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

Acromegaly: The Relationship between Hemodynamic Profiles Assessed via Impedance Cardiography and Left Ventricular Systolic Function Assessed via Echocardiography

Background/Objectives: Acromegaly-induced prolonged exposure to growth hormone and insulin-like growth factor 1 may have significant cardiovascular effects. The purpose of this study was to assess the relationship between hemodynamic parameters measured via impedance cardiography (ICG) and parameters of systolic left ventricular function measured via echocardiography in patients with acromegaly. Methods: The observational cohort study included 33 patients with newly diagnosed acromegaly, with a mean age of 47 years and without significant comorbidities. Correlation analysis (Spearman's rank correlation coefficient R) was performed on parameters obtained by ICG and left ventricular systolic function parameters obtained by echocardiography. ICG assessment included indices of (1) cardiac function as a pump: stroke volume index (SI), cardiac index (CI), Heather index (HI), velocity index (VI), and acceleration index (ACI); (2) afterload: systemic vascular resistance index (SVRI) and total arterial compliance index (TACI); and (3) thoracic fluid content (TFC). Echocardiographic examinations evaluated left ventricular ejection fraction (LVEF) and global longitudinal strain (GLS). Results: A lower LVEF was associated with a lower SI (R = 0.38; p = 0.03) and a higher SVRI (R = -0.35; p = 0.046), whereas lower GLS was associated with lower SI (R = 0.43; p = 0.02), CI (R = 0.62; p < 0.001), VI (R = 0.59; p < 0.001), ACI (R = 0.38; p = 0.048), HI (R = 0.59; p < 0.001), and TACI (R = 0.50; p = 0.006) and a higher SVRI (R = -0.59; p < 0.001). No significant correlation was observed between either LVEF or GLS and TFC. Conclusions: In patients with acromegaly, poorer echocardiographic parameters of left ventricular systolic function are associated with impaired function of the heart as a pump and higher afterload as assessed via ICG.

Myocardial, Valvular, and Vascular Structural and Functional Properties in Acromegaly

Acromegaly is an uncommon systematic endocrine disease caused by the hypersecretion of human growth hormone and, consequently, of insulin-like growth factor-1 during adulthood. Acromegaly could cause a typical cardiomyopathy characterized by left ventricular hypertrophy associated with diastolic dysfunction, which later could progress to systolic dysfunction. Moreover, some valvular and vascular abnormalities are also associated with acromegaly. This present review aims to summarize available information regarding acromegaly-associated abnormalities in myocardial, valvular, and vascular structural and functional properties and their relationship to disease activity and treatment options.

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.

Advances in Research on the Cardiovascular Complications of Acromegaly

Cardiovascular-related complications are one of the most common complications in patients with acromegaly, and can lead to an increased risk of death. Hypertension and cardiomyopathy are the main cardiovascular complications. The characteristics of acromegalic cardiomyopathy are concentric biventricular hypertrophy and diastolic dysfunction. In addition, arrhythmia and heart valve disease are common cardiac complications in acromegaly. Although the underlying pathophysiology has not been fully elucidated, the spontaneous overproduction of GH and IGF-1, increasing age, prolonged duration of disease and the coexistence of other cardiovascular risk factors are crucial to cardiac complications in patients with acromegaly. Early diagnosis and appropriate treatment of acromegaly might be beneficial for the prevention of cardiomyopathy and premature death.

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.

Acromegaly and ultrasound: how, when and why?

BACKGROUND

Acromegaly is a rare disease caused by an excess of growth hormone and insulin-like growth factor 1. It is usually diagnosed because of typical signs such as macroglossia, acral enlargement, jaw prognathism and malocclusion. Systemic complications are a major cause of morbidity and mortality in acromegaly, and many patients remain undiagnosed for several years. Increased ultrasound (US) application in the general population, and including among acromegaly patients, has revealed many suggestive features which, taken together with clinical suspicion, could induce suspicion of this disease.

