Echocardiographic evidence for a direct effect of GH/IGF-I hypersecretion on cardiac mass and function in young acromegalics

Acromegaly: The Research and Practical Value of Noninvasive Hemodynamic Assessments via Impedance Cardiography

BACKGROUND

Arterial hypertension (AH) that accompanies acromegaly (AC) may lead to cardiovascular dysfunction. Such consequences may be detected with impedance cardiography (ICG), which is a noninvasive method of hemodynamic assessment. Early detection of subclinical hemodynamic alterations in AC patients may be crucial for optimizing treatment and preventing cardiovascular remodeling. The purpose of this study was to identify the hemodynamic parameters of the cardiovascular system that differentiate patients with AC from those in the control group (CG), with a particular emphasis on potential targets for medical therapy.

METHODS

This observational, prospective, clinical study involved a comparative analysis of 33 AC patients with no significant comorbidities and the controls selected via propensity score matching based on a set of baseline characteristics (age, sex, body mass index, mean blood pressure [MBP]), with comparable proportions of AH patients. The assessed hemodynamic parameters included the stroke volume index (SI), cardiac index, systemic vascular resistance index, velocity index (VI), acceleration index, Heather index (HI), and thoracic fluid content (TFC).

RESULTS

Both the AC group and the CG had well-controlled AH (mean blood pressure of 121/77 mmHg and 119/76 mmHg, respectively). In terms of baseline characteristics, the AC group was characterized by a higher hear rate and lower creatinine levels than the CG (76.2 bpm vs. 66.8 bpm [p = 0.001] and 0.755 mg/dL vs. 0.850 mg/dL [p = 0.035], respectively). ICG assessment of AC patients and CG patients showed the former to have higher heart rates (73.5 bpm vs. 65.2 bpm; p = 0.003), lower SI (43.8 mL/m² vs. 53.4 mL/m²; p = 0.0001), lower VI (42.1 1/1000/s vs. 49.3 1/1000/s; p = 0.037), lower HI (8.49 Ohm/s² vs. 13.4 Ohm/s², p ≤ 0.0001), and higher thoracic fluid content (TFC) (38.4 1/kOhm vs. 28.1 1/kOhm; p ≤ 0.0001), respectively.

CONCLUSIONS

Even with well-controlled hypertension, AC is associated with a high TFC, increased heart rate, and decreased indices of cardiac contractility. Hemodynamic changes in AC patients may be detected with the modern, noninvasive diagnostic tool, ICG.

ECHOCARDIOGRAPHIC MYOCARDIAL CHANGES IN ACROMEGALY: A CROSS-SECTIONAL ANALYSIS IN A TERTIARY CENTER IN BULGARIA

Context

Cardiomyopathy is the most frequent cardiovascular complication in acromegaly.

Objective

We aimed to compare some echocardiographic markers in acromegaly patients with controls and find a correlation with disease duration, disease activity, levels of growth hormone (GH) and insulin-like growth factor 1 (IGF-1).

Design

We conducted a cross-sectional case-control study for the period of 2008-2012.

Subjects and methods

Acromegaly patients altogether 146 (56 men and 90 women), were divided into four groups according to disease activity and the presence of arterial hypertension (AH). The control group included 83 subjects, matching the patient groups by age, gender and presence of AH. GH was measured by an immunofluorometric method, while IGF-1 by IRMA method. All patients and controls were subjected to one- and two-dimensional transthoracic echocardiography, color and pulse Doppler.

Results

We found a thickening of the left ventricular walls and an increase in the left ventricular mass. However, these changes were not statistically significant in all groups and no correlation with disease duration could be demonstrated. As markers of diastolic dysfunction, increased deceleration time and isovolumetric relaxation were registered, which were dependent mainly on age in a binary logistic regression analysis, but not GH or IGF-1. Using absolute values, ejection and shortening fractions were increased in some groups. Using cut-off values, a higher percentage of systolic dysfunction was demonstrated in patients compared to their corresponding controls. Engagement of the right heart ventricle was also found - increased deceleration time and decreased e/a tric ratio.

Conclusions

In conclusion, functional impairments of both ventricles were present, with a predominance of left ventricular diastolic dysfunction.

Bringing Cardiovascular Comorbidities in Acromegaly to an Update. How Should We Diagnose and Manage Them?

Patients with acromegaly frequently develop cardiovascular comorbidities, which significantly affect their morbidity and contribute to an increased all-cause mortality. In this regard, the most frequent complications that these patients may encounter include hypertension, cardiomyopathy, heart valve disease, arrhythmias, atherosclerosis, and coronary artery disease. The specific underlying mechanisms involved in the pathophysiology of these comorbidities are not always fully understood, but uncontrolled GH/IGF-I excess, age, prolonged disease duration, and coexistence of other cardio-vascular risk factors have been identified as significant influencing predisposing factors. It is important that clinicians bear in mind the potential development of cardiovascular comorbidities in acromegalic patients, in order to promptly tackle them, and avoid the progression of cardiac abnormalities. In many cases, this approach may be performed using straightforward screening tools, which will guide us for further diagnosis and management of cardiovascular complications. This article focuses on those cardiovascular comorbidities that are most frequently encountered in acromegalic patients, describes their pathophysiology, and suggests some recommendations for an early and optimal diagnosis, management and treatment.

CARDIOVASCULAR COMPLICATIONS OF ACROMEGALY

Acromegaly is associated with increased mortality and decreased life expectancy. Cardiovascular disease is the principal cause of premature mortality in patients with acromegaly, accounting for about 60% of deaths. GH and/or IGF-I exert direct cardiac effects: enhance cardiac contractility, stimulate cardiomyocyte growth, influence calcium influx in cardiomyocytes. Cardiac remodelling is influenced by hypertension and insulin resistance. Among cardiovascular risk factors arterial hypertension, reported in 35% of patients with acromegaly, ranks among most important negative prognostic factors for mortality. Hypertension plays significant role in the development of cardiac hypertrophy, especially in older acromegalic patients and diastolic blood pressure is best predictive factor for cardiac hypertrophy. Therefore, early and aggressive hypertension treatment is essential for prognosis in acromegaly. Other important risk factors are: valvular defects, arrhythmias, endothelial dysfunction, heart failure, lipid abnormalities and coronary artery disease. Numerous studies suggest that patients with acromegaly are under threat of arrhythmias, especially those with structural heart abnormalities. Congestive heart failure as end-stage acromegalic cardiomyopathy occurs usually in older patients, with long-term uncontrolled disease and other cardiovascular and metabolic complications. Relation between acromegaly and coronary artery disease is controversial as it seems to be connected rather with classical cardiovascular risk factors than GH and IGF-1 overexpresion.

Cardiovascular comorbidities in acromegaly: an update on their diagnosis and management

Comorbidities related to the cardiovascular system are one of the most prevalent in patients with acromegaly, and contribute to an increased risk of morbidity and all-cause mortality. Specifically, hypertension, cardiomyopathy, heart valve disease, arrhythmias, atherosclerosis, coronary artery disease, and cardiac dysfunction may be frequent findings. Although the underlying physiopathology for each comorbidity may not be fully elucidated, uncontrolled growth hormone/insulin-like growth factor 1 excess, age, prolonged disease duration, and coexistence of other cardio-vascular risk factors are significant influencing variables. A simple diagnostic approach to screen for the presence of these comorbidities may allow prompt treatment and arrest the progression of cardiac abnormalities. In this article, we revise the most prevalent cardiovascular comorbidities and their pathophysiology in acromegalic patients, and we address some recommendations for their prompt diagnosis, management and treatment. Strengths and pitfalls of different diagnostic techniques that are currently being used and how different treatments can affect these complications will be further discussed.

Acromegaly and associated tumours: what should gastroenterologists know?

