Clinical and echocardiographic comparison of patients with the carcinoid syndrome with and without carcinoid heart disease

What Is Carcinoid Syndrome? A Critical Appraisal of Its Proposed Mediators

Carcinoid syndrome (CS) is a debilitating disease that affects approximately 20% of patients with neuroendocrine neoplasms (NEN). Due to the increasing incidence and improved overall survival of patients with NEN over recent decades, patients are increasingly suffering from chronic and refractory CS symptoms. At present, symptom control is hampered by an incomplete understanding of the pathophysiology of this syndrome. This systematic review is the first to critically appraise the available evidence for the various hormonal mediators considered to play a causative role in CS. Overall, evidence for the putative mediators of CS was scarce and often of poor quality. Based on the available literature, data are only sufficient to agree on the role of serotonin as a mediator of CS-associated diarrhea and fibrosis. A direct role for tachykinins and an indirect role of catecholamines in the pathogenesis of CS is suggested by several studies. Currently, there is insufficient evidence to link histamine, bradykinin, kallikrein, prostaglandins, or motilin to CS. To summarize, available literature only sufficiently appoints serotonin and suggests a role for tachykinins and catecholamines as mediators of CS, with insufficient evidence for other putative mediators. Descriptions of CS should be revised to focus on these proven hormonal associations to be more accurate, and further research is needed into other potential mediators.

A systematic review and meta-analysis of the diagnosis and surgical management of carcinoid heart disease

Introduction

Carcinoid heart disease (CHD), a complication of carcinoid syndrome (CS), is a rare condition that can lead to right sided valvular heart disease and has been traditionally associated with a poor prognosis. We conducted a systematic review and meta-analysis to explore the accuracy of biomarkers and echocardiography in diagnosing CHD amongst patients who are already known to have neuroendocrine tumours and to assess whether surgical management of CHD leads to a reduction in mortality.

Methods

A systematic literature search of MEDLINE, EMBASE, EBM Reviews, Google Scholar, ClinicalTrials.gov was conducted. All studies on patients with carcinoid heart disease (CHD) reporting on biomarkers, echocardiographic and surgical outcomes were included. The National Heart, Lung, and Blood Institute quality assessment tool was used to assess the methodological study quality. Data analysis was performed using Stata Statistical Software and R Studio, and individual meta-analyses were performed for biomarkers, echocardiographic findings, and surgical outcomes.

Results

A total of 36 articles were included in the systematic review analysis. N terminal pro-brain natriuretic peptide (NTproBNP) and 5-hydroxyindole acetate (5-HIAA) levels were higher in patients with CHD compared with those without CHD. 32% of CS patients had echocardiographic evidence of cardiac involvement, of which 79% involved tricuspid valve abnormalities. Moderate-severe tricuspid regurgitation was the most common echocardiographic abnormality (70% of patients). However, these analyses had substantial heterogeneity due to the high variability of cardiac involvement across studies. Pooled surgical mortality for CHD was 11% at 1 month, 31% at 12 months and 56% at 24 months. When assessing surgical outcomes longitudinally, the one-month surgical results showed a trend towards more recent surgeries having lower mortality rates than those reported in earlier years, however this was not statistically significant.

Discussion

There is not enough data in current literature to determine a clear cut-off value of NTproBNP and 5-HIAA to help diagnose or determine CHD severity. Surgical management of CHD is yet to show significant mortality benefit, and there are no consistent comparisons to medical treatment in current literature.

Analysis of Patients with NET G1/G2 Neuroendocrine Tumors of the Small Intestine in the Course of Carcinoid Heart Disease-A Retrospective Study

Neuroendocrine neoplasms of the small intestine (SI-NENs) are one of the most commonly recognized gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs). Carcinoid heart disease (CHD) is the primary cause of death in patients with the carcinoid syndrome (CS). The aim of this retrospective study was to evaluate possible factors impacting upon overall survival (OS) in subjects with both neuroendocrine tumors (NETs) G1/G2 of the small intestine (SI-NET) and CHD. Enrolled in our study of 275 patients with confirmed G1/G2 SI-NET, were 28 (10%) individuals with CHD. Overall survival was assessed using the Kaplan-Meier method. The Cox-Mantel test was used to determine how OS varied between groups. A Cox proportional hazards model was used to conduct univariate analyses of predictive factors for OS and estimate hazard ratios (HRs). Of the 28 individuals with confirmed carcinoid heart disease, 12 (43%) were found to have NET G1 and 16 (57%) were found to have NET G2. Univariate analysis revealed that subjects with CHD and without resection of the primary tumor had a lower OS. Our retrospective study observed that patients who presented with CHD and without resection of primary tumor had worse prognosis of survival. These results suggest that primary tumors may need to be removed when feasible, but further research is needed. However, no solid recommendations can be issued on the basis of our single retrospective study.

Carcinoid Heart Disease: a Review

PURPOSE OF REVIEW

The development of carcinoid heart disease (CHD) is a fibrotic complication of neuroendocrine neoplasms (NEN) which is associated with a poor prognosis. This review aims to summarise the clinical features, investigations and management of this condition.