PURPOSE

This review describes main US features in acromegaly. Echocardiography shows a typical cardiomyopathy, characterized by left ventricular hypertrophy, diastolic and systolic dysfunction, aortic and mitral regurgitation, and increased aortic root diameters. US preclinical markers of atherosclerosis, such as intima media thickness (IMT), seem also to be impaired. Visceromegaly and increased organ stiffness are other features of acromegaly, including enlarged prostate, kidneys, liver, and thyroid. In addition, other US findings are: renal cysts, micronephrolithiasis, impairment of renal haemodynamic parameters, gallstones and gallbladder polyps, hepatic steatosis, thyroid nodules, multinodular goiter, and polycystic ovaries. Musculoskeletal US findings are increased cartilage thickness, impaired density and elasticity of bones, nerve enlargement, carpal and cubital tunnel syndrome, and trigger finger.

CONCLUSIONS

Acromegaly patients frequently present systemic complications and a diagnostic delay. US features of acromegaly are not specific, but could potentially have a key role in early detection of the disease in the presence of typical clinical features.

Left Heart Dysfunction in Acromegaly Revealed by Novel Echocardiographic Methods

Background: Acromegaly is a rare disease that requires modern treatment to decrease the risk of mortality, mainly from vascular diseases. Identifying acromegalic patients with increased cardiovascular risk is challenging. Speckle-tracking echocardiography (STE) is a modern, well-validated, and reproducible method of assessing left ventricular longitudinal deformation and providing a sensitive assessment of myocardial contractility. We hypothesized that STE may be useful in evaluating subclinical dysfunction of the left heart in acromegalic patients, especially when a left ventricle (LV) assessment is completed with STE of the left atrium (LA). Purpose: To assess the diagnostic value of speckle-tracking echocardiography in identifying the occurrence of LV and LA functional impairment in patients with acromegaly, in comparison to patients without this rare pituitary disease. Methods: Echocardiographic assessments of LV and LA function using the new STE method were performed in 60 subjects: 30 acromegalic (ACRO group) patients and a CONTROL group with 30 patients matched in terms of age, gender, systolic/diastolic pressure, and history of hypertension for at least 12 months. Results: The ACRO group, compared to the CONTROL group, presented: (1) higher left ventricular mass (left ventricular mass index: 132 vs. 108 g/m², p < 0.001) and, in consequence, more frequent LV hypertrophy (80.0 vs. 53.3%; p = 0.028); (2) impaired LV systolic function measured by both left ventricular ejection fraction (LVEF) (63.4 vs. 66.9%, p < 0.001) and global longitudinal strain (GLS) (-18.1 vs. -19.4%, p = 0.023); (3) greater LA anteroposterior diameter (40.3 vs. 36.9 mm, p = 0.003) and indexed left atrial volume (37.9 vs. 27.6 ml/m², p < 0.001); and (4) impaired echocardiographic strain parameters corresponding with LA function. Conclusions: Acromegaly, even in young patients with good blood pressure control, may be associated with left ventricular hypertrophy and subclinical impairment of the left ventricular and left atrial mechanical function, which may be identified by speckle-tracking echocardiography. Further research in this area is necessary to clarify the prognostic value of these phenomena.

Acromegaly and Heart Failure

In patients with acromegaly, chronic GH and IGF-I excess commonly causes a specific cardiomyopathy characterized by a concentric cardiac hypertrophy associated with diastolic dysfunction and, in later stages, with systolic dysfunction ending in heart failure in untreated and uncontrolled patients. Additional relevant cardiovascular complications are represented by arterial hypertension, valvulopathies, arrhythmias, and vascular endothelial dysfunction, which, together with the respiratory and metabolic complications, contribute to the development of cardiac disease and the increase cardiovascular risk in acromegaly. Disease duration plays a pivotal role in the determination of acromegalic cardiomyopathy. The main functional disturbance in acromegalic cardiomyopathy is the diastolic dysfunction, observed in 11% to 58% of patients, it is usually mild, without clinical consequence, and the progression to systolic dysfunction is generally uncommon, not seen or observed in less than 3% of the patients. Consequently, the presence of overt CHF is rare in acromegaly, ranging between 1 and 4%, in patients with untreated and uncontrolled disease. Control of acromegaly, induced by either pituitary surgery or medical therapy improves cardiac structure and performance, limiting the progression of acromegaly cardiomyopathy to CHF. However, when CHF is associated with dilative cardiomyopathy, it is generally not reversible, despite the treatment of the acromegaly.