Acromegaly is a clinical syndrome caused by the excessive production of growth hormone. It is associated with high morbidity and significantly increased mortality, mainly due to cardiovascular and respiratory complications, and cancer. Mortality is reduced to that of the general population following successful treatment, in other words, when insulin-like growth factor (IGF-I) and growth hormone values return to normal levels. Not all tumours associated with this syndrome benefit from cost-effective early diagnosis programmes. An in-depth knowledge on the part of clinicians of the morbidity and mortality associated with acromegaly, allowing them in many cases to anticipate the expected clinical course of the disease, is the best therapeutic and follow-up strategy in these patients.

Higher protein intake increases cardiac function parameters in healthy children: metabolic programming by infant nutrition-secondary analysis from a clinical trial

BACKGROUND

Protein intake may modulate cardiac structure and function in pathological conditions, but there is a lack of knowledge on potential effects in healthy infants.

METHODS

Secondary analysis of an ongoing randomized clinical trial comparing two groups of infants receiving a higher (HP) or lower (LP) protein content formula in the first year of life, and compared with an observational group of breastfed (BF) infants. Growth and dietary intake were assessed periodically from birth to 2 y. Insulin-like growth factor 1 (IGF-1) axis parameters were analyzed at 6 mo in a blood sample. At 2 y, cardiac mass and function were assessed by echocardiography.

RESULTS

HP infants (n = 50) showed a higher BMI z-score at 2 y compared with LP (n = 47) or BF (n = 44). Cardiac function parameters were increased in the HP group compared with the LP and were directly related to the protein intake during the first 6 mo of life. Moreover, there was an increase in free IGF-1 in the HP group at 6 mo.

CONCLUSION

A moderate increase in protein supply during the first year of life is associated with higher cardiac function parameters at 2 y. IGF-1 axis modifications may, at least in part, underlie these effects.

Atrial conduction times and left atrium mechanical functions in patients with active acromegaly

The aim of this study was to evaluate atrial electromechanical delay (EMD), P wave dispersion (Pwd), and left atrial (LA) mechanical functions in patients with active acromegaly. Twenty-three patients with active acromegaly and 27 age- and sex-matched controls were included in this study. All atrial electromechanical interval parameters (PA lateral, PA septum, PA tricuspid, interatrial EMD, intra-LA EMD, and intra-right atrial EMD) were measured from mitral lateral annulus, mitral septal annulus, and right ventricular tricuspid annulus by tissue Doppler imaging. LA volumes were measured by the disk method in the apical four-chamber view and were indexed to the body surface area. Mechanical function parameters of LA were calculated. Pwd was performed by 12-lead electrocardiograms. Atrial electromechanical intervals (PA lateral, PA septum, PA tricuspid, interatrial EMD, intra-LA EMD, and intra-right atrial EMD) and Pwd were similar between patients with acromegaly and control subjects (all p > 0.05). LA volumes (maximum, minimum, and presystolic) and LA mechanical functions were not significantly different between the groups (all p > 0.05). Additionally, serum levels of growth hormone and insulin-like growth factor-1 were not correlated with atrial electromechanical parameters and LA mechanical functions. Atrial electrical conduction times were not prolonged and LA mechanical functions were not impaired in patients with active acromegaly compared with controls. And the prevalence of supraventricular arrhythmia risk may not increase in this population.

Quantifying subtle changes in cardiovascular mechanics in acromegaly: a Doppler myocardial imaging study

AIM OF THE STUDY

To describe morphological and functional cardiovascular changes in acromegaly (ACM) patients, as well as to investigate the ability of Doppler-based myocardial deformation imaging (DMI) to characterize subtle dysfunction in ACM.

METHODS

69 patients (pts) with ACM (mean age 47 ± 10 years, 27 men) and 31 controls (mean age 43 ± 16 years, matched for age and gender) were recruited. Standard echocardiography and DMI data were obtained for all patients. Peak systolic longitudinal strain values (S) were determined for the left and right ventricles. Radial S was measured at the level of the mid inferolateral segment. Using a high-resolution echo-tracking system, the main indices of arterial stiffness were measured.

RESULTS

Of the ACM subjects, 57 had active disease (group A), and 12 controlled ACM (group B). All pts with ACM presented structural changes: a higher LV indexed mass (112 ± 36, 118 ± 23 vs 74 ± 18 g/m(2), p < 0.001) and a higher relative wall thickness (0.45 ± 0.09, 0.50 ± 0.07 vs 0.40 ± 0.07, p = 0.003) compared to controls. Also, ACM pts had functional changes: reduced LV ejection fraction (57 ± 5, 55 ± 5 vs 64 ± 4%, p < 0.001) and altered diastolic function (E/A 1.0 ± 0.4, 1.1 ± 0.1 vs 1.3 ± 0.3, p = 0.005) compared to controls. Both longitudinal and radial LV S values were lower in ACM compared to controls: -16.5 ± 3.5, -16.8 ± 4.3 vs -21.5 ± 3.8%, p < 0.001 for longitudinal and 38.3 ± 12.3, 35.6 ± 11.8 vs 52.2 ± 11.7%, p = 0.002 for radial strain.

CONCLUSIONS

ACM pts present LV concentric hypertrophy and LV systolic and diastolic dysfunction, even in controlled disease. Altered global LV systolic function appears to be due both to longitudinal and radial dysfunction.

Left ventricular synchronicity is impaired in patients with active acromegaly

Acromegaly is associated with a variety of cardiovascular disturbances such as left ventricular hypertrophy, diastolic cardiac dysfunction, and hypertension. Left ventricular (LV) dyssynchrony means the impairment of synchronicity and is defined as the loss of the simultaneous peak contraction of corresponding cardiac segments. The objective of this study was to investigate whether acromegalic patients have left ventricular dyssynchrony. Dyssynchrony was evaluated in 30 patients with active acromegaly and 30 controls. All the patients and controls were subjected to a tissue synchronization imaging. The time to regional peak systolic tissue velocity (Ts) in LV by the six-basal-six-mid-segmental model was measured on ejection phase TSI images and four TSI parameters of systolic dyssynchrony were computed. All TSI parameters of LV dyssynchrony increased in patients with acromegaly compared to the controls: the standard deviation (SD) of the 12 LV segments Ts (43.5 ± 13.5 vs 26.2 ± 12.5, p < 0.001); the maximal difference in Ts between any 2 of the 12 LV segments (133.3 ± 38 vs 84.6 ± 37.6, p < 0.001); the SD of the 6 basal LV segments (41.1 ± 15.9 vs 25.4 ± 14.8, p = 0.001); and the maximal difference in Ts between any 2 of the 6 basal LV segments (102.6 ± 37.5 vs 65.2 ± 36.9, p = 0.001). In addition, there were significant relationships between the levels of growth hormone/insulin-like growth factor-1 and Ts-SD-12. LV synchronicity has been impaired in patients with acromegaly. Left ventricular dyssynchrony is associated with disease activity and it may contribute to the harmful cardiovascular effects of acromegaly.

Congestive heart failure in acromegaly: A review of 6 cases

BACKGROUND

Though cardiac involvement is common in acromegaly, overt congestive heart failure is uncommon.

MATERIALS AND METHODS

This is retrospective analysis of hospital record between 1996 and 2007. We analyzed records of 150 consecutive patients with acromegaly. We included the patients with acromegaly those who had overt congestive heart failure either at presentation or during the course of illness for the present analysis. The diagnosis of acromegaly and congestive cardiac failure were based on standard criteria.

