Dramatic improvement of severe dilated cardiomyopathy in an acromegalic patient after treatment with octreotide and trans-sphenoidal surgery

Endocrine causes of heart failure: A clinical primer for cardiologists

Heart failure (HF) may be a presenting manifestation of a few endocrine disorders and should be considered in evaluation of heart failure causes. This clinically oriented review is an attempt to highlight the protean manifestations of heart failure in endocrine diseases which could present either as acute or chronic heart failure. Acute heart failure manifests as hypertensive crisis, Takotsubo syndrome, or as tachy/brady cardiomyopathies. Chronic heart failure could masquerade with features of hyperdynamic heart failure, or hypertrophic, restrictive or dilated cardiomyopathy. Rarely constrictive features or resistant heart failure could be the presenting feature. Isolated presentation as pulmonary hypertension and right heart failure are also documented. Good history-taking and physical examination with targeted investigations will help in the timely management for reversing the pathophysiology to a significant extent by appropriated management.

Role of imaging in the detection of reversible cardiomyopathy

Heart failure is a major clinical problem in developed countries with about half of heart failure patients exhibiting decreased left ventricular systolic function. The correct identification and prompt treatment of some specific etiologies can reverse heart failure, and recognition of myocardial recovery may avoid long-term therapy. However, the echocardiographic patterns of patients with a variety of etiologies of heart failure are similar, so the selective use of other imaging techniques is necessary for identification of specific etiologies. The role of repeat imaging in monitoring the therapeutic response is controversial, as is the cessation of medical therapy in patients demonstrating recovery.

Normalisation of plasma growth hormone levels improved cardiac dysfunction due to acromegalic cardiomyopathy with severe fibrosis

A 51-year-old man was referred to the Department of Cardiology in our hospital due to severe congestive heart failure and ventricular arrhythmias in March 2008. He had repeated ventricular tachycardia for years and the left ventricular ejection fraction (EF) was 11% on admission. A myocardial biopsy revealed that over 50% cardiomyocytes were replaced by fibrosis. Due to the typical acromegalic features, he was referred to the endocrinology department and diagnosed as acromegaly. He was treated with octreotide for 8 months followed by trans-sphenoidal surgery. The plasma levels of growth hormone (GH) and insulin-like growth factor-1 (IGF-1) decreased by octreotide and normalised by surgery after which the cardiac function improved drastically. The current case demonstrates that cardiac dysfunction in acromegaly could be recovered by normalisation of GH and IGF-1 even in the presence of severe fibrosis in the myocardium.

A case of juvenile acromegaly that was initially diagnosed as severe congestive heart failure from acromegaly-induced dilated cardiomyopathy

Acromegaly is characterized by chronic hypersecretion of growth hormone (GH) and is associated with increased mortality rate because of the potential complications such as cardiovascular disease, respiratory disease, or malignancy, which are probably caused by the long-term exposure of tissues to excess GH, for at least 10 years, before diagnosis and treatment. A 22-year-old man with a 2-month history of fatigue was admitted to our hospital because of chest discomfort, dyspnea, and pitting edema of the lower limbs experienced over a 1-month period. On admission, his height and body weight were 186 cm and 138.5 kg, respectively, with a BMI of 39.8 kg/m(2). He showed acromegalic features and elevated serum GH and IGF-1 levels, which were 11.5 ng/mL and 960 ng/mL, respectively. There was no GH suppression in the 75-g oral glucose tolerance test. Pituitary magnetic resonance imaging (MRI) revealed microadenoma. Chest X-ray revealed cardiomegaly, and echocardiogram showed dilated left ventricular (LV) cavity and diffuse hypokinesis with extremely decreased ejection fraction (EF). He was diagnosed as having acromegaly with congestive heart failure from diastolic cardiomyopathy. After the successful transsphenoidal resection of the pituitary adenoma, the level of GH was normalized. However, the cardiac dysfunction did not show any improvement even after the administration of β-blockers, angiotensin-converting enzyme inhibitor (ACE-I), or diuretics. The patient was re-hospitalized, and he died of cardiac failure at the age of 25 years. Patients with acromegaly have been reported to have about 30% higher mortality rate, and cardiovascular disease accounts for 60% of the deaths. We report a case of a patient with juvenile acromegaly who was diagnosed with severe cardiac failure at the time of diagnosis and failed to recover cardiac function even after the successful resection of the pituitary adenoma. Immediate diagnosis and treatment are required for better control of acromegalic cardiomyopathy.