RECENT FINDINGS

CHD can affect up to 50% of NET patients with carcinoid syndrome. However, it is often not screened for appropriately and recognised late when patients become symptomatic. A screening strategy with biomarkers and multimodality imaging is necessary for early recognition. Management by an experienced multidisciplinary team with appropriate medical therapeutic strategies and where indicated surgical intervention is needed to optimise clinical outcomes. CHD is a poor prognostic factor, but recently, outcomes have improved due to the multidisciplinary approach and centralised care of CHD-NET patients.

Carcinoid Heart Disease: Prognostic Value of 5-Hydroxyindoleacetic Acid Levels and Impact on Survival: A Systematic Literature Review

BACKGROUND

Carcinoid heart disease (CHD) can develop in patients with carcinoid syndrome (CS), itself caused by overproduction of hormones and other products from some neuroendocrine tumours. The most common hormone is serotonin, detected as high 5-hydroxyindoleacetic acid (5-HIAA). This systematic literature review summarises current literature on the impact of CHD on survival, and the relationship between 5-HIAA levels and CHD development, progression, and mortality.

METHODS

MEDLINE, Embase, Cochrane databases, and grey literature were searched using terms for CHD, 5-HIAA, disease progression, and mortality/survival. Eligible articles were non-interventional and included patients with CS and predefined CHD and 5-HIAA outcomes.

RESULTS

Publications reporting on 31 studies were included. The number and disease states of patients varied between studies. Estimates of CHD prevalence and incidence among patients with a diagnosis/symptoms indicative of CS were 3-65% and 3-42%, respectively. Most studies evaluating survival found significantly higher mortality rates among patients with versus without CHD. Patients with CHD reportedly had higher 5-HIAA levels; median urinary levels in patients with versus without CHD were 266-1,381 versus 67.5-575 µmol/24 h. Higher 5-HIAA levels were also found to correlate with disease progression (median progression/worsening-associated levels: 791-2,247 µmol/24 h) and increased odds of death (7% with every 100 nmol/L increase).

CONCLUSIONS

Despite the heterogeneity of studies, the data indicate that CHD reduces survival, and higher 5-HIAA levels are associated with CHD development, disease progression, and increased risk of mortality; 5-HIAA levels should be carefully managed in these patients.

Carcinoid Heart Disease: a Comprehensive Review

PURPOSE OF REVIEW

Carcinoid heart disease is a rare disorder that is associated with significant morbidity and mortality. In this review of the literature, we will present current concepts in diagnosis and management of carcinoid heart disease.

RECENT FINDINGS

Recent expert consensus guidelines highlight the role of echocardiography and screening with NT-proBNP for the evaluation of carcinoid heart disease. Advances in medical therapy along with better surgical outcomes highlight the experience and expertise that has been gained in the treatment of carcinoid heart disease. Carcinoid heart disease occurs in patients with neuroendocrine tumors who have carcinoid syndrome. Serotonin appears to play a central role in the development of carcinoid heart disease. Cardiac biomarkers and multimodality imaging can be used to aid in screening and diagnosis. The mainstay of treatment of carcinoid heart disease is surgery.

High tumour burden, delayed diagnosis and history of cardiovascular disease may be associated with carcinoid heart disease

Background

Patients with carcinoid syndrome (CS) may present carcinoid heart disease (CHD) but prognostic factors are not entirely understood.

Patients and Methods

Retrospective study of patients with metastatic neuroendocrine tumours (NETs) and CS and/or abnormal 24-hour-urinary 5-hydroxiindolacetic acid. CHD was defined as moderate to severe tricuspid or pulmonary regurgitation in the echocardiogram.

Results

The frequency of CHD among 42 patients was 38% (95% confidence interval [CI]: 23%-54%). CHD was associated with higher volume of liver metastases (odds ratio [OR] 13.86, 95% CI: 2.57-74.68, p = 0.002). Time from CS symptoms to NET diagnosis was borderline significant (p = 0.08). When CHD was defined as at least mild tricuspide regurgitation, the frequency of CHD was 45% and it was associated with cardiovascular comorbidities (OR: 6.58, 95% CI: 1.09; 39.78, p = 0.040).

Conclusion

CHD was frequent among patients with CS, significantly associated with high liver tumour burden, and likely linked to the history of cardiovascular disease and longer time of CS.

Diagnosing and Managing Carcinoid Heart Disease in Patients With Neuroendocrine Tumors: An Expert Statement

Carcinoid heart disease is a frequent occurrence in patients with carcinoid syndrome and is responsible for substantial morbidity and mortality. The pathophysiology of carcinoid heart disease is poorly understood; however, chronic exposure to excessive circulating serotonin is considered one of the most important contributing factors. Despite recognition, international consensus guidelines specifically addressing the diagnosis and management of carcinoid heart disease are lacking. Furthermore, there is considerable variation in multiple aspects of screening and management of the disease. The aim of these guidelines was to provide succinct, practical advice on the diagnosis and management of carcinoid heart disease as well as its surveillance. Recommendations and proposed algorithms for the investigation, screening, and management have been developed based on an evidence-based review of the published data and on the expert opinion of a multidisciplinary consensus panel consisting of neuroendocrine tumor experts, including oncologists, gastroenterologists, and endocrinologists, in conjunction with cardiologists and cardiothoracic surgeons.

