Cardiac Case Study: February 2008

Cardiac Case Study: February 2008

Right Heart Failure in Carcinoid Syndrome

By Michael McDaniel, MD, Cardiology Fellow, Emory University School of Medicine

A 49-year-old man with a history carcinoid syndrome recently presented with 8 weeks of progressive dyspnea, leg swelling, 50-pound weight gain and fatigue.

He had been diagnosed with carcinoid syndrome 10 years earlier when he was admitted to the local Veterans Administration hospital for alcohol detoxification. At that time, he also had complained of abdominal pain and diarrhea, and a computed tomography (CT) scan was ordered for presumed chronic pancreatitis. The CT scan revealed hypervascular hepatic lesions and a 4 cm by 5 cm small-bowel mass. A liver biopsy was performed, and results were consistent with a neuroendocrine
carcinoma. His 24-hour urine 5-hydroxyindolacetic acid (5-HIAA) levels were elevated at 253 mg/day (normal is <2-8 mg/day). The biopsy results and elevated 5-HIAA levels confirmed a diagnosis of carcinoid syndrome. He was started on octreotide to reduce his serotonin levels, and this controlled his diarrhea.

Severe tricuspid stenosis

On physical examination, his heart rate was 125/minute with an irregular rhythm. There was a III/VI holosystolic murmur in the lower-left sternal border that increased with respiration and a II/VI systolic ejection murmur at the upper-left sternal border. There was severe volume overload (50+ pounds), pitting edema (3+ in his lower extremities and 2+ in his upper extremities), severe hepatomegaly and tense ascites. Breath sounds were decreased, and the jugular venous pressures were elevated at 90 degrees.

A chest X-ray demonstrated bilateral pleural effusions and right atrial enlargement. The CT scan of the liver demonstrated multiple metastatic lesions and marked ascites. An electrocardiogram was consistent with atrial fibrillation with a rapid ventricular response. Echocardiography also demonstrated severe tricuspid stenosis and regurgitation (Figures 1 and 2), as well as pulmonary valve stenosis (Figure 3).

Apical view showing tricuspid regurgitation

Right heart catheterization was performed with simultaneous catheters in the right atria and right ventricle. Simultaneous right atrial and right ventricular pressure tracing revealed a mean gradient of 8 mm Hg across the tricuspid valve. There were large “v” waves noted in the right atrial tracing, and mean right atrial pressure was 22 mm Hg.

Abnormal laboratory values included a low hematocrit (33.5%), a serum BNP of 4,737 pg/mL and 24-hour urine 5-HIAA of 130 mg.

The patient was diagnosed with carcinoid heart disease. He had severe tricuspid regurgitation, severe tricuspid stenosis and severe pulmonic regurgitation. In addition, there was moderate to severe right ventricular dysfunction.

Pulmonary valve stenosis

The patient underwent intravenous diuresis and paracentesis and lost more than 80 lbs of fluid. With diuresis and amiodarone, he reverted to normal sinus rhythm. He was seen by cardiothoracic surgeons and offered a tricuspid and pulmonic valve replacement, but refused the procedure. He was also offered palliative tricuspid valve valvuloplasty and refused. He was discharged home to follow up as an outpatient. Patient is stable and is continuing follow-up care.

Carcinoid tumors are rare, occurring at a rate of only 2.5 per 100,000 among Caucasians and 4.2 per 100,000 among African-Americans. Carcinoid tumors develop from neuroendocrine cells in the gastrointestinal tract (where 90% originate), with the most common sites being the appendix and terminal ileum.

Often, these tumors are benign and only locally invasive, but metastatic tumors can become endocrinologically active and secrete a variety of polypeptides and hormones. Between 20% and 30% of these patients develop carcinoid syndrome, a constellation of symptoms related to the release of these vasoactive substances. The most common factor released is serotonin, which is measured in the urine by its metabolite 5-HIAA.

The symptoms include flushing, secretory diarrhea, wheezing, telangiectasias, paroxysmal hypotension (carcinoid crisis) and valvular heart disease. In most cases, carcinoid syndrome is associated with the presence of hepatic metastases. Metastatic tumor growth within the liver allows for large quantities of humoral tumor products to reach the circulation without being inactivated by first-pass metabolism in the liver. Rarely, patients with primary pulmonary or ovarian carcinoid tumors develop carcinoid syndrome because the drainage of the vasoactive substances bypasses the portal circulation.

Carcinoid heart disease is seen in 60% of patients with metastatic carcinoid. The severity of the heart disease correlates with 5-HIAA levels. Left-sided carcinoid heart disease is seen very rarely – only in about 7% of cases – and almost always in the setting of shunts or primary pulmonary sources. The tricuspid valve is involved in 97% of patients with carcinoid heart disease, and the pulmonic valve is involved in 88%. In 4% of cases, intracardiac metastases are noted, and 14% have small pericardial effusions. The 3-year survival rate is 31% with cardiac involvement. Reducing 5-HIAA levels with medications does not cause regression of cardiac lesions.

The subject of this study is a patient with carcinoid heart disease. He had a primary mid-gut tumor that was metastatic to the liver. He had significant involvement of the tricuspid valve, which caused severe tricuspid regurgitation and severe tricuspid stenosis. There was also significant involvement of the pulmonic valve, causing both pulmonicstenosis and severe pulmonic regurgitation.

Due to carcinoid deposits in the right ventricle and severe right-sided valvular heart disease, this patient suffered from significant right heart failure. The acute onset of atrial fibrillation may have precipitated his recent decline in functional status due to the loss of the “diastolic kick” and decreased diastolic filling period associated with tachycardia. While the symptoms and prognosis in carcinoid heart disease may improve with early surgery, patients with advanced cardiac lesions often have a poor long-term survival with or without surgery.

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