandostatin LAR in acromegaly

Cardiovascular disease is the most severe complication of acromegaly accounting for the increased mortality of these patients. Recently, the slow-release form of octreotide (OCT; Sandostatin LAR, OCT-LAR), for im injection every 28 days, was reported to induce suppression of GH levels below 7.5 mU/L (2.5 microg/L) in 39-75% of patients, and normalization of insulin-like growth factor (IGF)-I levels for age in 64-88% of patients, with an excellent patients' compliance. The aim of the present study was to investigate the early effect of OCT-LAR treatment on the left ventricular (LV) structure and performance in 15 somatostatin analog-naive patients with acromegaly (GH, 94.8 +/- 24.9 mU/L; IGF-I, 757.9 +/- 66.6 microg/L), focusing on the early effect of GH and IGF-I suppression on the heart. Cardiac structure was investigated by echocardiography, whereas LV performance was investigated by gated-blood-pool scintigraphy, before and after 3 and 6 months of treatment with OCT-LAR. OCT-LAR was initially administered im, at a dose of 20 mg every 28 days, for 3 months. In six patients, the dose was then increased to 30 mg every 28 days to achieve disease control, which was considered when fasting and/or glucose-suppressed GH values were below 7.5 and 3.0 mU/L, respectively, together with IGF-I values within the normal range for age. The treatment with OCT-LAR for 6 months induced a significant decrease of GH (to 12.9 +/- 3.0 mU/L) and IGF-I levels (to 340.3 +/- 40.2 microg/L) in all 15 patients. After 6 months of treatment, the percent IGF-I suppression was 52.8 +/- 4.4%, and serum GH/IGF-I levels were normalized in 9 patients. A significant decrease of LV mass index (LVMi), interventricular septum thickness, and LV posterior wall thickness was observed in all 15 patients after 3 and 6 months of OCT-LAR treatment: LVMi was decreased by 19.1 +/- 2.0% without any difference in patients with (19.9 +/- 2.7%) or without disease control (17.8 +/- 3.3%). Among the 11 patients with LV hypertrophy, 6 normalized their LVMi after treatment. At study entry, an inadequate LV ejection fraction (LVEF) at rest (<50%) was found in 5 patients (33.3%), whereas an impaired response of LVEF at peak exercise (<5% increase of basal value) was found in 9 patients (60%). A significant increase in LVEF, both at rest (from 51.6 +/- 2.6 to 58.1 +/- 1.7%, P < 0.01) and at peak exercise (from 51.6 +/- 2.3 to 60.2 +/- 2.4%, P < 0.001) was found in patients with (as compared with those without) disease control (from 55.2 +/- 3.8 to 58.0 +/- 4% and from 61.8 +/- 4.6 to 61.8 +/- 3.4%, respectively). Among the 5 patients with inadequate LVEF at rest, all but 1 regained a normal LVEF after 6 months of treatment; whereas, among the 9 patients with an impaired response of the LVEF at peak exercise, 3 patients normalized, 4 improved, and 2 impaired their responses after treatment. The percent of IGF-I suppression was significantly correlated with the percent increase of resting LVEF (r = 0.644, P < 0.01). Exercise duration (from 6.0 +/- 0.7 to 7.3 +/- 0.7 min) and capacity (from 69.0 +/- 8.2 to 80 +/- 7.8 watts) were increased in the 15 patients considered as a whole, but the improvement in the exercise response was significant only in patients with disease control (P < 0.01 and P < 0.05, respectively) who also had an increase in the peak ejection rate (P = 0.03). No change in hemodynamic parameters, either at rest or at peak exercise, was found after treatment with OCT-LAR in the 15 patients. In conclusion, the results of the present study demonstrate that OCT-LAR im injections every 28 days induces a sustained suppression of GH levels and IGF-I levels in all acromegalic patients, allowing achievement of disease control in 60% of patients after 6 months of treatment. The sustained suppression of IGF-I levels was followed by a significant reduction of LVMi in all patients already after 3 months of treatment, with recovery of LV hypertrophy in 6 of 11 patients. (ABSTRACT TRUN