Complications from carcinoid syndrome: review of the current evidence

Patients with well-differentiated neuroendocrine tumours may develop carcinoid syndrome (CS), which is characterised by flushing, abdominal cramps, diarrhoea, and bronchospasms. In this scenario, long-term secretion of vasoactive substances—serotonin, tachynins, and others, may induce fibrogenic responses in local or distant tissues, leading to complications such as carcinoid heart disease (CHD), mesenteric and/or retroperitoneal fibrosis. Rare cases of lung/pleural fibrosis and scleroderma have also been described. Despite it not being well described yet, current evidence suggests the pathogenesis of such fibrogenic complications relies on signalling through 5-HT_2B and TGF-β1. Medical management is still very limited and lacks prospective and randomised studies for definitive recommendations. Surgical procedures remain the best definitive treatment option for CHD and abdominal fibrosis. Recently, cognitive impairment has also been described as a potential consequence of CS. This review critically discusses the literature concerning the epidemiology, pathogenesis, clinical features, diagnosis, and treatment options for CS-related long-term complications.

Carcinoid syndrome and perioperative anesthetic considerations

Carcinoid tumors are uncommon, slow-growing neoplasms. These tumors are capable of secreting numerous bioactive substances, which results in significant potential challenges in the management of patients afflicted with carcinoid syndrome. Over the past two decades, both surgical and medical therapeutic options have broadened, resulting in improved outcomes. The pathophysiology, clinical signs and symptoms, diagnosis, treatment options, and perioperative management, including anesthetic considerations, of carcinoid syndrome are presented.

Echocardiographic follow-up of treated patients with carcinoid syndrome

Carcinoid heart disease is a rare disease, and its prevalence is uncertain. The aim of the present prospective study was to assess the prevalence of carcinoid heart disease using annual echocardiographic follow-up. We studied 80 consecutive patients presenting with histologically proven digestive endocrine tumor and carcinoid syndrome. All patients underwent annual conventional transthoracic echocardiographic studies and measurement of biologic carcinoid markers. Right- and left-sided carcinoid heart disease and the score of the severity of carcinoid heart disease were systematically assessed. At baseline, the prevalence of right- and left-sided carcinoid heart disease was 33% and 8%, respectively. At the end of follow-up, the corresponding prevalence was 53% and 21%. The correlations were strong between urinary 5-hydroxyindoleacetic acid (5-HIAA) and the right-sided carcinoid heart disease score (r = 0.75, p <0.0001), between urinary 5-HIAA and the left-sided carcinoid heart disease score (r = 0.83, p = 0.001), and between urinary 5-HIAA and the overall carcinoid heart disease score (r = 0.84, p <0.0001). All patients with > or =3 years of carcinoid syndrome and increased level of urinary 5-HIAA presented with echocardiographic evidence of valve disease on routine monitoring. In conclusion, the prevalence of carcinoid heart disease remained high and increased during follow-up. Carcinoid heart disease progresses over time, highlighting the need for echocardiographic follow-up once carcinoid syndrome has been diagnosed.

Carcinoid heart disease

The carcinoid syndrome is usually evident when enterochromaffin (EC) cell-derived neuroendocrine tumors (carcinoids) metastasize to the liver. In addition to carcinoid symptomatology, about 40% of patients exhibit carcinoid heart disease (CHD) with fibrotic endocardial plaques and associated heart valve dysfunction. The mechanism behind CHD development is not fully understood, but serotonin (5-HT) is considered to be a major initiator of the fibrotic process. Most patients present with right-sided heart valve dysfunction since pulmonary and tricuspid valves lesions are the most common (>95%) cardiac pathology. Left-sided valvular involvement, and angina associated with coronary vasospasm occur in ~10% of subjects with CHD. Pathognomonic echocardiograpic features include immobility of valve leaflets and thickening and retraction of the cusps most commonly resulting in tricuspid valve regurgitation and pulmonary stenosis. Therapeutic options include cardioactive pharmacotherapy for heart failure and, in selected individuals, cardiac valve replacement. Previously valve replacement was reserved for advanced disease due to a perioperative mortality of >20% however in the last decade, technical advances as well as an earlier diagnosis have decreased surgical mortality to <10% and valve replacements are undertaken more frequently. A recent analysis of 200 cases demonstrated an increase in median survival from 1.5 years to 4.4 years in the last two decades. Although the improved prognosis might also reflect the increased use of surgical cytoreduction, hepatic metastatic ablative therapies and somatostatin analogs a robust correlation between diminution of circulating tumor products and an increased long-term survival in CHD has not been rigorously demonstrated.

