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

Filling the gap between the heart and the body in acromegaly: a case-control study

OBJECTIVE

Cardiovascul diseases are the most common comorbidities in acromegaly. Potential parameters in pathology of cardiovascular comorbidities are changes in levels of growth hormone (GH) and insulin-like growth factor 1 (IGF-1) as well as body composition parameters.

PURPOSE

The aim of this study was to examine morphological and functional parameters of the cardiovascular system by echocardiography and to assess its relationship with disease activity and body composition parameters.

METHODS

We prospectively enroled 129 acromegalic patients (82 females, 47 males) and 80 healthy controls (53 females, 27 males) matched for age, gender, and BMI. All patients underwent two-dimensional echocardiography. Body composition parameters were assessed by dual-energy X-ray absorptiometry.

RESULTS

Acromegaly patients presented with higher left ventricle mass (LVM) compared to controls (LVMI: 123 ± 45 g/m² vs 83 ± 16 g/m², P < 0.001). Prevalence of left ventricle hypertrophy in acromegaly patients was 67% (78% concentric, 22% eccentric). IGF -1 levels, BMI, and lean mass positively correlated with LVM in all acromegaly patients (P < 0.001). Fat mass positively correlated with LVM in females (R = 0.306, P = 0.005), but this correlation was not found in males. We did not find any difference in size of the left and right ventricle between acromegaly patients and controls. Acromegaly patients presented with left atrium enlargement, diastolic dysfunction and low incidence of systolic dysfunction. Valvopathy was found in 43% of patients with predominant (31%) prevalence of mitral regurgitation.

CONCLUSION

Our study demonstrates higher prevalence of cardiovascular comorbidities in acromegaly patients and the impact of IGF-1 levels and body composition parameters in pathology in some of these comorbidities.

Coronary Flow Velocity Reserve by Echocardiography: Beyond Atherosclerotic Disease

Coronary flow velocity reserve (CFVR) is defined as the ratio between coronary flow velocity during maximal hyperemia and coronary flow at rest. Gold-standard techniques to measure CFVR are either invasive or require radiation and are therefore inappropriate for large-scale adoption. More than 30 years ago, echocardiography was demonstrated to be a reliable tool to assess CFVR, and its field of application rapidly expanded. Although initially validated to assess the hemodynamic relevance of a coronary stenosis, CFVR by echocardiography was later used to investigate coronary microcirculation. Microvascular dysfunction was detected in many different conditions, ranging from organ transplantation to inflammatory disorders and from metabolic diseases to cardiomyopathies. Moreover, it has been proven that CFVR by echocardiography not only detects coronary microvascular involvement but is also an effective prognostic factor that allows a precise risk stratification of the patients. In this review, we will summarize the many applications of CFVR by echocardiography, focusing on the coronary involvement of systemic diseases.

Serum Elabela level is significantly increased in patients with acromegaly

BACKGROUND

Although the bioactive peptides associated with the apelinergic system are known to be associated with heart failure and ischemic heart disease, there are no data on their association with acromegaly.

AIM

We aimed to investigate the change in serum Elabela levels, a novel peptide of the apelinergic system, in patients with acromegaly.

METHODS

Our study included 30 treatment naive patients who were recently diagnosed with acromegaly, and 50 age-and-sex-matched healthy controls. In addition to routine history, physical examination and laboratory examinations, serum Elabela level was measured. Participants were divided into two groups as individuals with and without acromegaly and compared to each other.

RESULTS

Diastolic blood pressure (DBP) and systolic blood pressure (SBP) were found to be higher in patients with acromegaly. Serum glucose, Hs-CRP, NT-proBNP, insulin-like growth factor-1, growth hormone and serum Elabela levels were higher in patients with acromegaly (p < 0.05 for each). Left ventricular ejection fraction (LV-EF) was found to be lower in patients with acromegaly than the patients in healthy control group (p < 0.05). In multivariate analysis; age, systolic blood pressure, NT-proBNP, Insulin-like growth factor 1 and growth hormone levels were found to be very closely and positively related to serum Elabela level (p < 0.05 for each).

CONCLUSIONS

Serum Elabela level can be used as an early and objective indicator of early cardiovascular involvement in patients with acromegaly. Further research is needed to clarify the role of serum Elabela levels on cardiovascular system in acromegaly patients.

Increased insulin-like growth factor 1 concentrations in a retrospective population of non-diabetic cats diagnosed with hypertrophic cardiomyopathy

OBJECTIVES

The aim of the study was to document whether a proportion of non-diabetic cats with left ventricular hypertrophy (LVH) previously diagnosed with hypertrophic cardiomyopathy (HCM) have elevated circulating insulin-like growth factor 1 (IGF-1) concentrations.

METHODS

A retrospective analysis of residual blood samples obtained at the time of echocardiographic diagnosis of HCM from a population of 60 non-diabetic cats were analysed for circulating IGF-1 concentrations using a validated radioimmunoassay and compared with a control group of 16 apparently healthy cats without LVH. Clinical and echocardiographic data for cats with an IGF-1 level >1000 ng/ml were compared with those with an IGF-1 level <800 ng/ml.

RESULTS

In total, 6.7% (95% confidence interval 1.8-16.2%) of cats with HCM had an IGF-1 level >1000 ng/ml. The prevalence of an IGF-1 level >1000 ng/ml in the control group was zero.