RESULTS

Out of 150 patients with acromegaly, 6 patients had overt CHF (4.0%), of which 4 presented with the features of CHF and 2 developed during the course of illness. Three patients had hypertension and 1 had diabetes. Baseline echocardiography showed severe biventricular dysfunction and global hypokinesia in all. Angiography showed dilated hypokinetic left ventricle with normal coronaries in 3, it was confirmed at autopsy in 1. Three underwent trans-sphenoidal surgery, 1 received somatostatin analogue as primary treatment modality. Normalization of growth hormone and IGF-1 led to improvement in cardiac function in 1, 1 patient lost to follow up, and 4 died during the course of illness. In 1 patient, autopsy was performed and cardiac specimen revealed normal coronaries, concentric ventricular hypertrophy, and dilatation with myofibrolysis and interfascicular fibrosis.

CONCLUSION

Prevalence of overt CHF is 4% in present series. Overt CHF carries poor prognosis and hence, this complication should be recognized at earliest, and medical management to normalized cardiac function should be given utmost priority.

Growth hormone and the cardiovascular system

Growth hormone (GH) exerts its effects through insulin-like growth factor-1, and although ubiquitous in human tissues, it has a significant role in cardiovascular function. In recent years, there has been a great deal of interest in GH as an etiologic factor in many cardiovascular disease states. Acromegaly, a state of endogenous GH excess, results in myocardial hypertrophy and decreased cardiac performance with increased cardiovascular mortality. Additional insight into the role of excess GH on the cardiovascular system has been gained from data collected in athletes doping with GH. Likewise, GH deficiency is associated with increased mortality, possibly from the associated increase in atherosclerosis, lipid abnormalities, and endothelial dysfunction. However, further research is required to clarify the benefit of GH treatment in both deficient states and in heart failure patients.

Determinants of cardiac disease in newly diagnosed patients with acromegaly: results of a 10 year survey study

CONTEXT

The most frequent cause of death in acromegaly is cardiomyopathy.

OBJECTIVE

To evaluate determinants of acromegalic cardiomyopathy.

DESIGN

Observational, open, controlled, retrospective study.

SUBJECTS

Two hundred and five patients with newly diagnosed active acromegaly (108 women and 97 men; median age 44 years) and 410 non-acromegalic subjects sex- and age-matched with the patients.

MAIN OUTCOME MEASURES

Left ventricular (LV) mass index (LVMi), transmitral inflow early-to-atrial (E/A) peak velocity ratio, and LV ejection fraction (LVEF) were measured by Doppler echocardiography to determine the prevalence of LV hypertrophy (LVH), diastolic and systolic dysfunction. The role of age, estimated disease duration, body mass index, GH and IGF1 levels, systolic and diastolic blood pressure, lipid profile and glucose tolerance in determining different features of the acromegalic cardiomyopathy was investigated.

RESULTS

Compared with controls, the patients had lower E/A, LVEF, high-density lipoprotein (HDL)-cholesterol levels and higher LVMi, total- and low-density lipoprotein (LDL)-cholesterol, triglycerides, glucose and insulin levels, homeostatic model assessment of insulin resistance (HOMA-R) and HOMA-β. The relative risk to develop mild (odds ratio (OR)=1.67 (1.05-2.66); P=0.027) or severe hypertension (OR=1.58 (1.04-2.32); P=0.027), arrhythmias (OR=4.93 (1.74-15.9); P=0.001), impaired fasting glucose/impaired glucose tolerance (OR=2.65 (1.70-4.13); P<0.0001), diabetes (OR=2.14 (1.34-3.40); P=0.0009), LVH (OR=11.9 (7.4-19.5); P<0.0001), diastolic (OR=3.32 (2.09-5.31); P<0.0001) and systolic dysfunction (OR=14.2 (6.95-32.2); P<0.0001), was higher in acromegaly. The most important predictor of LVH (t=2.4, P=0.02) and systolic dysfunction (t=-2.77, P=0.006) was disease duration and that of diastolic dysfunction was patient's age (t=-3.3, P=0.001). Patients with an estimated disease duration of >10 years had a relative risk to present cardiac complications three times higher than patients with estimated disease duration ≤5 years.

CONCLUSIONS

The prevalence of different features of cardiomyopathy is 3.3-14.2 times higher in the acromegalic than in the non-acromegalic population. The major determinant of cardiomyopathy is disease duration.

Hypertension-related factors in patients with active and inactive acromegaly

INTRODUCTION: There are several complications of the cardiovascular system caused by acromegaly, especially hypertension. OBJECTIVES: To evaluate hypertension characteristics in patients with cured/controlled acromegaly and with the active disease. PATIENTS AND METHODS: Cross-sectional study of the follow-up of forty-four patients with acromegaly submitted to clinical evaluation, laboratory tests and cardiac ultrasound. Patients with cured and controlled disease were evaluated as one group, and individuals with active disease as second one. RESULTS: Forty-seven percent of the patients had active acromegaly, and these patients were younger and had lower blood pressure levels than subjects with controlled/cured disease. Hypertension was detected in 50% of patients. Subjects with active disease showed a positive correlation between IGF-1 and systolic and diastolic blood pressure levels (r = 0.48, p = 0.03; and r = 0.42, p = 0.07, respectively), and a positive correlation between IGF-1 and urinary albumin excretion (UAE) rates. In patients with active disease, IGF-1 was a predictor of systolic blood pressure, although it was not independent of UAE rate. For individuals with cured/controlled disease, waist circumference and triglycerides were the predictors associated with systolic and diastolic blood pressure. CONCLUSIONS: Our findings suggest that blood pressure levels in patients with active acromegaly are very similar, and depend on excess GH. However, once the disease becomes controlled and IGF-1 levels decrease, their blood pressure levels will depend on the other cardiovascular risk factors.

Growth hormone status predicts left ventricular mass in patients after cure of acromegaly

CONTEXT

Growth hormone excess and growth hormone deficiency (GHD) are both associated with increased cardiovascular morbidity. A specific acromegaly-related cardiomyopathy has been described, characterized in part by increased left ventricular mass (LVM). Growth hormone deficiency is associated with reduced LVM. Following cure of acromegaly with surgery or radiation therapy, GHD may develop; however, its effects on cardiac morphology and function in this population are not established.

OBJECTIVE

We hypothesized that the development of GHD in patients with prior acromegaly would be associated with cardiac morphologic and functional changes that differ from those in patients who are GH sufficient following cure of acromegaly.

DESIGN

A cross-sectional study was conducted in a Clinical Research Center. Study participants consisted of three groups of subjects (n=34): I. Cured acromegaly with GHD (n=15), II. Cured acromegaly with GH sufficiency (n=8), and III. Active acromegaly (n=11). Main outcome measures included cardiac morphology and function, using echocardiography parameters.

RESULTS

Mean age and BMI, 44.6 ± 2.3 years (SEM) and 30.7 ± 1.3 kg/m², respectively, were not different among the three groups. Mean peak GH values were: I. 2.8 ± 0.4 ng/ml; II. 30.1 ± 9.1 ng/ml (p=0.0002.) In group I, left ventricular mass, indexed to body surface area (LVMi), was within the normal range in all patients; moreover, left ventricular (LV) geometry was normal. At least 50% of patients in groups II and III had elevated LVMi, and in 50% of patients, LV geometry was abnormal, indicating pathologic hypertrophy. Ejection fraction was similar between all three groups. There were no significant differences in diastolic function.

CONCLUSIONS

Patients who develop GHD following cure of acromegaly do not demonstrate elevated LV mass, in contrast to patients with a history of acromegaly but normal GH levels or to patients with active acromegaly. This suggests that GH status after treatment of acromegaly correlates with LV mass, and that, in GH sufficient patients, reversal of remodeling may be slower than previously thought. These data suggest that it will be important to determine whether GH replacement alters left ventricular morphology over time.