Systemic Complications of Acromegaly and the Impact of the Current Treatment Landscape: An Update

Acromegaly is a chronic systemic disease with many complications and is associated with increased mortality when not adequately treated. Substantial advances in acromegaly treatment, as well as in the treatment of many of its complications, mainly diabetes mellitus, heart failure, and arterial hypertension, were achieved in the last decades. These developments allowed change in both prevalence and severity of some acromegaly complications and furthermore resulted in a reduction of mortality. Currently, mortality seems to be similar to the general population in adequately treated patients with acromegaly. In this review, we update the knowledge in complications of acromegaly and detail the effects of different acromegaly treatment options on these complications. Incidence of mortality, its correlation with GH (cumulative exposure vs last value), and IGF-I levels and the shift in the main cause of mortality in patients with acromegaly are also addressed.

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.

Acromegalic cardiomyopathy in an extensively admixed population: is there a role for GH/IGF-I axis?

BACKGROUND

A specific acromegaly-related cardiomyopathy has been described in the literature, largely in Caucasians, which is independent of other risk factors, mainly hypertension.

OBJECTIVE

This study assessed the cardiac changes in acromegalics of significant ethnic diversity and also the relevance of the aetiopathogenic factors involved, such as disease activity and hypertension.

DESIGN

It is a cross-sectional study with a comparative control group.

PATIENTS AND METHODS

In this study, 37 acromegalic patients (20 Intermediate-skinned (IS), 14 Dark-skinned (DS) and three Light-skinned (LS) individuals) and 74 controls matched by age, gender and hypertension were evaluated. Cardiac morphology and function were addressed using echocardiography parameters.

RESULTS

The mean age of patients was 46.9 ± 12.8 years, with 67.6% being women and 43.2% hypertensive. The prevalence of left ventricular hypertrophy (LVH) between acromegalics was 56.8% vs 10.8% in the controls (P < 0.001). About 86% of patients with LVH had active disease (P = 0.023). Logistic regression revealed that disease activity presented a stronger association (OR = 5.925; CI = 1.085-32.351; P = 0.040) with LVH than hypertension (OR = 3.237; CI = 0.702-14.924; P = 0.132). When DS acromegalics were compared with IS ones, no statistically significant differences were observed.

CONCLUSION

Chronically hyperactive somatotropic axis remains as an independent and determining factor in the development of left ventricular hypertrophy, as it is more associated with this condition than hypertension in a largely admixed population with a high degree of African ancestry.

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.

Effects of somatostatin analogues on acromegalic cardiomyopathy: results from a prospective study using cardiac magnetic resonance

OBJECTIVE

Left ventricular (LV) hypertrophy is the main finding of patients with active acromegaly at cardiac magnetic resonance (CMR). The aim of the study was to evaluate heart changes in acromegalic patients treated with somatostatin analogues (SMSA) using CMR.

DESIGN AND PATIENTS

This was a prospective study. Fourteen consecutive patients (8 women, mean age 46+/-10 yr) with untreated active acromegaly were submitted to CMR and 2D-color Doppler echocardiography before and after a 6-month SMSA course.

MEASUREMENTS

LV volume, mass (LVM) and wall thickness.