CONCLUSIONS AND RELEVANCE

A small proportion of non-diabetic cats previously diagnosed with HCM had an IGF-1 concentration at a level that has been associated with feline hypersomatotropism (fHS) in the diabetic cat population. Further prospective research is required to confirm or refute the presence of fHS in non-diabetic cats with LVH and increased IGF-1.

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 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.

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.

Acromegalic cardiomyopathy: Epidemiology, diagnosis, and management

Acromegalic cardiomyopathy is the leading cause of morbidity and all-cause mortality in patients with acromegaly. Though acromegaly is a rare condition, the associated derangements are vast and severe. Stemming from an increase in circulating growth hormone (GH) and insulin-like growth factor-1 levels (IGF-1), acromegalic cardiomyopathy results in pathological changes in myocyte growth and structure, cardiac contractility, and vascular function. These molecular changes manifest commonly as biventricular hypertrophy, diastolic and systolic dysfunction, and valvular regurgitation. Early recognition of the condition is paramount, though the insidious progression of the disease commonly results in a late diagnosis. Biochemical testing, based on IGF-1 measurements, is the gold standard of diagnosis. Management should be centered on normalizing serum levels of both IGF-1 and GH. Transsphenoidal resection remains the most cost-effective and permanent treatment for acromegaly, though medical therapy possesses benefit for those who are not surgical candidates. Ultimately, achieving control of hormone levels results in a severe reduction in mortality rate, underscoring the importance of early recognition and treatment.

Two-dimensional speckle tracking echocardiography demonstrates no effect of active acromegaly on left ventricular strain

BACKGROUND

Speckle tracking echocardiography (STE) allows for the study of myocardial strain (ε), a marker of early and subclinical ventricular systolic dysfunction. Cardiac disease may be present in patients with acromegaly; however, STE has never been used to evaluate these patients.

OBJECTIVE

To evaluate left ventricular (LV) global longitudinal strain in patients with active acromegaly with normal LV systolic function.

DESIGN

Cross-sectional clinical study.

METHODS

Patients with active acromegaly with no detectable heart disease and a control group were matched for age, gender, arterial hypertension and diabetes mellitus underwent STE. Global LV longitudinal ε (GLS), left ventricular mass index (LVMi), left ventricular ejection fraction (LVEF) and relative wall thickness (RWT) were obtained via two-dimensional (2D) echocardiography using STE.

RESULTS

Thirty-seven patients with active acromegaly (mean age 45.6 ± 13.8; 48.6% were males) and 48 controls were included. The mean GLS was not significantly different between the acromegaly group and the control group (in %, -20.1 ± 3.1 vs. -19.4 ± 2.2, p = 0.256). Mean LVMi was increased in the acromegaly group (in g/m², 101.6 ± 27.1 vs. 73.2 ± 18.6, p < 0.01). There was a negative correlation between LVMi and GLS (r = -0.39, p = 0.01).

CONCLUSIONS

Acromegaly patients, despite presenting with a higher LVMi when analyzed by 2D echocardiography, did not present with impairment in the strain when compared to a control group; this finding indicates a low chance of evolution to systolic dysfunction and agrees with recent studies that show a lower frequency of cardiac disease in these patients.

ASSESSMENT OF DIASTOLIC DYSFUNCTION, ARTERIAL STIFFNESS, AND CAROTID INTIMA-MEDIA THICKNESS IN PATIENTS WITH ACROMEGALY

OBJECTIVE

Early diagnosis and treatment of cardiovascular diseases, the most frequent cause of morbidity and mortality in acromegaly, may be an efficient approach to extending the lifespan of affected patients. Therefore, it is crucial to determine any cardiovascular diseases in the subclinical period. The study objectives were to determine markers of subclinical atherosclerosis and asses heart structure and function.

METHODS

This was a cross-sectional, single-center study of 53 patients with acromegaly and 22 age- and sex-matched healthy individuals. Carotid intima-media thickness (CIMT), pulse-wave velocity (PWV), and echocardiographic data were compared between these groups.

RESULTS

CIMT and PWV were higher in the acromegaly group than in the healthy group (P = .008 and P = .002, respectively). Echocardiography showed that left ventricular diastolic dysfunction was present in 11.3% of patients. Left ventricular mass index and left atrial volume index were higher in the patients (P = .016 and P<.001, respectively). No differences in the CIMT, PWV, or echocardiographic measurements were identified between the patients with biochemically controlled and uncontrolled acromegaly and the control group.

CONCLUSION

Our results showed that subclinical atherosclerosis (i.e., CIMT and PWV markers) and heart structure and function were worse in patients with acromegaly than in healthy individuals. Because there were no differences in these parameters between patients with controlled and uncontrolled acromegaly, our results suggest that the structural and functional changes do not reverse with biochemical control.

ABBREVIATIONS

AA = active acromegaly BSA = body surface area CA = biochemically controlled acromegaly CH = concentric hypertrophy CIMT = carotid intima-media thickness DBP = diastolic blood pressure DM = diabetes mellitus ECHO = echocardiography EDV = enddiastolic volume EF = ejection fraction ESV = endsystolic volume GH = growth hormone HC = healthy control HL = hyperlipidemia HT = hypertension IGF-1 = insulin-like growth factor 1 LA = left atrial LAV = left atrial volume LAVI = left atrial volume index LV = left ventricular LVDD = left ventricular diastolic dysfunction LVEF = left ventricular ejection fraction LVH = left ventricular hypertrophy LVMI = left ventricular mass index PWV = pulse-wave velocity RWT = relative wall thickness.