Rapidly reversible myocardial edema in patients with acromegaly: assessment with ultrafast T2 mapping in a single-breath-hold MRI sequence

OBJECTIVE

The purpose of this study was to use a single-breath-hold T2-mapping MRI sequence to evaluate the reversibility of myocardial edema in patients treated for acromegaly.

SUBJECTS AND METHODS

Before and after treatment, 15 patients with acromegaly underwent myocardial T2 mapping with an experimental single-breath-hold black-blood fast spin-echo sequence. Myocardial T2 mapping with both a multiple-breath-hold fast spinecho sequence and the experimental sequence also was performed on 14 volunteers. T2 relaxation times were calculated with a standard linear least-squares fit applied to myocardial signal intensity. The T2 relaxation times of patients were compared with those of volunteers and correlated with levels of serum growth hormone and insulinlike growth factor 1. Left ventricular function and mass index were determined with cine MRI.

RESULTS

T2 values before treatment were higher in patients (71 +/- 12 milliseconds) than in volunteers (55.9 +/- 3.6 milliseconds) (p = 0.0003). These T2 values in patients decreased soon after treatment (57.6 +/- 6.6 milliseconds, p = 0.0007). This reduction correlates with successful reduction of levels of serum growth hormone and insulinlike growth factor 1. In volunteers, myocardial T2 values did not vary significantly between the single-breath-hold sequence and the multiple-breath-hold fast spin-echo sequence. In patients, myocardial mass and left ventricular function did not differ significantly before and after treatment.

CONCLUSION

Patients with acromegaly have increased myocardial T2 values, which decrease soon after treatment, reflecting reversible myocardial edema. T2 value is more sensitive than left ventricular mass index in the detection of early reversal of acromegalic cardiomyopathy. These results highlight the potential role of MRI in direct assessment of the tissular effects of growth hormone and insulinlike growth factor 1 and in evaluation of the efficacy of treatment.

Reversible cardiomyopathies

Cardiomyopathy represents a diverse and heterogenous group of disorders affecting the myocardium and ultimately resulting in cardiac dysfunction. The prevalence of heart failure is high (5 million symptomatic patients in the United States) and increasing. Cardiomyopathy is the leading cause of hospitalization in patients older than 65 years of age, resulting in enormous healthcare expenditure and lost productivity. Ischemic cardiomyopathy accounts for about half of these patients, but in several large clinical trials the prevalence of potentially reversible nonischemic cardiomyopathy is also significant, ranging from 20% to 50%. There is epidemiological evidence that the prognosis of these reversible nonischemic cardiomyopathies is better than ischemic or other nonreversible cardiomyopathies. Early and precise diagnosis of the etiology of heart failure is important for determining prognosis and effective treatments.

Resolution of acromegalic cardiomyopathy in mild acromegalic physical abnormality after short-term octreotide therapy

Congestive heart failure developed in a 42-year-old man who had very mild acromegalic features. Echocardiography showed a marked dilatation of the left ventricle and decreased systolic function. Laboratory examinations revealed the elevated levels of growth hormone and insulin-like growth factor-1 and pituitary microadenoma was demonstrated by magnetic resonance imaging. Although the extensive conventional medical treatment was ineffective, short-term addition of somatostatin analog, octreotide, rapidly improved his cardiac function. After discontinuation of octreotide, further improvement was observed with minimal residual diastolic dysfunction. All medical treatment could be stopped after successful trans-sphenoidal surgery. Early diagnosis and effective treatment is important to reverse the acromegalic cardiomyopathy.

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.

