Carcinoid heart disease: early failure of an allograft valve replacement

Vigilance for carcinoid heart disease is still required in the era of somatostatin analogues: Lessons from a case series

AIM

Carcinoid heart disease (CHD) is a well-documented complication of neuroendocrine tumors (NETs) due to secreted hormones causing fibrosis. Somatostatin analogues (SSAs) can decrease hormonal secretion and inhibit tumor growth. The reported incidence of CHD has decreased as SSA use has increased. We describe a series of patients who have developed CHD even though they were treated with SSA therapy.

METHODS

Nine patients were seen in four centers in Australia and New Zealand. The average duration of follow-up from diagnosis was 39 months.

RESULTS

Three patients had Grade 1 and six Grade 2 disease by World Health Organization 2010 criteria. All patients had no CHD symptoms at baseline and started SSA therapy soon after diagnosis, yet developed significant, symptomatic cardiac dysfunction in their disease course. The median time from NET diagnosis to SSA initiation was 1 month, and median time from NET diagnosis to CHD diagnosis was 23 months (range 4-52). All patients who were tested had persistently increased hormonal levels (chromogranin A, urinary 5-hydroxyindolacetic acid).

CONCLUSIONS

The good symptomatic control afforded by SSAs should not lead to reduced vigilance in screening for CHD, especially in patients with persistently elevated hormonal assays. Clinicians should consider regular echocardiographic screening in patients with a secretory syndrome.

Bioprosthetic valve thrombosis in carcinoid heart disease

Tricuspid regurgitation in carcinoid syndrome leads to significant morbidity and mortality that may warrant a tricuspid valve replacement. However, for patients with high serotonin levels and known hypercoagulable risks, the optimum timing for surgery and postoperative anticoagulation approaches remain unclear. High serotonin-triggered hypercoagulability makes prosthetic valves susceptible to thrombosis. Despite appropriate management with a somatostatin analog, some patients continue to have high markers of serotonin that causes platelet aggregation and rapid clot formation. In severely symptomatic patients who require valve surgery, it may not be feasible to postpone surgery until these metabolites are normalized, which may add a substantial risk for postoperative valve thrombosis to an otherwise uneventful procedure. In some, there is a significant need to predict and prevent bioprosthetic valve thrombosis in carcinoid heart disease and to identify best anticoagulation practices across a spectrum of its complex coagulation dynamics and clinical presentation.

Quadruple Valve Replacement for Carcinoid Heart Disease

INTRODUCTION

Carcinoid heart disease most frequently involves the tricuspid or, more rarely, the pulmonary valve and presents with right heart failure as 5-HT is metabolized by the lung. Left-sided valve involvement is quite rare. We describe our experience of 3 patients presenting with heart failure secondary to carcinoid heart disease affecting all four cardiac valves. There are only four previous isolated case reports in the literature.

METHODS

All three patients underwent quadruple valve replacement during a single operation. Right ventricular outflow tract reconstruction with a pericardial patch was performed in all patients. For 24 hours prior to surgery, all patients received intravenous octreotide, which continued in intensive care for at least 24 hours.

RESULTS

Mean cross-clamp and bypass times were 175 (range 164-197 minutes) and 210 (range 195-229 minutes) minutes, respectively. Mean intensive treatment unit (ITU) and inpatient stays were 2.3 (range 2-3 days) and 12 (range 9-16 days) days, respectively. One patient was reopened for bleeding 4 hours postoperatively from a ventricular pacing wire site. None required a permanent pacemaker postoperatively. There were no other complications in any patient. The quality of life was excellent at 6-16 months clinic follow-up as they were in NYHA 1. Postoperative echocardiography showed no paravalvular leaks and well-functioning prostheses in all cases.

CONCLUSION

Surgery to replace all four valves is feasible with excellent medium-term survival and a very low rate of complications. Patients with carcinoid heart disease should always be considered for surgery irrespective of the extent of valvular involvement.

Valvular Disorders in Carcinoid Heart Disease

Carcinoid heart disease is a rare but important cause of intrinsic right heart valve disorders leading to right heart failure. Occasionally, left-sided heart valves may also be involved. The characteristic cardiac pathological findings of carcinoid heart disease are endocardial thickening as a result of fibrous deposits on the endocardium. Echocardiographic examination and right heart catheterization are very useful for the diagnosis of the lesion. If more cardiac valves are affected, multiple valve replacement should be considered. The management of the pulmonary valve lesion depends on the extent of the diseased valve, either by valvulotomy, valvectomy, or valve replacement. Percutaneous valve implantations in the pulmonary and in the inferior vena cava positions have been advocated for high-risk patients.

