Magnetic resonance imaging diagnosis of carcinoid heart disease

Artificial intelligence-augmented analysis of contemporary procedural, mortality, and cost trends in carcinoid heart disease in a large national cohort with a focus on the "forgotten pulmonic valve"

Background

Carcinoid heart disease is increasingly recognized and challenging to manage due to limited outcomes data. This is the largest known cohort study of valvular pathology, treatment (including pulmonary and tricuspid valve replacements [PVR and TVR]), dispairties, mortality, and cost in patients with malignant carcinoid tumor (MCT).

Methods

Machine learning-augmented propensity score-adjusted multivariable regression was conducted for clincal outcomes in the 2016-2018 U.S. National Inpatient Sample (NIS). Regression models were weighted by the complex survey design and adjusted for known confounders and the likelihood of undergoing valvular procedures.

Results

Among 101,521,656 hospitalizations, 55,910 (0.06%) had MCT. Patients with MCT vs. those without had significantly higher inpatient mortality (2.93 vs. 2.04%, p = 0.002), longer mean length of stay (12.20 vs. 4.62, p < 0.001), and increased mean total cost of stay ($70,252.18 vs. 51,092.01, p < 0.001). There was a step-wise increased rate of TVR and PVR with each subsequent year, with significantly more TV (0.16% vs. 0.01, p < 0.001) and PV (0.03 vs. 0.00, p = 0.040) diagnosed with vs. without MCT for 2016, with comparable trends in 2017 and 2018. There were no significant procedural disparities among patients with MCT for sex, race, income, urban density, or geographic region, except in 2017, when the highest prevalence of PV procedures were performed in the Western North at 50.00% (p = 0.034). In machine learning and propensity score augmented multivariable regression, MCT did not significantly increase the likelihood of TVR or PVR. In sub-group analysis restricted to MCT, neither TVR nor PVR significantly increased mortality, though it did increase cost (respectively, $141,082.30, p = 0.015; $355,356.40, p = 0.012).

Conclusion

This analysis reflects a favorable trend in recognizing the need for TVR and PVR in patients with MCT, with associated increased cost but not mortality. Our study also suggests that pulmonic valve pathology is increasingly recognized in MCT as reflected by the upward trend in PVRs. Further research and updated societal guidelines may need to focus on the "forgotten pulmonic valve" to improve outcomes and disparities in this understudied patient population.

Cardiac Imaging in Carcinoid Heart Disease

Carcinoid disease is caused by neuroendocrine tumors, most often located in the gut, and leads in approximately 20% of cases to specific, severe heart disease, most prominently affecting right-sided valves. If cardiac disease occurs, it determines the patient's prognosis more than local growth of the tumor. Surgical treatment of carcinoid-induced valve disease has been found to improve survival in observational studies. Cardiac imaging is crucial for both diagnosis and management of carcinoid heart disease; in the past, imaging was accomplished largely by echocardiography, but more recently, imaging for carcinoid heart disease has increasingly become multimodal and warrants awareness of the particular diagnostic challenges of this disease. This paper reviews the pathophysiology and manifestations of carcinoid heart disease in light of the different imaging modalities.

Carcinoid Heart Disease: Review of Current Knowledge

Carcinoid heart disease is the collective term for all cardiac manifestations in patients who have carcinoid syndrome. Carcinoid heart disease has a multifactorial pathophysiology, and the right side of the heart is usually involved. Symptoms and signs vary depending upon the affected cardiac components; most typical is right-sided heart failure secondary to diseased tricuspid and pulmonary valves. Despite no single ideal diagnostic test, strong suspicion, coupled with serologic and imaging results, usually enables diagnosis. Advances in imaging, such as speckle-tracking echocardiography and cardiac magnetic resonance, have improved the diagnostic yield. Treatment is challenging, warrants a multidisciplinary approach, and can be medical or surgical depending on the cardiac manifestations. Investigators are exploring the therapeutic use of monoclonal antibodies and new somatostatin analogues. In this review, we cover current knowledge about the pathophysiology, diagnosis, and treatment of carcinoid heart disease.

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.

Imaging features of carcinoid heart disease

This article reviews the basic and clinical features of heart disease associated with carcinoid syndrome, with an emphasis on its principal imaging modalities.

[Carcinoid heart - case report]

We describe the case of a 76-year-old woman, diagnosed with a neuroendocrine tumor of the cecum in 2004, with liver metastases and carcinoid syndrome since September 2010. The patient had been treated intermittently with chemotherapy cycles, and remained symptomatic, with worsening secondary lesions. In June 2011 she began to present signs and symptoms of right heart failure and was hospitalized in September 2011. Transthoracic two- and three-dimensional echocardiography revealed enlarged right atrium and ventricle and thickened and fixed tricuspid and pulmonary valve leaflets, causing severe tricuspid regurgitation and mild pulmonary regurgitation and stenosis, suggestive of carcinoid heart disease. The authors discuss the clinical importance of transthoracic echocardiography, and the more recent three-dimensional echocardiography, as the diagnostic exam of choice in these cases, as it is especially suitable for assessing the valves and subvalvular apparatus.

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.

Imaging of carcinoid tumors: spectrum of findings with pathologic and clinical correlation

Carcinoid tumors are primary malignant neoplasms that arise from neuroendocrine cells. These cells are located throughout the body, resulting in many possible locations for the development of carcinoid tumor. The most common primary location is the gastrointestinal tract, followed by respiratory and thymic carcinoids. The presentations of these tumors are variable depending on their location, aggressiveness, production of functional peptides, and tendency to invade or metastasize. Carcinoid tumors can be imaged by various modalities including gastrointestinal studies, ultrasound, computed tomography, and magnetic resonance imaging as well as nuclear medicine studies (radioactive octreotide). In this review, we illustrate the spectrum of imaging features of carcinoid tumors in various locations of the human body.

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.