Cardiac Papillary Fibroelastoma

Benign avascular tumour of the endocardium, the commonest valve tumour and the second commonest benign primary cardiac tumour (about 7 to 10% of primary cardiac tumours, and about three quarters of valve tumours). It is composed of branching, frond like fibroelastic projections covered by endothelium on a short stalk, resembling a sea anemone when suspended in fluid.

• Usual size is 5 to 15 mm (up to 70 mm described). Sites: aortic valve about 30 to 40% (aortic surface), mitral valve about 25 to 35% (atrial surface), tricuspid and pulmonary valves, and non-valvular endocardium in 10 to 20%.
• Mean age is 60 to 70 years, with equal sex distribution. The cause is unclear: it may be a reactive lesion after endocardial injury (cardiac surgery, radiation, valve procedures, hypertrophic cardiomyopathy) or a hamartoma.
• The danger is embolism of fragments or surface thrombus: stroke or transient ischaemic attack in about 15 to 25% of symptomatic patients, coronary embolism or ostial obstruction causing myocardial infarction, retinal artery occlusion, and pulmonary embolism with right sided lesions. Obstruction and valve dysfunction are rare.

• Most patients are asymptomatic, and the tumour is found incidentally on echocardiography or at surgery or autopsy.
• Presentations: transient ischaemic attack or stroke with no other cause, myocardial infarction or angina, retinal artery occlusion, syncope, dyspnoea (large lesions), and pulmonary embolism. Murmurs are uncommon.
• Differential diagnosis: Lambl excrescences (thin filiform strands 1 to 2 mm on the line of valve closure, more frequent in the elderly), infective endocarditis vegetation (fever, positive blood cultures, valve destruction), marantic (nonbacterial thrombotic) vegetations in cancer or lupus, thrombus, myxoma, fibroma, calcified valve nodule, ruptured chordae, and ruptured cusp fenestration.
• Complications: cerebral and retinal ischaemia, myocardial infarction, recurrent embolism, rarely sudden death, and rarely valve obstruction.

• Transthoracic echocardiography detects larger lesions; transoesophageal echocardiography is the most sensitive test and shows a small, round or oval, mobile mass with a stalk and a shimmering, speckled edge.
• Cardiac MRI and CT help little for lesions under 10 mm but can exclude other tumours and thrombus.
• Embolic workup: brain imaging, carotid and vertebral imaging, and prolonged ECG monitoring (14 to 30 days) for atrial fibrillation, because atrial fibrillation is a commoner cause of cardioembolic stroke.
• Blood cultures, CRP, ESR and full blood count to exclude infective endocarditis. Coronary CT angiography or invasive angiography before surgery in older patients.
• Histology after excision is confirmatory.

• Decide by symptoms, site and mobility.
• Surgical excision:
  • Symptomatic patients (any embolic event with no other cause): excision, ideally within days to weeks.
  • Asymptomatic left sided lesions that are mobile or larger than 1 cm: consider excision when the operative risk is low (especially in younger patients).
  • Technique: shave excision with preservation of the native valve, performed under cardiopulmonary bypass; valve repair is possible in over 90% and valve replacement is rare.
  • Operative mortality is less than 1 to 3%; recurrence is very rare.
  • Perioperative antibiotic: cefazolin 2 g IV at induction.
• Observation:
  • Small (less than 1 cm), non-mobile, right sided or asymptomatic lesions: echocardiography every 6 to 12 months for 2 years, then yearly if stable, with immediate review for any neurological or visual symptom.
• Antithrombotic therapy for patients who are not surgical candidates or are waiting for surgery:
  • Aspirin 75 to 100 mg daily, or warfarin to INR 2.0 to 3.0 after an embolic event. Evidence that antithrombotic therapy prevents embolism from the tumour is limited.
• Acute ischaemic stroke:
  • Alteplase 0.9 mg/kg (maximum 90 mg), 10% as a bolus and the rest over 60 minutes, within 4.5 hours of onset has been used safely in case reports because the tumour is avascular, and mechanical thrombectomy is used for large vessel occlusion. Evidence is limited.
• Do not manipulate a left sided lesion with catheters.
• Special groups:
  • Pregnancy: observe if asymptomatic; excise with bypass after an embolic event, ideally in the second trimester.
  • Children: very rare; excise when symptomatic.
  • Elderly with high operative risk: antiplatelet or anticoagulant therapy with surveillance.
• Red flags: transient ischaemic attack, stroke, sudden visual loss, chest pain with ST change, a lesion that grows or becomes more mobile.
• Follow up: echocardiography at 1 and 12 months after surgery, then if symptoms arise; yearly echocardiography for observed lesions.