RESULTS

CMR: Mean LVM and LVM index (i) decreased from 151+/-17 g and 77+/-9 g/m2, to 144+/-24 g and 70+/-12 g/m2, respectively (p=0.047 and p<0.0001, respectively); LV hypertrophy reverted in 6 out of 10 patients (p=0.016). Systolic function, evaluated by measuring LV ejection fraction remained normal in all patients (67+/-11%). There was not a correlation between changes in LVMi and changes in serum IGF-I concentrations. However, patients with controlled disease had higher reduction of LVMi than those with uncontrolled acromegaly (DeltaLVMi, -8.2+/-4.2 vs 4.0+/-5.3 p<0.05). 2D-echo cardiography: Mean LVMi decreased from 110+/-24 g/m2 to 100+/-20 g/m2 (p=0.026); hypertrophy, revealed in 5 patients (36%) at baseline, reversed in 2 patients (p=0.500) after SMSA; abnormal diastolic function [evaluated by isovolumic relaxation time or early (E) to late of atrial (A) peak velocities ratio] found in 4 patients (29%) at the study entry, improved in a patient. Systolic function remained within the normal range in all patients during the study period.

CONCLUSIONS

CMR detects changes in LVMi in most patients with acromegaly treated with SMSA, which are more evident if the disease is controlled.

Identification, treatment and management of cardiovascular risks in patients with acromegaly

Acromegaly, a syndrome related to growth hormone/IGF-1 excess, is frequently complicated by cardiovascular abnormalities (acromegalic cardiomyopathy). Extremely frequent are left ventricular hypertrophy and alterations of diastolic filling, which may progress to systolic dysfunction and eventually heart failure. Cardiac abnormalities may normalize after successful medical or surgical treatment of acromegaly, particularly in young patients with short-lasting disease, but this is less likely to occur in elderly patients. Both hypertension and cardiac valve disease are frequently encountered in acromegaly, but neither seems to be favorably influenced by disease control. The prevalence of coronary heart disease (CHD) is controversial but is probably not increased in acromegaly. Arrhythmias are relatively common in untreated acromegalic patients, although their clinical relevance is unknown. A cardiac evaluation of acromegalic patients should include echocardiography, basal electrocardiogram and blood pressure measurement, and evaluation of common risk factors for CHD. Appropriate and prompt treatment allowing a rapid control of growth hormone/IGF-1 hypersecretion is warranted because many features of acromegalic cardiomyopathy may be reverted, particularly in younger patients. In view of the lack of association with acromegaly, common risk factors for CHD, hypertension, arrhythmias or valve disease should be managed independently, irrespective of control of disease activity.

Circulating IGF-I levels are associated with increased biventricular contractility in top-level rowers

BACKGROUND

The intensive physical activity is often associated with cardiac changes.

OBJECTIVES

(i) To evaluate the IGF-I system and myocardial structure and function by standard Doppler echocardiography and Tissue Doppler in athletes and sedentary controls; and (ii) to determine any relationship between IGF-I system and echocardiographic parameters.

METHODS

Nineteen male top-level rowers and 19 age-matched healthy sedentary male controls underwent blood determination of fasting serum IGF-I, IGFBP-3 and acid-labile subunit levels and standard Doppler echocardiography combined with pulsed Tissue Doppler of posterior septal wall, left ventricular (LV) lateral mitral annulus and right ventricular (RV) tricuspid annulus. Myocardial presystolic (PS(m)), systolic (S(m)), the ratio of early diastolic (E(m)) to atrial (A(m)) velocities as well as myocardial time intervals were calculated.

RESULTS

Rowers had higher serum IGF-I levels (P = 0.04), higher biventricular cavity dimensions and wall thicknesses compared to controls. They also had better LV and RV myocardial function than controls. In the rowers, IGF-I was associated with LV ejection fraction (r = 0.50, P = 0.03), RV PS(m) velocity (r = 0.55, P = 0.01) and with RV myocardial precontraction time (r = -0.57, P = 0.01). These associations remained significant after adjusting for age and heart rate.

CONCLUSIONS

Top-level athletes showed higher IGF-I levels and a better myocardial performance than controls, particularly for the RV systolic activity. The independent correlations between IGF-I and systolic parameters of the left (ejection fraction) and right (PS(m) velocity and precontraction time) ventricles may possibly indicate a role of IGF-I system in the modulation of myocardial inotropism in athletes. Further studies are needed to confirm this hypothesis.