Analysis of 150 patients with carcinoid syndrome seen in a single year at one institution in the first decade of the twenty-first century

Carcinoid heart disease (CHD), reported in 50% to 70% of patients with carcinoid syndrome, is thought to be related to the production of 5-hydroxytryptamine by the tumor. The development of new therapeutic modalities designed to reduce tumor hormone production may have altered the development of CHD. Currently, echocardiography is performed when clinical suspicion of CHD exists. The aim of this study was to establish the prevalence of CHD in the setting of modern treatment regimens and delineate whether a screening program for CHD is needed. One hundred fifty patients with carcinoid syndrome were screened for CHD by transthoracic echocardiography. The functional status of patients was classified according to New York Heart Association class. Thirty patients (20%) were found to have CHD. Of those with CHD, 14 (47%) had left- and right-sided valvular lesions. Patent foramen ovale was present in all patients with left-sided CHD. Forty-three percent of patients were in New York Heart Association class I, 40% in class II, 13% in class III and 3% in class IV. Eight patients (27%) with moderate or severe valvular lesions were in class I. Thirty-seven percent of patients with CHD had no physical signs. In conclusion, the presence of symptoms or abnormalities on clinical examination has a low sensitivity for the presence of CHD. Therefore, screening with echocardiography, even in patients who are asymptomatic, should be advocated.

Carcinoid heart disease

Carcinoid heart disease is a rare form of valvular heart disease. The management of these patients is complex, as the systemic malignant disease and the cardiac involvement have to be considered at the same time. Progress in the treatment of patients with carcinoid disease has resulted in improved symptom control and survival. Development and progression of carcinoid heart disease are associated with increased morbidity and mortality. In patients with severe cardiac involvement and well-controlled systemic disease, cardiac surgery has been recognized as the only effective treatment option. Valve replacement surgery may not only be beneficial in terms of symptom relief, but may also contribute to the improved survival observed over the past 2 decades in patients with carcinoid heart disease. Early diagnosis and early surgical treatment in appropriately selected patients may provide the best results. In this article, we review the current literature regarding the biology, diagnosis, treatment, and prognosis of carcinoid heart disease.

Cardiac MRI Is an Important Complementary Tool to Doppler Echocardiography in the Management of Patients with Pulmonary Regurgitation

Cardiac MRI (CMR) is a noninvasive diagnostic tool with comprehensive capabilities similar to that of two-dimensional echocardiography with Doppler. In addition to the ability to evaluate the etiology and severity of pulmonary valve regurgitation (PR), CMR is well designed to serially monitor the impact of the PR on the right ventricle (RV). Importantly, RV dilation and dysfunction is a critical determinate to time surgical intervention. CMR gives the silent RV, suffering from PR, a voice.

Assessment of patent foramen ovale in carcinoid heart disease

BACKGROUND AND OBJECTIVE

Carcinoid syndrome may involve right carcinoid heart disease (CHD), secondary to the release of vasoactive substances. Left CHD is rare, as the inactivation of serotonin by the lung protects the left heart. We attempted to evaluate the prevalence of CHD and patent foramen ovale (PFO) with serial contrast transthoracic echocardiographic studies and to determine the markers of right and left CHD progression.

METHODS

Forty-one consecutive patients with proved digestive endocrine tumor and carcinoid syndrome were prospectively enrolled. All patients underwent serial conventional and contrast transthoracic echocardiographic studies. Right and left CHD, PFO, radiological examinations, and biological carcinoid markers were systematically assessed.

RESULTS

Left CHD was present in 5 patients at baseline and in 13 patients (32%) during follow-up (P = .03). The 13 patients with left CHD also had PFO, and no left CHD occurred without PFO (P < .0001). Right CHD was present in 16 patients (39%) at baseline and in 25 patients (61%) at the end of follow-up (P = .04). The prevalence of right and left CHD was significantly higher in patients with PFO (88% and 76%, respectively; P < .04). A progression of right and left CHD was present, respectively, in 19 and 9 patients but was mainly found in patients with PFO (15 and 9 patients; P < .0001). The main marker of CHD progression was the presence of PFO (odds ratio 44.2, 95% confidence interval 4.4-447.7; P = .001).

CONCLUSIONS

PFO is a new marker of CHD progression and should be systematically assessed with routine contrast transthoracic echocardiography in patients with carcinoid syndrome to determine patients at high risk of CHD progression.

A mouse model of carcinoid syndrome and heart disease

BACKGROUND

Carcinoid heart disease occurs in over 65% of patients with the carcinoid syndrome and is characterized by fibrous thickening of cardiac valves, leading to heart failure. Whether serotonin is directly responsible for these cardiac abnormalities is unknown. Therefore, to further understand the etiology and pathophysiology of carcinoid heart disease, we developed an animal model of the carcinoid syndrome.

