Carcinoid and the Heart

KEY FEATURES

ESSENTIALS OF DIAGNOSIS

• CT or other imaging of neuroendocrine tumor(s) in the gut, with possible liver or pulmonary metastases

• Elevated 5-hydroxyindoleacetic acid (5-HIAA) in the urine or plasma

• Cardiac examination evidence of tricuspid regurgitation or pulmonic stenosis

• Echocardiographic evidence of thickened tricuspid or pulmonary valves

GENERAL CONSIDERATIONS

• Carcinoid tumors are neuroendocrine in origin and often secrete serotonin or other vasoactive amines

• About 15% of carcinoid patients develop symptoms of flushing and diarrhea due to hepatic metastases (carcinoid syndrome)

• About 50% of carcinoid syndrome patients develop valvular heart disease, mainly of the right heart valves

• The endothelial lesion consists of distinctive fibrotic plaques that adhere to the valves and chamber walls

• Valvular plaques usually result in tricuspid regurgitation and pulmonic stenosis

• Bronchial tumors can result in left heart valve disease

CLINICAL PRESENTATION

SYMPTOMS AND SIGNS

• Symptoms range from flushing to diarrhea to profound hypotension

• Symptoms of right heart failure may be present: ascites and edema

PHYSICAL EXAM FINDINGS

• Jugular venous elevation with a large v wave may be present

• The murmur of tricuspid regurgitation or pulmonic stenosis may be present

• Signs of right heart failure may be present: ascites, edema

DIFFERENTIAL DIAGNOSIS

• Other causes of pulmonic stenosis, tricuspid regurgitation, and right heart failure

• Consumption of serotonin-rich foods can give false-positive 5-HIAA screening test results

DIAGNOSTIC EVALUATION

LABORATORY TESTS

• Twenty-four-hour urine or plasma for elevated 5-HIAA levels

• High N-terminal pro-B-type natriuretic peptide levels are of diagnostic and prognostic value

ELECTROCARDIOGRAPHY

• Some patients demonstrate right ventricular hypertrophy or right atrial enlargement

IMAGING STUDIES

• Abdominal CT is indicated to locate the primary tumor and hepatic or other metastases

• Echocardiography shows the characteristic diffuse thickening of the right heart valves with an echogenic material

  • – Doppler echo shows tricuspid regurgitation and pulmonic stenosis

• Right ventricular volume and systolic function are important for prognosis

• Cardiac CT is useful adjunct for diagnosing cardiac sarcoid and assessing coronary disease

• Cardiac MRI is also useful, especially in patients with poor echo windows

• Late gadolinium enhancement of the endocardium and valves is characteristic

DIAGNOSTIC PROCEDURES

• Cardiac catheterization may be required in selected patients

TREATMENT

CARDIOLOGY REFERRAL

• Evidence of significant valvular disease

• Right heart failure

• Endocarditis

HOSPITALIZATION CRITERIA

• Right heart failure

• Endocarditis

• Profound hypotension

MEDICATIONS

• Somatostatin analog therapy to control symptoms:

  • – Octreotide 50–150 μg 2–4 times a day SC or IV; maximum ...