What is the best treatment approach for a patient with smoldering myeloma, pericardial effusion, and now constricted pericarditis, considering the risk of amyloidosis?

Treatment of Constrictive Pericarditis in Smoldering Myeloma

Pericardiectomy is the definitive treatment for chronic constrictive pericarditis, but in your patient with smoldering myeloma and concern for amyloidosis, you must first establish the underlying etiology through pericardial biopsy before proceeding with surgery. 1

Immediate Diagnostic Priorities

Rule out cardiac amyloidosis before any surgical intervention. In patients with plasma cell dyscrasias like smoldering myeloma, pericardial involvement can result from:

• AL amyloid deposition (most common cardiac complication of myeloma) 2, 3
• Direct plasma cell infiltration of the pericardium 2, 4
• Infectious complications (particularly in immunocompromised patients) 5

Obtain tissue diagnosis via pericardial biopsy during pericardiocentesis or pericardial window procedure to differentiate these etiologies, as this fundamentally changes management. 1, 2, 4

Diagnostic Workup Before Surgery

Perform the following to assess surgical candidacy and identify contraindications:

• Cardiac MRI with late gadolinium enhancement to detect myocardial amyloid involvement (characteristic diffuse subendocardial enhancement pattern) 3
• NT-proBNP levels (markedly elevated in cardiac amyloidosis, often >4,000 pg/mL) 3
• Echocardiography looking for restrictive physiology, "sparkling" myocardium, and ventricular wall thickness 3
• Cardiac catheterization to confirm constrictive physiology and rule out restrictive cardiomyopathy 1, 5
• Serum and urine immunofixation with free light chains to assess myeloma activity 4

Treatment Algorithm Based on Etiology

If Chronic Constrictive Pericarditis WITHOUT Amyloidosis:

Proceed with complete pericardiectomy for NYHA Class III-IV symptoms (Class I recommendation). 1

• Surgery must remove both parietal AND visceral pericardial layers as completely as technically feasible 1
• Use median sternotomy approach (not left thoracotomy) to allow complete resection including right atrium, both venae cavae, and inferior right ventricle 1
• Refer to experienced surgical centers given operative mortality of 6-12% 1

Critical Surgical Contraindications:

Do NOT proceed with pericardiectomy if:

• Cardiac amyloidosis is present - pericardiectomy will not address underlying restrictive myocardial disease and carries prohibitive risk 6, 3
• End-stage disease markers: cachexia, cardiac index <1.2 L/m²/min, hypoalbuminemia, hepatic dysfunction (Child-Pugh score ≥7) 1
• Significant renal dysfunction or ESRD (independent predictor of pericardiectomy mortality) 1

If Transient/Inflammatory Constriction:

Trial of conservative medical therapy for 2-3 months before surgery in hemodynamically stable patients without chronic disease markers (cachexia, atrial fibrillation, calcification). 1

• Colchicine 0.5 mg once or twice daily (depending on weight <70 kg) 1, 5
• NSAIDs as adjunctive anti-inflammatory therapy 1
• Monitor CRP levels to guide treatment duration and response 1

This approach is supported by case reports showing resolution of post-surgical constrictive pericarditis with colchicine therapy. 5

If Effusive-Constrictive Pericarditis:

Pericardiocentesis with hemodynamic monitoring to diagnose (persistently elevated right atrial pressure >10 mmHg post-drainage despite adequate fluid removal). 1

• If confirmed, visceral pericardiectomy is required (not just parietal) - technically demanding procedure requiring experienced surgeons 1
• Consider pericardial window only if patient is too high-risk for complete pericardiectomy 7

Special Considerations for Myeloma-Related Disease

If Plasma Cell Infiltration Confirmed:

Systemic chemotherapy is the primary treatment, not surgery. 2, 4

• Pericardial involvement by myeloma cells typically occurs in advanced disease and carries poor prognosis 2, 4
• Pericardial window for palliation if recurrent tamponade despite chemotherapy 7, 2
• Consider intrapericardial chemotherapy (bleomycin has been reported) for malignant effusions, though evidence is limited 6

If Cardiac Amyloidosis Present:

Focus on treating the underlying plasma cell dyscrasia, not the pericardium. 3

• Proteasome inhibitor-based chemotherapy (e.g., bortezomib, cyclophosphamide, dexamethasone) targets light chain production 3
• Cardioprotective therapy: ACE inhibitors/ARBs, beta-blockers (use cautiously in restrictive physiology), statins 3
• Avoid pericardiectomy - will not improve outcomes and carries excessive risk 6, 3
• Prognosis is determined by cardiac involvement severity, not pericardial disease 3

Key Pitfalls to Avoid

• Never assume "idiopathic" constrictive pericarditis in a patient with known plasma cell dyscrasia - always obtain tissue diagnosis 2, 4
• Do not perform pericardiectomy without ruling out myocardial amyloidosis - surgery will fail and harm the patient 6, 3
• Avoid incomplete pericardiectomy via left thoracotomy - leads to recurrence and need for reoperation 1
• Do not rush to surgery in newly diagnosed constriction - some cases are transient and resolve with anti-inflammatory therapy 1, 5