Distúrbios cardiovasculares na acromegalia

A acromegalia acarreta uma série de distúrbios ao sistema cardiovascular, decorrentes da exposição crônica a níveis elevados de GH e IGF-1. Estes distúrbios são os principais responsáveis pelo aumento da mortalidade de acromegálicos. Entre as várias formas de acometimento cardiovascular, destaca-se a miocardiopatia acromegálica, entidade caracterizada, inicialmente, pelo estado hiperdinâmico, seguido de hipertrofia ventricular esquerda concêntrica e disfunção diastólica por déficit de relaxamento, culminando com disfunção sistólica e, por vezes, insuficiência cardíaca franca. Além disso, são também relevantes as arritmias, as valvulopatias, sobretudo mitral e aórtica, a cardiopatia isquêmica, a hipertensão e os distúrbios dos metabolismos glicêmico e lipídico. Nesta revisão são abordados os principais aspectos clínicos e prognósticos destas entidades, os efeitos do tratamento da acromegalia sobre elas e as repercussões correspondentes sobre a sobrevida dos pacientes.

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.

Amelioration of cardiovascular risk factors with partial biochemical control of acromegaly

OBJECTIVE

Complete remission of acromegaly is associated with favourable changes in cardiovascular risk parameters. We evaluated the effects of suboptimal therapy on haemodynamic, metabolic, inflammatory and coagulation cardiovascular risk indices.

DESIGN AND METHODS

Eighteen acromegalic patients on somatostatin analogues, with incomplete biochemical control, were evaluated at diagnosis and 6 months after treatment and compared to 15 healthy age- and body mass index (BMI)-matched controls. Measurements of blood pressure, GH, IGF-I, glucose, insulin, glycated haemoglobin (HbA1c), lipids, apolipoprotein A1 (apoA1), apoB, high-sensitivity C-reactive protein (hs-CRP), fibrinogen, plasminogen activator inhibitor 1 (PAI-1), tissue plasminogen activator (tPA) and circulating thrombomodulin were performed in all study participants, followed by an oral glucose tolerance test (OGTT). Insulin sensitivity (IS) was expressed by the Matsuda index (OGTT(ISI)).

RESULTS

Partial control of acromegaly resulted in a significant reduction in systolic and diastolic blood pressure, glucose, insulin, HbA1c, total (T-C) and low density lipoprotein cholesterol (LDL-C) and triglyceride levels, and a significant increase in apoA1, high density lipoprotein cholesterol (HDL-C) and OGTT(ISI) compared to pretreatment levels. Plasma fibrinogen and PAI-1 levels fell significantly [respectively (mean +/- SEM), 11.04 +/- 0.41 vs. 10.12 +/- 0.34 micromol/l, P = 0.003 and 9.6 +/- 1.97 vs. 6.55 +/- 1.89 microg/l, P < 0.001]. However, a marked reduction in tPA [median (IQR) 5.1 (2.5-15) vs. 3.4 (2.4-8.6) microg/l, P = 0.031] and an increase in hs-CRP [median (IQR) 0.05 (0.03-0.11) vs. 0.1 (0.06-0.23) mg/l, P < 0.001] were also noted. On treatment, acromegalic patients were comparable to controls, except for OGTT(ISI), lipoprotein(a) [Lp(a)], fibrinogen and tPA and HDL-C levels. Thrombomodulin and apoB levels were not affected by treatment.

CONCLUSIONS

Partial control in disease activity following somatostatin analogues results in significant improvement in a considerable number of cardiovascular risk markers in acromegaly.

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.

Current diagnosis of acromegaly

Acromegaly is a rare and chronic condition that is characterized by sustained unregulated hypersecretion of growth hormone (GH). More than 99% of the cases of acromegaly are due to a pathologic proliferation of pituitary somatotrophs presenting in the form of a pituitary adenoma. The excessive amounts of GH and its target hormone, insulin like growth factor-1 (IGF-1) cause metabolic changes and tissue enlargement that, collectively, lead to significant morbidity and a two to threefold increase in mortality. Thus, early diagnosis has proved to be crucial to improve survival and quality of life in this condition. The development of radioimmunoassay (RIA) in the 1960s provided clinicians with a biochemical tool to diagnose acromegaly. Many limitations were inherent to this methodology which necessitated the development of more sensitive tools, such as immunoradiometric (IRMA) or immunoluminometric (ILMA) assays for GH and IGF-1 measurements. These newer assays have not come without imperfections. The reference ranges to describe normalcy of the somatotropic axis and the biochemical criteria of "cure" of acromegaly are areas of great debate. Nevertheless, the current international consensus agrees that the diagnosis of acromegaly should be based on both clinical presentation and biochemical data.

High prevalence of cardiac hypertophy without detectable signs of fibrosis in patients with untreated active acromegaly: an in vivo study using magnetic resonance imaging

OBJECTIVE

Left ventricular (LV) hypertrophy and myocardial fibrosis are considered the main pathological features of acromegalic cardiomyopathy. The aim of the study was to evaluate the proportion of LV hypertrophy and the presence of fibrosis in acromegalic cardiomyopathy in vivo using cardiac magnetic resonance (CMR).

DESIGN AND PATIENTS

Fourteen consecutive patients (eight women, mean age 46 +/- 10 years) with untreated active acromegaly were submitted to two-dimensional (2D) colour Doppler and integrated backscatter (IBS) echocardiography and CMR.

MEASUREMENTS

LV volume, mass and wall thickness and myocardial tissue characterization (IBS and CMR).

RESULTS

On echocardiography: mean LV mass (LVM) and LVM index (LVMi) were 209 +/- 48 g and 110 +/- 24 g/m(2), respectively; hypertrophy was revealed in five patients (36%); abnormal diastolic function [evaluated by isovolumic relaxation time (IVRT) or early (E) to late or atrial (A) peak velocities (E/A ratio)] was found in four patients (29%). Systolic function evaluated by measuring LV ejection fraction (LVEF) was normal (mean 72 +/- 12%) in all patients. Six patients (43%) had increased IBS (mean 57.4 +/- 6.2%). On CMR: mean LVM and LVMi were 151 +/- 17 g and 76 +/- 9 g/m(2), respectively; 10 patients (72%) had LV hypertrophy. Contrastographic delayed hyperenhancement was absent in all patients; on the contrary, mild enhancement was revealed in one patient. Systolic function was normal in all patients (LVEF 67 +/- 11%). LVMi was not related to serum IGF-1 concentrations or the estimated duration of disease.

CONCLUSIONS

CMR is considered to be the gold standard for evaluating cardiac hypertrophy, fibrosis and systolic function. Using CMR, 72% patients with untreated active acromegaly had LV hypertrophy, which was only detected in 36% patients by echocardiography. However, cardiac fibrosis was absent in all patients irrespective of the estimated duration of disease. Although a very small increase in collagen content (as suggested by increased cardiac reflectivity at IBS), not detectable by CMR, could not be ruled out, it is unlikely that it would significantly affect cardiac function.

Assessment of the Tei index by tissue Doppler imaging in patients with acromegaly: serum growth hormone level is associated with the Tei index

BACKGROUND

The Tei index reflects both systolic and diastolic ventricular function. The aim of this study was to assess the Tei index by tissue Doppler imaging (TDI) and also to evaluate the correlation with growth hormone (GH) and the Tei index and left ventricular (LV) function assessed by TDI in patients with acromegaly.

METHODS

We prospectively evaluated 25 patients with acromegaly and 27 control subjects. LV systolic and diastolic function was assessed by conventional echocardiography and TDI.

