A 42-year-old female applied for life insurance. Nine years prior to the application she was diagnosed with a fibroelastoma of the aortic valve by transesophageal echocardiogram. Detailed records from that time were not included.
Within the year prior to application she complained of palpitations and had a 24-hour ambulatory heart monitor. This revealed 2027 isolated Ventricular Ectopic Beats, 1317 episodes of bigeminy and five runs of ventricular tachycardia lasting 3-6 beats. She was started on Metoprolol.
She also had an exercise test during which she exercised to 12 minutes. It showed decreasing ectopy with exercise, and the tracing was negative for ST changes. A repeat transthoracic echo again showed the presumed ~ 6mm fibroelastoma of the aortic valve and an ejection fraction of 51%.
What is a fibroelastoma, and what are the prognostic implications?
Primary cardiac tumors are very rare, with an estimated incidence of less than 0.1 percent in the population. Much more common (20 times) are metastatic cancers to the heart from primaries occurring elsewhere in the body.
When tumors do arise primarily in the heart, they are benign more than 75% of the time. Primary malignant tumors of the heart are exceptionally rare and beyond the scope of this case review.
The most common benign heart tumor in adults is a myxoma. Myxomas typically arise in the left atrium (80%) with fewer (20%) arising in the right atrium. The second most common type of cardiac tumor in adults is the fibroelastoma (Figure 1), also known as cardiac papillary fibroelastoma (CPF).
|Figure 1 - Cardiac Papillary Fibroelastoma|
While heart tumors are rare overall, fibroelastoma ranks as the second most common primary cardiac growth. Cardiac papillary fibroelastoma typically has multiple fronds attached by a small pedicle. Some have described them as looking like a sea anemone.
A review article encompassing 725 cases of CPF revealed that 55% of cases occurred in males. Most cases were discovered between the ages of 70-79, although that may be related to increased use of cardiac imaging, as the mean age was 60 years. The age range was newborn to age 92.
The average size of the tumors was 9mm with a range of 2mm to 70mm. The location of the CPF tumors in the series are listed in Figure 2, along with the percentages found at each location.
|Figures represent 611 cases reviewed. The total is > 100% because 6.2% had tumors in multiple sites (one patient had eight tumors at various locations).|
Causes & Complications
The cause of CPF is not known, and no familial predisposition has been reported.
30%–50% or more of CPF tumors are asymptomatic and discovered incidentally via a transthoracic echocardiogram (TTE), magnetic resonance imaging (MRI), computed tomography (CT) or at autopsy.
Symptoms, when present, are related to complications of the tumor. Embolic complications in the form of cerebrovascular accident or transient ischemic attack are the most common symptomatic presentation, although emboli to peripheral arteries and coronary arteries have also been described.
Tumors on the right side of the heart may cause pulmonary emboli. Large mobile tumors can obstruct blood flow across a valve or coronary artery ostia. These complications may result in symptoms like angina, myocardial infarction or sudden death.
Chronic obstruction may cause heart failure. Syncope or presyncope are not uncommon as symptoms associated with large tumors.
Diagnosis & Treatment
The diagnosis of CPF is initially suspected from seeing a small valvular or endocardial mass which may be mobile or sessile. The mass often appears to be speckled with echolucencies near the edges caused by the “fronds” or papillary projections on the surface of the tumor. Transesophageal echocardiography (TEE) is often required to confirm the diagnosis and best characterize the tumor.
In one study of CPF > 2mm in size, the sensitivity and specificity of TTE was 88.9% and 87.8% respectively. CT or MRI can also be used to additionally define the tumor or to image coronary arteries for signs of ischemia or embolization (magnetic resonance or computed tomographic angiography). Cardiac catheterization is usually not required and carries a risk of dislodging tumor fragments or thrombi resulting in damaging emboli.
Treatment of CPF is surgical excision. Prognosis is excellent after successful excision, with several sources reporting no known recurrences. Some authors have suggested that some tumors can be monitored, with or without antiplatelet treatment.
Proposed indications for surgery include a tumor that is mobile or >1cm in size, a young patient, low surgical risk, associated cardiac conditions that require surgery, a history of embolic complications and/or the presence of symptoms. At least one study has identified tumor location on the aortic valve as having an adjusted odds ratio of ~ 4.1 for future risk of tumor embolism.
Since surgical excision is common with CPF, we were unable to find much data on untreated tumors. One small series of 45 patients with presumed CPF by TTE followed for 552+706 days showed three embolic events (2 TIA, 1 CVA) for an incidence of 6.6%.
Another study followed a small group of 25 patients who did not have surgery but had reported adverse outcomes. Twelve had CPF-related death due to valve obstruction or coronary artery embolization. Four others had non-fatal embolization (2 coronary, 1 cerebral, 1 pulmonary).
Returning to the Case
While some case series mentioned atrial fibrillation in association with CPF, especially when arising from the mitral valve, none mentioned ventricular ectopy as a prominent feature. Sudden cardiac death did occur, and CPF was later identified on autopsy.
One mechanism of sudden death was thought due to the tumor seeding emboli to the coronary arteries. These emboli may be due to thrombus forming on the surface of the tumor or tumor material detaching.
Given the recent symptoms and findings in this case, it appears prudent to postpone coverage until definitive treatment has stabilized the clinical situation.
Gowda RM, et al. “Cardiac papillary fibroelastoma: A comprehensive analysis of 725 cases.” Am Heart J 2003; 146:404–10.
ElBardissi AW, et al. “Embolic Potential of Cardiac Tumors and Outcome After Resection A Case–Control Study.” Stroke 2009; 40:156-162.
Sun J, et al. “Clinical and Echocardiographic Characteristics of Papillary Fibroelastomas; A Retrospective and Prospective Study in 162 Patients.” Circulation 2001; 103:2687-2693.
Greenwood JP, et al. “Cardiac tumours.” Advanced Cardiac Imaging 2015. Elsevier pp585-615.
Val-Bernal JF, et al. “Cardiac papillary fibroelastoma: Retrospective clinicopathologic study of 17 tumors with resection at a single institution and literature review.” Pathology – Research and Practice 2013 209 (2013); 208– 214.
Up to Date – Cardiac tumors, last accessed 12/1/2015.