Cardiac Surgery for Carcinoid Heart Disease: A Weapon Not to Be Misused

Carcinoid heart disease (CHD) complicates approximately 25% of patients with a carcinoid tumor and carcinoid syndrome and leads to heart valve degeneration with mixed-stenotic and regurgitation pathology and consequent heart failure (HF) leading to significant morbidity and mortality. Cardiac surgery in symptomatic, severe CHD leads to significantly better functional capacity and prolonged survival when compared to medical treatment alone. Recent studies have shown improvement in postoperative outcomes of patients undergoing surgery for CHD over the last decades. The trend for early diagnosis and application of surgery prior to the manifestation of HF symptoms, which tended to develop during the previous years, does not seem justifiable based on the findings of recent studies. Therefore, the optimal timing of intervention in CHD and the type of valve that should preferably be used remain issues of controversy. This review comprehensively examines the existing literature on the treatment options for patients with CHD, with a special focus on short- and long-term survival after cardiac surgery, and discusses the selection of the exact patient profile and intervention timing that are more likely to optimize the benefit-to-risk ratio for surgical intervention.

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.

Cardiac manifestations of gastrointestinal carcinoid tumor

Carcinoid tumors are rare, slow-growing tumors found primarily in the GI tract. Carcinoid syndrome develops when vasoactive substances (particularly serotonin) released by carcinoid tumors gain access to the systemic circulation. Carcinoid heart disease develops in patients with carcinoid syndrome and is commonly associated with the development of right-sided valve dysfunction and signs of symptoms of right heart failure. Timely surgical intervention provides relief from symptoms and may improve survival. Management of these patients should be undertaken in a specialized center by a multidisciplinary team with appropriate expertise.

Carcinoid heart disease

Carcinoid tumors are rare, indolent neuroendocrine tumors that are often associated with a syndrome characterized by episodic flushing, secretory diarrhea, bronchospasm, and hypotension-the carcinoid syndrome. Cardiac involvement occurs in one-half to two-thirds of patients with carcinoid syndrome and is associated with a worse clinical outcome. Carcinoid heart disease is characterized by endocardial plaque-like deposits found predominantly on right-sided heart valves, leading to the combination of valvular stenosis and regurgitation. Left-sided cardiac involvement can also occur in <10% of patients. Somatostatin analogs form the therapeutic cornerstone in the medical management of these patients. Cytotoxic chemotherapy has had only limited success in the treatment of metastatic carcinoid tumors. Hepatic resection or palliative cytoreduction may be of benefit in patients with limited hepatic disease. Hepatic artery embolization is usually applied if a patient is not eligible for surgical debulking. The development and progression of carcinoid heart disease are associated with an unfavorable outcome. In those patients having severe cardiac involvement and well-controlled systemic disease, valve replacement surgery has been found to be an effective treatment that can both relieve intractable symptoms and contribute to improved clinical outcomes.

In patients with carcinoid syndrome undergoing valve replacement: will a biological valve have acceptable durability?

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was 'In patients with carcinoid syndrome undergoing valve replacement, will a biological valve have acceptable durability?' Altogether, more than 130 papers were found using the reported search, of which 17 represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. The pooled data from all papers represent 51 patients with carcinoid right heart disease who underwent tricuspid valve replacement. Two 'outcomes' studies reported a 30-day postoperative mortality of 16.7-18% and 2-year survival rates of 44 and 50%, respectively. Seventeen patients were detailed in case reports. Of these 17 patients, 7 died during the follow-up period. All but one of these patients had a normal bioprosthesis at echocardiography or at post-mortem. One patient with a plaque-covered valve had a functionally normal valve. We conclude that at present, the best available evidence suggests that although 30-day mortality approaches 20%, approximately half of patients with carcinoid syndrome undergoing tricuspid valve replacement can be expected to survive 2 years. Some patients survive considerably longer than this, beyond 10 years in some cases. Importantly, at autopsy, many replacement valves have been shown to be normal, with a few patients reported as having died of cardiac causes. This should be taken as cautious evidence that biological valves have an acceptable lifespan in patients with carcinoid syndrome and that the process of valve destruction seen in carcinoid patients does not continue to a significant level in the bioprosthesis. Caveats to this include the lack of any directly comparative trial and the predominance of case reports as opposed to higher-level evidence.

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.