MATERIALS AND METHODS

Seventeen nude mice underwent intrasplenic injection of human pancreatic carcinoid BON cells (10(7)) and then were euthanized 9 weeks later. Murine livers were analyzed by immunohistochemistry. Murine hearts were sectioned and the surface area of the right heart valves determined. Blood was also collected and analyzed for platelet serotonin by ELISA.

RESULTS

Sixty-five percent of the mice developed gross carcinoid liver metastases demonstrated by chromogranin-A-staining lesions within the liver. Mice with carcinoid liver metastases had elevated platelet serotonin levels (1058 +/- 529 ng/ml versus 123 +/- 52 ng/ml, P = 0.002) when compared to the controls. Animals with carcinoid liver metastases also had a trend toward greater tricuspid valvular surface areas (242 +/- 24 versus 174 +/- 25 microm, P = 0.08). On histological examination, this increase in tricuspid surface area in mice with liver metastases appeared to be due to fibrosis of the valvular tissues, consistent with the pathologic findings of carcinoid heart disease.

CONCLUSIONS

Using this novel animal model of carcinoid syndrome, the tricuspid valve thickening resembling carcinoid heart disease could be due to exposure to factors such as serotonin secreted by carcinoid tumor cells.

Cardiac metastasis from carcinoid tumour: magnetic resonance imaging findings

A case of myocardial metastasis from a gastrointestinal carcinoid is presented. The colon was the primary site. The patient did not manifest symptoms of carcinoid syndrome and had no echocardiographic or MRI evidence of carcinoid valvular heart disease.

Carcinoid tumors and fibrosis: an association with no explanation

Carcinoid tumors are slow-growing neuroendocrine neoplasms most commonly associated with the gut and broncho-pulmonary system. In many instances, they are identified at surgery for unexplained bowel obstruction or during exploration of the small bowel in search of a primary tumor once distant metastases have been detected. Carcinoid tumors of the small bowel often present with pronounced fibrosis in the peri-tumoral tissues, distant in the heart or lungs, and locally in the peritoneal cavity. Despite medical and therapeutic advances that have alleviated symptoms and prolonged life, a substantial subset of patients develops mesenteric and small bowel carcinoid fibrosis and/or carcinoid heart disease. Fibrosis, and increasingly cardiac heart disease, are important components of intestinal carcinoid disease and are of considerable clinical concern, as both of these conditions reflect a connective tissue disorder whose etiology, biology, and therapy are unknown. In the past, individuals with carcinoid disease died of metastasis and uncontrollable symptomatology. Currently, there exists no clinical method to determine the development of fibrosis and little is understood about the biological basis of fibrosis. The elucidation of the biology and management of fibrosis is thus an issue of paramount clinical and scientific importance in determining appropriate diagnostic and therapeutic strategy. Therefore, the unraveling of the molecular events indicative of fibrosis in these cells and the identification of appropriate therapeutic targets is of considerable patient-care relevance. We have surveyed the world literature over the past 40 yr to evaluate both the incidence of carcinoid processes and track the evolving understanding of this process. In addition, we have provided more current mechanistic information in regard to the biological basis of fibrosis associated with small bowel carcinoid tumors.

Complications of midgut carcinoid tumors and carcinoid syndrome

The carcinoid syndrome, associated with carcinoid tumors of the midgut, consists of symptoms such as diarrhea, flushing, wheezing and cardiovascular symptoms. This review focuses on these symptoms and discusses therapeutic options. The symptoms are caused by the secretion of biogenic amines, polypeptides and other factors of which serotonin is the most prominent. However, diarrhea is also due to factors such as malabsorption. Besides antitumor therapy, more specific interventions such as serotonin receptor blockers can be useful. The carcinoid heart disease involves the tricuspid and pulmonary valve. In the pathogenesis, serotonin plays a central role. The therapeutic approach is mostly symptomatic. Other cardiovascular complications include bowel ischemia and hypertension. Pellagra and psychiatric symptoms are due to a depletion of tryptophan, which is consumed by the carcinoid tumor for serotonin synthesis. Finally, follow-up and clinical practice of patients with carcinoid tumors are discussed.

Carcinoid heart disease: an update

BACKGROUND

Carcinoid tumours are a poorly defined collection of lesions, histopathologically indistinguishable from gastroentero-pancreatic neuroendocrine tumours. In this report, we discuss epidemiology and survival, clinical presentation, carcinoid valvular heart disease (CVHD), histopathological considerations and treatment options.

METHODS

Review and update of the literature.

RESULTS

The term carcinoid suggests a disease entity, but with increasing knowledge it becomes progressively confusing. To avoid further confusion, it is advisable to define these tumours using differentiation, stage, primary site, known tumour products and an associated clinical syndrome. Incidence varies between 0.8 and 1.9/100,000 population. About 20% present with metastases, with a 5-year survival varying between 15% and 35%. Metastatic disease frequently accompanies the carcinoid syndrome (flushing, diarrhoea, wheezing and CVHD). CVHD incidence is about 50%, and seems unrelated to disease duration and tumour mass. An aetiological relation of CVHD with urinary 5-HIAA remains to be confirmed. Resection is the only curative option. Surgery can also offer prolonged palliation and is needed to restore bowel transit in obstructive/ischaemic bowel problems. Adequate palliation of hormone-related symptoms can also be achieved by somatostatin analogues, meta-iodo-benzyl-guanidine preparations and interferon-alpha formulations, all with a 70% response rate. Embolization of liver metastases has led to objective responses in about 50% of patients, but is accompanied by significant side effects.