The influence of growth hormone status on physical impairments, functional limitations, and health-related quality of life in adults

The availability of recombinant human GH and somatostatin analogs has resulted in widespread treatment for adults with GH deficiency (GHD) and those with GH excess (acromegaly). Despite being at opposite ends of the spectrum in terms of their GH/IGF-I axis, both of these populations experience overlapping somatic impairments. Adults with untreated GHD have low circulating levels of IGF-I that manifest as altered body composition with increased fat and reduced lean body and skeletal muscle mass. At the other end of the spectrum, adults with GH excess, who have elevated levels of IGF-I, also have altered body composition. Impairments that result from disorders of either GHD or GH excess are both associated with increased functional limitations, such as reduced ability to walk quickly for prolonged periods, and poorer health-related quality of life (HR-QoL). Adults with untreated GHD and GH excess both commonly complain of excessive fatigue that seems to be associated more with impaired aerobic than muscular performance. Several studies have documented that administration of GH or somatostatin analogs to adults with GHD or GH excess, respectively, ameliorates abnormal biochemical profile and the associated somatic impairments. However, whether these improvements translate into improved physical function in adults with GHD or GH excess remains largely unknown, and their impact on HR-QoL controversial. Review of placebo-controlled trials to date suggests that GH and somatostatin analogs have greater effects on gas exchange and aerobic performance than as anabolic agents on skeletal muscle mass and function. Future investigations should include dose-response studies to establish the optimal combination of pharmacological agents plus exercise required to improve not only biochemical markers but also physical function and HR-QoL in adults with GHD or GH excess.

Acute Onset of Severe Dilated Cardiomyopathy During Bromocriptine Therapy

OBJECTIVE:

To report a case of severe dilated cardiomyopathy (DCMP) in a patient on bromocriptine therapy for a microprolactinoma.

CASE SUMMARY:

A 31-year-old African American female, who had been receiving bromocriptine 5 mg orally daily for a microprolactinoma during the preceding month, developed severe DCMP. An echocardiogram showed a markedly dilated left ventricle with severe reduction in the left-ventricular ejection fraction in the absence of any other identifiable causes of DCMP such as a peripartum state, ethanol use, preceding systemic viral illness, chronic hypocalcemia, chronic hypophosphatemia, or chronic uncontrolled tachycardia. She improved substantially (both symptomatically and echocardiographically) after cessation of bromocriptine therapy and initiation of supportive treatment of congestive heart failure (CHF). She showed no recurrence of CHF at a follow-up visit 2 months after withdrawal of the supportive care. The patient was not rechallenged with bromocriptine due to the clinical/ethical gravity of this probable adverse effect.

DISCUSSION:

Although cardiopulmonary adverse effects have been reported with the use of cabergoline (another dopamine agonist), to the best of our knowledge, this is the first case report of severe life-threatening DCMP associated with bromocriptine therapy. Causality assessment using the Naranjo probability scale revealed that the adverse drug event was probable.

CONCLUSIONS:

Bromocriptine was probably associated with DCMP in a patient being treated for a microprolactinoma. Severe DCMP needs to be considered a potentially life-threatening but reversible adverse effect of bromocriptine therapy for microprolactinoma of the pituitary gland.

A 24-hour comparison of serum growth hormone concentrations in patients with heart failure versus healthy controls

STUDY OBJECTIVE

To compare endogenous serum growth hormone concentrations over a 24-hour period in patients with chronic heart failure (CHF) and matched controls.

DESIGN

Prospective, 24-hour, endogenous concentration comparison.

SETTING

Hospital research center.

PATIENTS

Eight evaluable patients with nonischemic dilated cardiomyopathy and 10 healthy control subjects, matched for age and sex.

INTERVENTION

Over a 24-hour period, blood was drawn from the study participants every 20 minutes for determination of growth hormone.

MEASUREMENTS AND MAIN RESULTS

For each patient, the area under the concentration-time curve from time 0-24 hours (AUC0-24), maximum concentration (Cmax), and minimum concentration (Cnadir) of growth hormone were determined. The AUC0-24 and Cmax were 74% (p < 0.05) and 62% (p < 0.05) lower in patients with CHF than in controls, respectively. The Cnadir for all participants was 0 microg/L. Variability in growth hormone concentrations over the 24 hours was considerable for all study participants.