RESULTS

Peak E velocity and E/A ratio were lower in those with acromegaly than in those without (P = 0.01; P = 0.002, respectively). Deceleration time of the mitral E-wave (P = 0.01) and isovolumic relaxation time (IVRT) (P = 0.01) were higher in acromegalic patients than those in controls (P = 0.006, P = 0.002). Em (P = 0.01) and Em/Am (P = 0.001) were lower in patients with acromegaly than in controls. In patients with acromegaly, the Tei index was significantly higher than that in controls (0.49 +/- 13.4 vs 0.39 +/- 5.2, P = 0.005). GH was positively correlated with the Tei index (r = 0.65, P = 0.041), Em/Am (r = 0.63, P = 0.021), and interventricular septum (IVS) thickness (r = 0.65, P = 0.008) only in patients with acromegaly. LV diastolic dysfunction was detected 36% by conventional echocardiography and 48% by the Tei index derived from TDI in acromegalic patients.

CONCLUSION

TDI analysis of mitral annular velocities is useful to assess LV diastolic dysfunction in patients with acromegaly. GH was positively correlated with the Tei index and LV diastolic dysfunction. The Tei index may be superior to conventional mitral Doppler indices for identification of LV diastolic dysfunction in patients with acromegaly.

Risk factors for development of coronary heart disease in patients with acromegaly: a five-year prospective study

BACKGROUND

Data on coronary heart disease (CHD) are scanty and matter of argument in acromegalic patients.

OBJECTIVE

The objective of this study was to evaluate risk factors for development of CHD and the occurrence of cardiac events in acromegalic patients during a 5-yr prospective study.

DESIGN

Ten-year likelihood for CHD development was estimated by the Framingham scoring system (FS); patients were stratified as having low (FS < 10), intermediate (>or= 10 FS < 20), or high (FS >or= 20) risk. Coronary artery calcium content was measured using the Agatston score (AS) in all patients; those with positive AS were submitted to myocardial single-photon emission computed tomography; cardiac events were recorded during a 5-yr follow-up period.

PATIENTS

Fifty-two consecutive patients (31 women, mean age 52 +/- 11 yr) with controlled or uncontrolled acromegaly were followed prospectively for 5 yr.

RESULTS

Thirty-seven patients (71%) had low, 14 patients (27%) had intermediate, and one patient (2%) had high CHD risk. CHD risk was unrelated to acromegaly activity or the estimated duration of disease. Among patients with FS less than 10%, 24 had AS equal to 0, eight had AS of 1 or greater and less than 100, and five had AS 100 or greater and less than 300, respectively. Among patients with FS 10 or greater and less than 20%, nine had AS equal to 0, two had AS of one or greater and less than 100, one had AS of 100 or greater and less than 300, and two had AS of 300 or greater; a patient of the latter group, having AS of 400 or greater, increased his CHD risk from 11% to 20% or more. FS or AS did not differ in patients with controlled or uncontrolled acromegaly (P = 0.981). All patients with positive AS had no single photon emission computed tomography perfusion defects. During the 5-yr follow-up period no patient developed ischemic cardiac events.

CONCLUSIONS

CHD risk in acromegalic patients, predicted by FS as in nonacromegalic subjects, is low; AS might have adjunctive role only in a subset of patients. However, most patients have systemic complications of acromegaly, which participate in the assessment of global CHD risk.

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.

Myocardial systolic strain abnormalities in patients with acromegaly: a prospective color Doppler imaging study

BACKGROUND

Heart abnormalities are frequent findings in patients with acromegaly: systolic abnormalities are considered to be secondary to diastolic changes.

AIM

The aim of the study was to evaluate whether early systolic abnormalities might be revealed in acromegalic patients using the high sensitive color Doppler myocardial imaging (CDMI) technique.

PATIENTS AND METHODS

Twenty-two consecutive acromegalic patients with active untreated disease (ACROUNTR) were evaluated at baseline and after a 6-month course with SS analogs (SSa) (ACROSSa); 25 healthy subjects served as controls. All subjects underwent conventional 2D-color Doppler echocardiography, pulse wave tissue Doppler imaging (PW-TDI) and CDMI.

RESULTS

Mean left ventricular (LV) ejection fraction did not differ in ACROUNTR and in controls; at variance, ACROUNTR patients had reduced mean LV diastolic function (E/A ratio: 0.96+/-0.3 vs controls: 1.6+/-0.3; p<0.002). Impairment of global LV diastolic function was confirmed by PW-TDI in ACROUNTR patients having a normal systolic function. Regional myocardial systolic strain (epsilon) and strain rate (SR) values, indices of regional systolic heart deformation, were lower in ACROUNTR [epsilonsys (S) -19.8+/-2.9 and epsilonsys (L): -17.7+/-2.2] than in controls [epsilonsys (S): -27.9+/-3.8; p<0.001 and epsilonsys (L): -25.3+/-2.6; p<0.001]. In addition, the early phase of diastolic function, evaluated using SR parameters, was impaired in acromegalic patients (p<0.005 vs controls). Strain and SR values were related to serum GH and IGF-I levels (p<0.02) and greatly improved after a 6-month course with SSa [epsilonsys (S) improved to -23.8+/-3.8 (p<0.05) and epsilonsys (L) improved to -24.7+/-2.4 (p<0.03)].

CONCLUSIONS

Our study confirms that ACROUNTR patients have impaired diastolic function. More important, our study clearly shows that ACROUNTR patients have an impairment of regional myocardial systolic function, which is not secondary to diastolic changes. These intramyocardial functional abnormalities improved during medical treatment of acromegaly. It is conceivable that GH-IGF-I excess has detrimental effects either on the diastolic or the systolic phases of heart function.

[Cardiac morphology and performance alterations and analysis of determinant factors of left ventricular hypertrophy in 40 patients with acromegaly]

Acromegaly has a high mortality rate due mainly to cardiovascular complications. The aim was to evaluate the determinant factors of left ventricular hypertrophy (LVH) and cardiac alterations in 40 acromegalic patients submitted to clinical-laboratorial studies and echocardiogram. The variables analyzed were age, sex, disease duration, arterial hypertension (AH), impaired glucose tolerance/DM, previous treatment with octreotide, GH and %IGF-I. Univaried analysis showed that patients with LVH were older (p= 0.031), had higher prevalence of AH (p= 0.009) and higher %IGF-I (p= 0.002), than those without LVH. Multivaried analysis showed AH and %IGF-I as determinants of LVH (p= 0.035 and p= 0.016). After dichotomizing of %IGF-I, a score was created and the frequency of LVH was 9%, 65%, 92% x 0, 1, 2; p< 0.0001. Prevalence of aortic ectasia was higher and valvar disease was smaller than reported in the literature. We conclude that AH and %IGF-I were determinants of LVH.

Uncontrolled acromegaly is associated with progressive mitral valvular regurgitation

INTRODUCTION

Recent cross-sectional studies have documented an association between acromegaly and regurgitant valvular heart disease. The aim of this study was to evaluate the change in prevalence of valvular heart disease in relation to the clinical activity, because the natural history of valvular changes in acromegaly is unknown.

PATIENTS AND METHODS

Valvular regurgitation was assessed in 37 acromegalic patients (18 patients with active disease, and 19 with controlled disease) by conventional two-dimensional and Doppler echocardiography before and after an interval of 1.9 years (range 1.5-3.0 years).

RESULTS

At baseline, valvular regurgitation (mitral and aortic sites combined) was present in 46% of the patients and increased to 67% at follow-up (P=0.008). Mitral regurgitation increased significantly from 32% to 60% (P=0.002), but no change was noted for the aortic valve (27% vs. 31%, NS). In patients with active disease, valvular regurgitation increased significantly from 56% at baseline to 88% at follow-up (P=0.031) due to a significant increase of mitral regurgitation from 39% to 78% at follow-up (P=0.016). In contrast, no increase in valvular regurgitation was found in patients with controlled disease.

CONCLUSION

The prevalence of mitral, but not aortic, valvular regurgitation increased in patients with active acromegaly during follow-up. Patients with acromegaly require adequate cardiac evaluation and follow-up to establish the extent and progression of valvular involvement.