CONCLUSIONS

Most patients are cured by surgery. Symptom relief is the main target in metastatic disease and can be achieved by a range of equally potent biologically active medications, debulking surgery and hepatic embolization.

Diet medications and valvular hearl disease: the current evidence

Since 1997, the appetite suppressant drugs fenfluramine-phentermine (fen-phen) and dexfenfluramine have been associated with the development of valvular heart disease. As a result, the drugs have been withdrawn from the market and interim recommendations for evaluation and treatment of exposed patients were issued. However, subsequent studies showed lower prevalence rates for valve abnormalities than were initially reported, and the possibility of such drug-induced lesions resolving has been raised. This article reviews relevant evidence and discusses concerns for the dental practitioner.

Carcinoid heart disease: a case report and literature review

We report a patient who presented for elective exploratory laparotomy, and resection of a pelvic mass, which was thought to be ovarian carcinoma. Intraoperative transesophageal echocardiography demonstrated right-sided valvular heart lesions, which suggested the diagnosis of carcinoid syndrome before a pathologic confirmation was obtained. This article discusses the classical presentation and anesthetic management of patients with carcinoid syndrome and emphasizes the importance of proper preoperative diagnosis and careful planning if the incidence and severity of the symptoms that this condition can provoke are to be reduced.

Prediction of prognosis by echocardiography in patients with midgut carcinoid syndrome

BACKGROUND

The association between malignant midgut carcinoid tumours and right-sided cardiac lesions is well known, but the pathogenetic link between tumour secretion and valvular disease is still obscure. The purpose of this investigation was to describe the morphological and functional changes of valvular heart disease in a large patient series and to correlate these findings with hormonal secretion and prognosis.

METHODS

Of 64 consecutive patients with the midgut carcinoid syndrome followed between 1985 and 1998, valvular heart disease was evaluated in 52 patients by two-dimensional echocardiography, Doppler estimation of valvular regurgitation and flow profiles. A majority was also evaluated with exercise electrocardiography and spirometry.

RESULTS

Structural and functional abnormalities of the tricuspid valve were found in 65 per cent of patients, while only 19 per cent had pulmonary valve regurgitation. Long-term survival was related to excessive urinary excretion of 5-hydroxyindole acetic acid of over 500 micromol in 24 h, but the main predictor of prognosis was the presence of severe structural and functional abnormalities of the tricuspid valve. Although advanced tricuspid abnormalities were prevalent in this series, only one patient died from right ventricular heart failure.

CONCLUSION

Tricuspid valvular disease is a common manifestation of the midgut carcinoid syndrome and advanced changes are associated with poor long-term survival. Active surgical and medical therapy of the tumour disease reduced the hormonal secretion and, combined with cardiological surveillance, made right ventricular heart failure a rare cause of death in these patients.

Nonsurgical closure of a patent foramen ovale in a patient with carcinoid heart disease and severe hypoxia from interatrial shunting

We report the percutaneous transcatheter closure of a patent foramen ovale using an Amplatzer septal occluder in a rare patient with carcinoid heart disease involving both the right and left heart who presented with severe hypoxemia secondary to intra-atrial shunting. We believe this is the first report of this technique being utilized in a patient with carcinoid heart disease and it may represent an alternative to surgical closure in these patients at high risk for surgical complications.

The acute effects of dexfenfluramine on human and porcine pulmonary vascular tone and resistance

STUDY OBJECTIVES

Treatment with anorectics has become an important aspect of care for the severely obese. One such anorectic, the phenylethylamine dexfenfluramine (dFen), has been associated with the development of pulmonary hypertension. It works by reducing the neuronal uptake of 5-hydroxytryptamine (5-HT; serotonin) through inhibition of the 5-HT transporter. In this study we investigated whether dFen has a direct vasoconstrictor action on human and porcine pulmonary vasculature.

DESIGN

For the human study, tissue was obtained from patients who had undergone lung and heart-lung transplantation. The effect of dFen was studied in seven isolated colloid perfused human lungs and in rings of human pulmonary artery (PA) dissected from the lungs of a further 19 patients. For the porcine study, regional pulmonary vascular resistances (PVRs) were measured in isolated perfused porcine lungs. Vasoconstriction was assessed following dFen alone and in combination with hypoxia, cyclo-oxygenase blockade (indomethacin, 10(-5) mol/L), or nitric oxide synthase (NOS) blockade (N(G)-nitro-L-arginine, 10(-5) mol/L).