CONCLUSIONS

Growth hormone concentrations are suppressed over a 24-hour period in patients with CHF versus healthy controls. Variability in levels throughout the day suggests that a single point evaluation cannot be used to determine deficiency or abundance of growth hormone.

Ventilation threshold as a measure of impaired physical performance in adults with growth hormone excess

OBJECTIVE

Fatigue is a prominent symptom among patients with GH excess and acromegaly. Identifying the physiological basis of such complaints and obtaining objective measures to quantify their severity remains an ongoing challenge. We investigated whether submaximal measures of aerobic performance can be used to assess GH excess-associated fatigue objectively.

DESIGN AND PATIENTS

To investigate this possibility we examined the relation between physical function and physical capacity in 12 patients with active acromegaly and persistent fatigue before and after 3 and 6 months of treatment with the long-acting somatostatin analogue octreotide (LAR(R)).

MEASUREMENTS

Heart rate (HR) and rating of perceived exertion (RPE using Borg's 10-point scale) were measured during a 160-metre self-paced walk test (SPW). Maximum oxygen uptake (VO2max) and ventilation threshold (VeT: a measure of work rate when breathlessness develops) were measured during a progressive treadmill test to fatigue or symptom-limited maximum. The Profile Of Mood States questionnaire (POMS) was used to quantify subjective feelings of fatigue and vigour. Morning fasting levels of GH and IGF-I were measured using immunoassay of serum samples.

RESULTS

SPW speed at a fast pace of 1.69 +/- 0.18 m/s was achieved with higher than normal HR (112 +/- 15/min; normal = 102) and RPE (2.4 +/- 1.2). Similar to GH-deficient adults, VO2max (22.6 +/- 6.4 ml.kg-1.min-1; normal approximately 30 ml.kg-1.min-1) and VeT (13.1 +/- 2.9 ml.kg-1.min-1; predicted normal approximately 16 ml.kg-1(min-1) were low. However, VeT occurred at a normal fraction of VO2max (VeT/VO2max = 0.58). VeT was significantly increased and plasma IGF-I levels reduced following 3 and 6 months of octreotide LAR(R) treatment. Reduction in circulating IGF-I levels was correlated with improvement in reported vigour (r = 0.85) and VeT (r = 0.65) (P < 0.05).

CONCLUSIONS

Our findings demonstrate impairment in physical function and physical capacity consistent with the perception of increased fatigue among acromegalic patients. These objective measures of compromised physical function are similar to the changes that we have reported previously in adults with GH deficiency. Taken together, these data suggest that a narrow window for GH/IGF-I levels is required to maintain optimal physical function.

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

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

Fluorine-18 FDG myocardial positron emission tomographic findings before and after pituitary adenoma resection in a patient with acromegalic cardiomyopathy

Because of persistently elevated growth hormone levels, acromegaly gives rise to various changes in organs mediated by insulin-like growth factor-I. In the heart, it causes myocardial hypertrophy, and, with time, heart failure. The authors performed pituitary adenomectomy in a patient with acromegalic cardiomyopathy who had heart failure; after operation, the blood growth hormone levels decreased to within the normal range and there was a marked improvement in left ventricular function by gated blood pool scintigraphy. Pre- and postoperative fluorine-18 fluorodeoxyglucose (FDG) myocardial positron emission tomography showed increased accumulation of FDG in the myocardium before surgery, but accumulation within the normal range after operation. Myocardial glucose metabolism changed when the long-term effects of growth hormone and insulin-like growth factor-I were eliminated, and this appears to be accurately reflected by FDG positron emission tomography.

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

A group of 13 acromegalic patients was treated with lanreotide for 18 months and followed-up echocardiographically; these patients showed significant correlations between the decrease of both growth hormone (GH) and insulin-like growth factor-1 and the decrease of left ventricular mass index. This documents a regression of left ventricular hypertrophy in acromegaly after lanreotide treatment, the degree of which is dependent on the magnitude of the decrease of GH and insulin-like growth factor-1 serum levels.