[Acromegaly in elderly people]

Acromegaly is associated with increased morbidity and mortality. Cardiovascular complications are the major predictors of mortality. Age and duration of symptoms are the major determinants of acromegalic cardiopathy. Successful control of acromegaly reverse cardiovascular abnormalities. Herein, we review clinical, biological and histopathological findings in elderly people. Treatments and side effects in relation with aging are questioned.

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.

Improvement of intrinsic myocardial contractility and cardiac fibrosis degree in acromegalic patients treated with somatostatin analogues: a prospective study

BACKGROUND

Acromegalic patients have increased left ventricular (LV) mass (M) and impaired diastolic function.

AIM

Using ultrasonic cardiac tissue characterization, we evaluated the early changes in cardiac fibrosis (IBS) and intrinsic myocardial contractility (CVI) as well as their reversibility after treatment with somatostatin analogues (SMSA) in patients with acromegaly.

PATIENTS AND METHODS

Twenty-two acromegalic patients with active untreated disease (Acro(UNTR)) underwent conventional Doppler echocardiography and integrated backscattering; 25 healthy subjects (controls) and eight patients with acromegaly in remission after pituitary adenomectomy (Acro(REM)) served as controls.

RESULTS

As expected, Acro(UNTR) at baseline had higher LVM than controls or Acro(REM) (P < 0.001); LVM reduced in acromegalic patients after SMSA (P < 0.005 vs. baseline) while LV ejection fraction did not change. LV diastolic function was reduced in all acromegalic patients, either at baseline or after SMSA therapy (E/A ratio, 0.96 +/- 0.3 and 1.1 +/- 0.3, respectively, P < 0.002 vs. controls, 1.6 +/- 0.3). CVI was reduced in Acro(UNTR) (14.3 +/- 5.8%, P < 0.003 vs. controls, 28.7 +/- 7.5%) and greatly improved after SMSA (22.5 +/- 4.5%, P < 0.003 vs. baseline). Cardiac fibrosis was increased in Acro(UNTR) (IBS(MSI), 53.7 +/- 5.3%P < 0.002 vs. controls) and reduced after SMSA (43.7 +/- 4.2%P < 0.002 vs. baseline) albeit not reaching values observed in controls. More importantly, five of 22 (23%) Acro(UNTR) patients had normal LVM, but increased cardiac fibrosis as revealed by back scattering. IBS values and CVI% were related with serum GH and IGF-1 (P < 0.0001) levels, and the estimated duration of disease (P < 0.005).

CONCLUSIONS

The present study demonstrated that active acromegalic patients had early impairment of systolic function and increased cardiac fibrosis; increased fibrosis may precede LV hypertrophy; these changes are related to the activity of disease and might improve during treatment with SMSA.

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.

Cardiovascular function in acromegaly

Even with modern treatment, acromegaly is associated with a 2- to 3-fold increase in mortality, mainly from vascular disease, which is probably a result of the long exposure of tissues to excess GH before diagnosis and treatment. There is accumulating evidence that effective treatment to lower serum GH levels to less than 1-2 ng/ml (glucose suppressed or random, respectively) and normalize IGF-I improves long-term outcome and survival. In addition to recognized cardiovascular risk factors of hypertension, type 2 diabetes mellitus, and dyslipidemia, there is accumulating evidence of specific structural and functional changes in the heart in acromegaly. Along with endothelial dysfunction, these changes may contribute to the increased mortality in this disease. There are specific structural changes in the myocardium with increased myocyte size and interstitial fibrosis of both ventricles. Left ventricular hypertrophy is common even in young patients with short duration of disease. Some of these structural changes can be reversed by effective treatment. Functionally, the main consequence of these changes is impaired left ventricular diastolic function, particularly when exercising, such that exercise tolerance is reduced. Diastolic function improves with treatment, but the effect on exercise tolerance is more variable, and more longitudinal data are required to assess the benefits. What scant data there are on rhythm changes suggest an increase in complex ventricular arrhythmias, possibly as a result of the disordered left ventricular architecture. The functional consequences of these changes are unclear, but they may provide a useful early marker for the ventricular remodeling that occurs in the acromegalic heart. Endothelial dysfunction, especially flow-mediated dilatation, is an early marker of atherosclerosis, and limited data imply that this is impaired in active acromegaly and can be improved with treatment. Similarly, early arterial structural changes, such as thickened intima media layer, appear more common in acromegalics, and there are hints that this may diminish with effective treatment, although more studies are required for a definite conclusion on this topic. In conclusion, impaired cardiac and endothelial structure and function in acromegaly are risk factors for vascular mortality and should be regarded as legitimate therapeutic targets in the overall management of this condition.

Primary medical therapy for acromegaly

There is now considerable evidence that the clinical outcome in patients with acromegaly can be improved very substantially by means of better surgical expertise and effective medical therapies used in a flexible and innovative manner. Medical therapy alone in patients who have not undergone surgery or radiotherapy (primary medical therapy) offers the prospect of near normalisation of GH/IGF-I levels together with substantial tumour shrinkage in a significant number of 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.

Pituitary tumor endocrinopathies and their endocrine evaluation

Pituitary tumors, depending on their respective cell type, manifest various endocrinopathies. Prolactinomas may present as hypogonadism and galactorrhea and can be diagnosed by measuring morning prolactin levels. Gonadotropinomas rarely cause gonadal hyperstimulation, and dynamic thyrotropin-releasing hormone stimulation testing is often required to elicit a diagnostic gonadotropin and/or subunit secretory response. Acromegaly is a multisystemic debilitating disease for which early diagnosis and treatment are crucial. Diagnostic criteria include a lack of plasma growth hormone suppression during the oral glucose tolerance test and elevation of age- and sex-matched insulin growth factor-1 levels. Patients harboring corticotropin-secreting adenomas characheristically present with signs and symptoms of hypercortisolism. Inferior petrosal sinus sampling for corticotropin may be required for microadenoma localization. Thyrotropinomas produce inappropriate thyrotropin (TSH) secretion and hyperthyroidism. The new third-generation TSH assay has improved the rate of detection of these lesions at an earlier stage.

Impact of disease activity on left ventricular performance in patients with acromegaly

BACKGROUND

In patients with acromegaly, abnormalities of systolic and diastolic left ventricular (LV) performance, mostly associated with hypertension or LV hypertrophy, have been reported. We used 2-dimensional/Doppler echocardiographic methods and tissue Doppler imaging (TDI) to elucidate the impact of disease activity on LV function in patients with acromegaly.

METHODS

In a prospective study design, 15 patients with active acromegaly (AA group; mean age-adjusted serum insuline-like growth factor-I [IGF-I] level, 420 +/- 170 ng/mL, mean growth hormone nadir during 75-g oral glucose load, 12.3 +/- 30.1 microg/L), 18 patients with cured (n = 14, mean IGF-I level 205 +/- 115 ng/mL, mean growth hormone nadir during glucose load 0.72 +/- 0.34 microg/L) or well-controlled (n = 4, normal age-adjusted ranges of IGF-I levels with medication with somatostatin analogues 354 +/- 88 ng/mL) acromegaly (CA group), and 24 control subjects (control group) underwent 2-dimensional/Doppler echocardiographic measurements, including assessment of the Tei index (isovolumic contraction time and isovolumic relaxation time divided by ejection time). Systolic and diastolic mitral annular velocities (peak systolic velocity, peak early diastolic velocity [E'], peak late diastolic velocity [A'], E'/A' ratio) were derived from pulsed TDI.