RESULTS

In the human study, 5-HT and dFen caused only limited increases in tension of isolated rings of PA. The concentration of dFen, 10(-4) mol/L, that was needed to increase tension was higher than that found normally in treated patients where peak levels are 3. 3 x 10(-7) mol/L. Other vasoconstrictors such as prostaglandin F(2)alpha, 10(-5) mol/L, and the thromboxane analog U46619, 10(-6) mol/L, produced far greater increases in tension. Ketanserin, 10(-4) mol/L, attenuated the constrictor response to 5-HT but had no effect on the constrictor response to dFen. Removal of the endothelium did not influence the response to dFen. In the isolated ventilated and perfused lungs, dFen caused an increase in PVR again only at a comparatively high concentration, 10(-4) mol/L. In the porcine study, dFen, 10(-4) mol/L, did not increase any PVR during normoxia or following NOS blockade. Small insignificant increases in PVR occurred during hypoxia and after cyclo-oxygenase blockade.

CONCLUSION

These results do not support the view that dFen would act as a direct vasoconstrictor when given in the usual doses. However, delayed elimination of dFen could raise tissue concentrations to high levels and give rise to vasoconstriction and pulmonary hypertension.

Echocardiographic and biochemical evaluation of the development and progression of carcinoid heart disease

OBJECTIVES

To study the applicability of a newly developed echocardiographic scoring system in the assessment of carcinoid valvular heart disease.

BACKGROUND

We investigated prospectively the development, progression and regression of carcinoid valvular heart disease in patients with carcinoid syndrome by serial echocardiography, correlating these features with urinary 5-HIAA levels and clinical data collected during therapy with somatostatin analog.

METHODS

Twenty-three patients with carcinoid syndrome underwent serial echocardiographic examinations. An echocardiographic carcinoid valvular heart disease (CVHD) % score was determined from points assigned for tricuspid and pulmonary valve structure and function.

RESULTS

Fifteen patients had no CVHD at study entry (group 1), while 8 patients had findings of CVHD (group 2). Five patients in group q developed new CVHD (1B), while one demonstrated progression of CVHD (2B). The remaining patients did not develop (1A) or had no progression of CVHD (2B). Despite major declines in 5-HIAA levels during therapy in most patients, CVHD did not regress. There were significantly lower levels of median baseline 5-HIAA (98.8 vs. 256 mg/24 h), posttreatment 5-HIAA (50.3 vs. 324 mg/24 h) and posttreatment 5-HIAA time integral (37.3 vs. 192 g/24 h* days) in group A vs. B (p < 0.05). However, only posttreatment 5-HIAA levels independently predicted the development or progression of CVHD by multiple step-wise regression analysis (p < 0.005), with a threshold observed in the 100 mg/24 h range.

CONCLUSIONS

We designed a new echocardiographic scoring system to evaluate CVHD. Correlating echocardiographic scores with biochemical and clinical markers showed that only posttreatment 5-HIAA levels independently predicted the development or progression of CVHD. This study strengthens the association between serotonin secretion and CVHD, as well as introducing a new technique for serial follow-up of these patients.

Tricuspid valve disease. Clinical evaluation, physiopathology, and management

The tricuspid and mitral valves are homologous whose function depends on coordination among components. Isolated tricuspid valve abnormalities are relatively uncommon. Rheumatic disease, chemicals, immunologic and degenerative disorders alter leaflet anatomy and may result in either stenosis, insufficiency or a combination. More often, tricuspid disorders present as a component of congenital syndromes or secondary to pulmonary vascular or let heart disease which alter geometry and function of nonleaflet components.

Carcinoid heart disease. Correlation of high serotonin levels with valvular abnormalities detected by cardiac catheterization and echocardiography

BACKGROUND

Although serotonin has been postulated as an etiologic agent in the development of carcinoid heart disease, no direct evidence for different ambient serotonin levels in cardiac and noncardiac patients has been reported to date.

METHODS AND RESULTS

The present study reviews our experience with 604 patients in the Duke Carcinoid Database. Nineteen patients with proven carcinoid heart disease (by cardiac catheterization and/or echocardiogram) were compared with the remaining 585 noncardiac patients in the database with regard to circulating serotonin and its principal metabolite, 5-hydroxyindole acetic acid (5-HIAA). No significant demographic differences existed between the cardiac and noncardiac groups; however, typical carcinoid syndrome symptoms (ie, flushing and diarrhea) were almost threefold more common in the cardiac group (P < .001). Compared with the noncardiac group, heart disease patients demonstrated strikingly higher (P < .0001) mean serum serotonin (9750 versus 4350 pmol/mL), plasma serotonin (1130 versus 426 pmol/mL), platelet serotonin (6240 versus 2700 pmol/mg protein), and urine 5-HIAA (219 versus 55.3 mg/24 h) levels. The spectrum of heart disease among the 19 patients showed a strong right-sided valvular predominance, with tricuspid regurgitation being the most common valvular dysfunction (92% by cardiac catheterization; 100% by echocardiogram).

