In a 53‑year‑old man with combined systolic‑diastolic heart failure, persistent erythrocytosis (hemoglobin 18.3 g/dL, hematocrit 54 %, RBC 5.97 ×10^12/L), history of pulmonary sarcoidosis in remission, normal cardiac imaging and electrophysiology, and a benign 0.62‑mm gallbladder polyp, how should I proceed with management given that the hematologist declined to treat the erythrocytosis?

Proceed with Therapeutic Phlebotomy to Target Hematocrit <54% and Investigate Secondary Causes of Erythrocytosis

In this patient with heart failure and persistent erythrocytosis (Hct 54%, Hgb 18.3 g/dL), you should initiate therapeutic phlebotomy to reduce hematocrit below 54% while simultaneously investigating secondary causes of erythrocytosis, particularly hypoxia-driven mechanisms related to his cardiac disease.

Immediate Management: Therapeutic Phlebotomy

The hematologist's refusal to treat is problematic because elevated hematocrit directly worsens outcomes in heart failure through increased blood viscosity and impaired tissue oxygen delivery. Clinical evidence shows:

• In heart failure specifically, elevated hematocrit increases blood viscosity and flow resistance, paradoxically worsening tissue oxygenation despite higher oxygen-carrying capacity 1
• Target hematocrit should be in the physiological range (39-50% for men), not the current 54% 1
• Judicious phlebotomy to hematocrit ~50-52% is reasonable and may alleviate hyperviscosity symptoms while providing hemodynamic improvement 2

Begin phlebotomy of 250-500 mL every 1-2 weeks until hematocrit reaches 50-52%, monitoring symptoms of dyspnea and chest discomfort for improvement.

Diagnostic Work-Up for Secondary Erythrocytosis

The elevated ferritin (576) argues against polycythemia vera, which typically causes iron deficiency from increased utilization. This pattern suggests secondary erythrocytosis. Prioritize these investigations:

1. Hypoxia Assessment (Most Likely)

• Arterial blood gas with co-oximetry to measure:
  • Arterial oxygen saturation (not pulse oximetry—need actual PaO2)
  • Carboxyhemoglobin level (especially if any smoking history)
• Overnight oximetry or sleep study: Heart failure patients commonly have central sleep apnea or obstructive sleep apnea causing nocturnal hypoxemia, which drives erythropoietin production 3
• His dyspnea and "chest slamming sensations" could reflect sleep-disordered breathing

2. Serum Erythropoietin Level

• Low or normal EPO → suggests polycythemia vera (though ferritin argues against this)
• Elevated EPO → confirms secondary erythrocytosis and directs investigation toward hypoxic causes 2

3. JAK2 Mutation Testing

Despite the hematologist's assessment, order JAK2 V617F mutation to definitively exclude polycythemia vera. The TRAKJAK score can guide pre-test probability, but given persistent erythrocytosis over one year, testing is warranted 4

4. Cardiac-Specific Considerations

• Right heart catheterization data (if available from prior workup): Elevated pulmonary pressures or right-to-left shunting can cause hypoxemia
• His sarcoidosis history raises concern for pulmonary hypertension (Group 5 PH from sarcoidosis or Group 2 from heart failure), which can cause hypoxic erythrocytosis 5
• Review cardiac MRI for any structural abnormalities causing shunting

Why the Gallbladder Recommendation Is Irrelevant

The 0.62 mm benign gallbladder polyp is a red herring. Polyps <10 mm without concerning features do not require cholecystectomy and have no relationship to erythrocytosis. Disregard this recommendation.

Heart Failure Optimization

While addressing erythrocytosis, ensure guideline-directed medical therapy (GDMT) for heart failure is maximized 3:

• Beta-blockers, ACE inhibitors/ARBs/ARNI, mineralocorticoid receptor antagonists
• SGLT2 inhibitors (dapagliflozin or empagliflozin): Interestingly, these medications transiently increase hemoglobin by 0.5-1.0 g/dL through hemoconcentration, but this effect is not associated with adverse outcomes and actually correlates with improved NT-proBNP reduction 6
• If using SGLT2 inhibitors, the modest hemoglobin rise is expected and benign—do not attribute the entire erythrocytosis to this

Common Pitfalls to Avoid

1. Do not accept "no treatment" for Hct 54% in heart failure: Hyperviscosity directly impairs cardiac function
2. Do not assume polycythemia vera without JAK2 testing: Elevated ferritin makes this unlikely
3. Do not ignore sleep-disordered breathing: This is the most common missed cause of secondary erythrocytosis in heart failure patients 3
4. Do not over-phlebotomize: Target Hct 50-52%, not normal range, to avoid inducing anemia which independently worsens heart failure outcomes 3, 6

Monitoring Strategy

• Hematocrit every 2-4 weeks during phlebotomy phase
• Ferritin and iron studies after achieving target Hct (phlebotomy will deplete iron stores)
• Symptom assessment: Dyspnea, exercise tolerance, chest discomfort should improve with Hct reduction
• NT-proBNP trends: May improve with better rheology 6

If secondary causes are identified (sleep apnea, nocturnal hypoxemia), treat the underlying condition with CPAP or oxygen therapy, which may reduce erythropoietin drive and stabilize hematocrit long-term 3, 2.