RESULTS

No significant differences between study groups were observed with respect to muscle mass and systolic parameters, such as ejection fraction, fractional shortening, and peak systolic velocity. In patients with AA, E' and the E'/A' ratio were lower than in control and CA subjects (AA 6.8 +/- 1.7 cm/s, control 10.0 +/- 1.7 cm/s, CA 9.1+/- 3.0 cm/s, P <.01 AA vs control, P <.05 AA versus CA, AA 0.68 +/- 0.22, control 0.98 +/- 0.16, CA 0.89 +/- 0.37, P <.01 AA vs control and CA, respectively). In comparison with control subjects and patients with CA, patients with AA had a reduced mitral peak velocity of early/late filling ratio (AA 0.78 +/- 0.22 m/s, control 1.12 +/- 0.33 m/s, CA 1.11 +/- 0.36 m/s, P <.05 AA vs control and CA) and a prolonged deceleration time (AA 223 +/- 41 ms, control 188 +/- 26 ms, CA 185 +/- 25 ms, P <.05 AA vs control and CA). The Tei index was significantly elevated in patients with AA in comparison with control subjects and patients with CA (AA 0.54 +/- 0.13, control 0.40 +/- 0.09, CA 0.44 +/- 0.10, P <.05 AA vs control and CA). No significant differences were observed between control subjects and patients with CA with respect to mitral flow-derived variables, TDI parameters, and the Tei index.

CONCLUSION

Disease activity has a significant impact on LV performance in patients with acromegaly. In subjects with active disease, diastolic dysfunction and beginning impairment of overall LV performance are present. In patients with cured/well-controlled disease, systolic and diastolic function appear normal.

High output heart failure in patients with newly diagnosed acromegaly

PURPOSE

We sought to determine the prevalence and characteristics of heart failure in patients with newly diagnosed acromegaly.

SUBJECTS AND METHODS

We assessed 102 consecutive patients who had acromegaly (44 men; age range, 22 to 71 years) for signs and symptoms of heart failure. We included a control group of 33 nonobese healthy subjects (13 men; age range, 26 to 70 years). Cardiac morphologic parameters, left ventricular mass index, ejection fraction, end-systolic wall stress, and cardiac index were measured by echocardiography. Endocrinological assessment was performed in all participants.

RESULTS

Of the 102 patients, 10 (10%) had overt heart failure at the time of diagnosis of acromegaly, 9 of whom were men (P <0.01). Patients with acromegaly and heart failure had an increased mean (+/- SD) left ventricular end-diastolic diameter (76 +/- 11 mm) compared with those without heart failure (53 +/- 6 mm, P <0.001) and control subjects (49 +/- 5 mm, P <0.001). Patients with heart failure had higher left ventricular mass index (230 +/- 56 g/m2 vs. 118 +/- 40 g/m(2), P <0.001) and end-systolic wall stress (237 +/- 79 x 10(3) dyn/cm2 vs. 111 +/- 42 x 10(3) dyn/cm2, P <0.001), but lower ejection fraction (42% +/- 17% vs. 66% +/- 9%, P <0.001), in comparison with patients without heart failure. The mean cardiac index was significantly higher in patients with heart failure (4.3 +/- 1.8 L/min-m2) than in those without heart failure (3.5 +/- 0.8 L/min-m2, P = 0.04) or in control subjects (3.1 +/- 0.6 L/min-m2, P = 0.002). Two factors were independently associated with heart failure in acromegalic patients: cardiac index (odds ratio [OR] per SD of 1.0 L/min-m2 = 16; 95% confidence interval [CI]: 1.8 to 135) and ejection fraction (OR per SD of 12% = 0.7; 95% CI: 0.6 to 0.9).

CONCLUSION

High output heart failure with a modest decline in ejection fraction is frequently detected at the time of diagnosis of acromegaly. Left ventricular hypertrophy in these patients is characterized by a dilated ventricle and an increased left ventricular mass that is primarily due to the enlarged chamber diameter.

Acromegaly: evidence for a direct relation between disease activity and cardiac dysfunction in patients without ventricular hypertrophy

BACKGROUND AND AIMS

Cardiac abnormalities, such as cardiomegaly and congestive heart failure, occur frequently in advanced acromegaly. Abnormalities of systolic and diastolic function, mostly associated with left ventricular (LV) hypertrophy, have been reported. The impact of disease activity on LV performance in patients with normal or slightly elevated LV muscle mass has not been demonstrated.

PATIENTS AND METHODS

Conventional two-dimensional/Doppler echocardiography and tissue Doppler imaging (TDI) of the mitral annulus were performed in 13 patients with active acromegaly (AA) and normal or slightly elevated LV muscle mass (< 140 g/m2) and in 19 cured/well-controlled patients (CA). A group of 21 volunteers without symptoms or signs of cardiac disease served as controls (CON). The combined myocardial performance index (Tei-Index) was determined in all patients and controls.

RESULTS

Muscle mass index of the left ventricle, ejection fraction, fractional shorting, E/ET-ratio, systolic (ST) and late diastolic (AT) annular velocities did not differ significantly between the three groups. In the AA group, the early diastolic annular velocity ET[7.13 +/- 2.11 (AA); 9.83 +/- 3.29 (CA); 10.10 +/- 1.70 m/s (CON); P < 0.05 AA vs. CA, P < 0.005 AA vs. CON] and the ET/AT-ratio [0.71 +/- 0.26 (AA); 0.95 +/- 0.33 (CA); 1.00 +/- 0.15 m/s (CON); P < 0.05 AA vs. CA, P < 0.005 AA vs. CON] were significantly reduced. Patients with AA had a longer deceleration time [209 +/- 19 (AA); 179 +/- 22 (CA); 185 +/- 26 ms (CON); P < 0.05]. The Tei-Index was significantly higher in AA in comparison with CON [0.50 +/- 0.15 (AA); 0.48 +/- 0.12 (CA); 0.41 +/- 0.10 (CON); P < 0.05 AA vs. CON]. Subjects with CA did not differ significantly from controls with respect to 2-D/Doppler echo- and TDI-derived parameters.

CONCLUSION

The data demonstrate that diastolic dysfunction can be verified by tissue Doppler imaging in patients with active acromegaly with normal or slightly elevated muscle mass of the left ventricle and seems to be related to disease activity. The Tei-Index as a sensitive combined myocardial performance index can be used to complete the assessment of systolic and diastolic LV performance in acromegalic patients.

Left ventricular hypertrophy in hypertension as a predictor of coronary events: relation to geometry

The present review examines epidemiological evidence for a relation of left ventricular hypertrophy with coronary heart disease, and mechanisms that may represent pathophysiological links between left ventricular hypertrophy and coronary events. Left ventricular hypertrophy has been demonstrated to be a powerful predictor of coronary heart disease, and when geometry is concentric the relation is even stronger. In addition to its association with risk factors for atherosclerosis and mechanisms that precipitate acute heart attacks, left ventricular hypertrophy also directly predisposes to and aggravates clinical presentation of coronary heart disease through a number of biological mechanisms. These include the following: increase in oxygen requirement related to left ventricular geometry; coronary hypertension, with endothelial dysfunction and reduced coronary reserve; diastolic dysfunction; and structural remodelling of myocardium and vascular bed. Some of these alterations are also worsened by underlying coronary heart disease, and can potentially be maintained by loop mechanisms. A recognizable stage of abnormal coronary haemodynamics in the context of left ventricular hypertrophy is probably that at which coronary reserve is impaired in the absence of any other sign of heart disease; in many circumstances, this may occur early in the disease process.