CONCLUSIONS

These data suggest that serotonin plays a major role in the pathogenesis of the cardiac plaque formation observed in carcinoid patients.

Carcinoid heart disease. Clinical and echocardiographic spectrum in 74 patients

BACKGROUND

The carcinoid syndrome is a rare cause of acquired valvular heart disease. Although the typical echocardiographic features of carcinoid heart disease are well recognized, this large series provides new information about unusual manifestations of the disease as well as the role of Doppler echocardiography.

METHODS AND RESULTS

Between 1980 and 1989, 132 patients with carcinoid syndrome underwent echocardiographic study. The echocardiographic, Doppler, and clinical features of the 74 patients (56%) with echocardiographic evidence of carcinoid heart disease are described. Among these patients, 97% had shortened, thickened tricuspid leaflets. Tricuspid regurgitation was present in all 69 patients with carcinoid heart disease who underwent Doppler examination, and it was of moderate or severe degree in 62 patients (90%). Severe tricuspid regurgitation was characterized by a dagger-shaped Doppler spectral profile with an early peak pressure and rapid decline. The pressure half-time was prolonged (mean, 116 msec), which is consistent with associated tricuspid stenosis. The pulmonary valve appeared thickened, retracted, and immobile in 36 patients (49%) and was diminutive to the extent of not being visualized in an additional 29 patients (39%). Among the 47 patients who underwent Doppler evaluation of the pulmonary valve, regurgitation was present in 81%, and stenosis was present in 53%. Left-sided valvular involvement was present in five patients (7%), four of whom had patent foramen ovale or carcinoid tumor involving the lung. Previously undescribed myocardial metastases were present in three patients (4%) and were confirmed by biopsy in each case. Small pericardial effusions were present in 10 patients (14%). Patients with and without echocardiographic evidence of carcinoid heart disease did not differ with regard to sex, age, location of the primary tumor, duration of diagnosis, or duration of symptoms of carcinoid syndrome. However, the mean pretreatment level of urinary 5-hydroxyindoleacetic acid was higher in patients with carcinoid heart disease than in patients without carcinoid heart disease (270 versus 131 mg/24 hrs, p < 0.001). The symptom of dyspnea was more prevalent among patients with carcinoid heart disease than in patients without the disease (54% versus 27%, p = 0.003); as expected, heart murmurs were also noted more frequently in patients with disease (92% versus 43%, p < 0.0001). Treatment regimens and response to therapy were similar in the two groups. Survival of patients with echocardiographic evidence of carcinoid heart disease was reduced compared with those without cardiac involvement (p = 0.0003). ECG and chest roentgenographic findings in patients with carcinoid heart disease were nonspecific.

CONCLUSIONS

The broad spectrum of carcinoid heart disease is detailed in this large series. This includes not only right-sided valvular lesions but also left-sided involvement, pericardial effusion, and myocardial metastases.

Failure of balloon dilatation of the pulmonary valve in carcinoid pulmonary stenosis

BACKGROUND

Carcinoid heart disease typically results in pulmonary stenosis and tricuspid incompetence. Percutaneous balloon dilatation is an effective treatment for congenital pulmonary stenosis and has been applied successfully to tricuspid stenosis caused by carcinoid heart disease. The value of balloon dilatation of the pulmonary valve in carcinoid pulmonary stenosis was assessed.

METHODS

Two patients with severe congestive heart failure secondary to carcinoid heart disease and with documented pulmonary stenosis had balloon dilatation of the pulmonary valve. In both cases tricuspid regurgitation was also present together with reduced cardiac output.

RESULTS

The procedure was technically successful in both patients. One patient experienced symptomatic benefit for two months and the other experienced no improvement. Both patients subsequently required combined tricuspid and pulmonary valve replacement from which good results and symptomatic improvement were obtained.

CONCLUSION

Though balloon dilatation of the pulmonary valve is technically feasible it is unlikely to provide useful palliation in carcinoid heart disease. Valve surgery should be considered in patients in whom the malignancy is controlled but carcinoid heart disease is producing drug resistant congestive heart failure.

Bronchial neuroendocrine (carcinoid) tumor causing unilateral left-sided carcinoid heart disease

A female patient suffering from a bronchial neuroendocrine tumor with unilateral left-sided carcinoid heart disease is reported. Repeated x-ray films of the chest showed a slowly growing lung tumor in the left lower lobe. The patient refused any diagnostic or therapeutic procedure to define the type of the tumor. During the follow-up of 24 years she developed severe mitral and moderate to severe aortic insufficiency, both invasively quantified by thermodilution techniques. During surgery for double valve replacement the patient died from left ventricular heart failure. Necropsy revealed the typical pattern of a bronchial neuroendocrine tumor without metastases. Examination of the heart disclosed the characteristic deposits of fibrous tissue on the cusps of both the mitral and the aortic valves whereas the right heart showed no abnormalities. Review of the literature suggests the unilateral left-sided carcinoid heart disease to be a very rare finding, its pathogenesis remains to be elucidated.