Inverse association between free insulin-like growth factor-1 and isovolumic relaxation in arterial systemic hypertension

Several trials have suggested that insulin-like growth factor-1 (IGF-1) may have a pathophysiological role in the development of arterial essential hypertension. To verify the possible association of IGF-1 with left ventricular morphological and functional echocardiographic parameters in hypertension, we studied 40 male patients with newly diagnosed hypertension and 15 normotensive control subjects. Doppler echocardiography was performed and circulating free IGF-1 levels were determined in all subjects. Circulating free IGF-1 levels were higher in hypertensives than in control subjects (P<0.01). A significant inverse correlation was observed between free IGF-1 and isovolumic relaxation time in the overall population (r=-0.37, P<0.01) and in hypertensives (r=-0.57, P<0.0001), whereas this relation disappears in normotensives. These results were confirmed by multivariate analysis. The present study confirms that arterial essential hypertension represents a clinical condition associated with an increased synthesis of IGF-1. The observation of an inverse, independent association between free IGF-1 and isovolumic relaxation time suggests 2 alternative hypotheses: a possible beneficial effect of IGF-1 to diastolic relaxation or a resistance to IGF-1 in hypertension.

Marked improvement in cardiovascular function after successful transsphenoidal surgery in acromegalic patients

OBJECTIVE

Transsphenoidal surgery results in biochemical remission of acromegaly in 45-80% of patients; however, few studies have addressed the impact of transsphenoidal surgery on cardiovascular function in acromegalic patients. The aim of this prospective study was to investigate the effects of postoperative GH/IGF-I normalization on echocardiographic parameters and blood pressure (BP) in a series of patients with active acromegaly.

DESIGN

An open prospective study.

PATIENTS

Thirty newly diagnosed acromegalic patients undergoing transsphenoidal surgery.

MEASUREMENTS

Doppler echocardiography and 24-h ambulatory blood pressure monitoring were performed before and 6 months after transsphenoidal surgery.

RESULTS

Fifteen patients were considered to be well controlled postoperatively (group A), as defined by normal age-corrected IGF-I levels and glucose-suppressed GH levels less than 2 mU/l, the remaining 15 patients being considered as poorly controlled (group B). In group A, a postoperative decrease of left ventricular mass index was observed (104.4 +/- 6.6 vs. 127.1 +/- 7.7 g/m2; P < 0.001), associated with an improvement of some indices of diastolic function, such as an increase of the early/late transmitral peak flow velocity (P < 0.05) and a decrease of isovolumic relaxation time (P < 0.01). No significant change was observed in group B. A significant decrease of 24-h systolic BP was also observed in group A (P < 0.05) and five of six patients normalized their BP circadian rythm. In contrast, a nonsignificant increase in BP values, with a persistent blunted BP profile where present, was observed in group B.

CONCLUSIONS

We conclude that successful transsphenoidal surgery is able to induce a significant improvement in some cardiac parameters and a slight reduction in systolic blood pressure in acromegalic patients.

Cardiovascular complications in acromegaly: methods of assessment

Cardiac involvement is common in acromegaly. Evidence for cardiac hypertrophy, dilation and diastolic filling abnormalities has been widely reported in literature. Generally, ventricular hypertrophy is revealed by echocardiography but early data referred increased cardiac size by standard X-ray. Besides, echocardiography investigates cardiac function and value disease. There are new technologic advances in ultrasonic imaging. Pulsed Tissue Doppler is a new non-invasive ultrasound tool which extends Doppler applications beyond the analysis of intra-cardiac flow velocities until the quantitative assessment of the regional myocardial left ventricular wall motion, measuring directly velocities and time intervals of myocardium. The radionuclide techniques permit to study better the cardiac performance. In fact, diastolic as well as systolic function can be assessed at rest and at peak exercise by equilibrium radionuclide angiography. This method has a main advantage of providing direct evaluation of ventricular function, being operator independent. Coronary artery disease has been poorly studied mainly because of the necessity to perform invasive procedures. Only a few cases have been reported with heart failure study by coronarography and having alterations of perfusion which ameliorated after somatostatin analog treatment. More recently, a few data have been presented using perfusional scintigraphy in acromegaly, even if coronary artery disease does not seem very frequent in acromegaly. Doppler analysis of carotid arteries can be also performed to investigate atherosclerosis: however, patients with active acromegaly have endothelial dysfunction more than clear-cut atherosclerotic plaques. In conclusion, careful assessments of cardiac function, morphology and activity need in patients with acromegaly.

Link of nonhemodynamic factors to hemodynamic determinants of left ventricular hypertrophy

Despite current evidence suggesting that hemodynamic load is the fundamental stimulus to begin the sequence of biological events leading to the development of left ventricular hypertrophy, genotype, gender, body size, and less easily recognizable environmental factors may contribute to generate the cascade of molecular changes that eventually yield the increase in protein synthesis needed to increase left ventricular mass. However, even nonhemodynamic factors such as gender and body size eventually regulate the growth of left ventricular mass by at least in part influencing loading conditions. Consideration of measurable factors, such as gender, body size, and hemodynamic load, allows evaluation of individual echocardiographic left ventricular mass as the deviation from the level that would be required to face a gender-specific hemodynamic load at a given body size. Values of left ventricular mass that are inappropriately high for individual gender, body size, and hemodynamic load are associated with a high cardiovascular risk phenotype, even independent of the presence of arterial hypertension. Thus, the condition of inappropriately high left ventricular mass may be recognized as a more advanced stage of pathological structural changes initially induced by overload, going beyond the compensatory needs. The biological process that yields inappropriate left ventricular mass is probably linked to the protracted activity over time of biological mediators of left ventricular hypertrophy, such as proto-oncogenes and other growth factors, neurohormones, and cytokines, inducing structural modifications that initially compensate imposed overload but eventually change the structure of myocardial tissue and the composition of motor units.

Relationship between blood pressure and glucose tolerance in acromegaly

BACKGROUND

Hypertension represents a well-known risk factor for cardiovascular diseases. The pathogenesis of hypertension in acromegaly is commonly viewed as multifactorial, but the possible influence of metabolic disorders on blood pressure (BP) in affected patients is largely unknown.

OBJECTIVE

The aim of the present study was to evaluate the impact of glucose metabolism abnormalities on BP values in a series of patients with active acromegaly.

DESIGN

An open multicentre prospective study.

PATIENTS

Sixty-eight patients with active disease, aged 47.5 +/- 11.7 years, have been studied. Thirty-nine had normal glucose tolerance (NGT), 16 impaired glucose tolerance (IGT) and 13 suffered from diabetes mellitus (DM).

MEASUREMENTS

Mean clinical BP values were calculated as the mean of BP values obtained by sphygmomanometric measurement in three separate occasions and mean 24-h, diurnal and nocturnal systolic (SBP) and diastolic (DBP) values were obtained by 24-h ambulatory blood pressure monitoring (ABPM).

RESULTS

Patient's age and the degree of glucose tolerance abnormalities were found to significantly and independently influence BP values. All clinical and ABPM SBP and DBP values significantly increased with age by linear regression (P < 0.02 for all BP values, 0.30 < or = R < or = 0.43), and the independent influence of this parameter on BP values was confirmed by mutivariate analysis. Similarly, the independent influence of glucose tolerance abnormalities on BP values was confirmed when introducing age as a covariable in a multivariate analysis, and patients with DM presented significantly higher clinical SBP and 24-h, diurnal and nocturnal SBP and DBP than patients with NGT (P < 0.02 for clinical SBP, P < 0.015 for all ABPM values, respectively). In addition, patients with DM showed significantly higher 24-h, diurnal and nocturnal DBP than those with IGT (P < 0.05 in all cases). In contrast, no significant difference was found between NGT and IGT patients. No significant influence of disease duration, BMI, GH, IGF-I, or fasting and 2-h post glucose load insulinaemia on BP values was observed.

CONCLUSIONS

Abnormalities of glucose metabolism significantly contribute to increase systolic blood pressure and especially diastolic blood pressure in acromegalic patients. Careful control of blood pressure and of risk factors for developing systemic hypertension, with special reference to glucose tolerance, is mandatory to decrease cardiovascular morbidity and mortality in such patients.

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