Does a patient with a hematocrit level of 58, heart failure with reduced ejection fraction, pulmonary sarcoidosis, and hypertension, currently on Entresto (sacubitril/valsartan), require therapeutic phlebotomy?

Does This Patient Need Therapeutic Phlebotomy?

No, this patient with a hematocrit of 58% does not require therapeutic phlebotomy. His hematocrit is well below the threshold of 65% where phlebotomy should even be considered, and he lacks the specific clinical context (cyanotic congenital heart disease with right-to-left shunting) where secondary erythrocytosis management becomes relevant 1.

Why Phlebotomy Is Not Indicated

Hematocrit Threshold Not Met

• Therapeutic phlebotomy should only be performed when hematocrit exceeds 65% in patients with moderate to severe hyperviscosity symptoms due to secondary erythrocytosis, and only after excluding dehydration and iron deficiency 1.
• The 2019 AHA/ACC guidelines explicitly state that available data do not justify a cut point for a "safe" hematocrit, and there is no clear correlation between viscosity and a patient's symptoms or clinical condition 1.
• Routine phlebotomy is not supported by data in patients with secondary erythrocytosis 1.

Wrong Clinical Context

• The phlebotomy recommendations in the guidelines specifically address cyanotic congenital heart disease patients with right-to-left shunts (such as Eisenmenger syndrome) who develop secondary erythrocytosis as a physiological response to chronic hypoxemia 1.
• Your patient has HFrEF, pulmonary sarcoidosis, and hypertension—none of these conditions cause the type of secondary erythrocytosis that warrants phlebotomy 1.

What Should Be Done Instead

Evaluate for Reversible Causes

• First, assess hydration status—dehydration can elevate hematocrit and mimic hyperviscosity symptoms 1.
• Check iron studies (serum iron, ferritin, transferrin saturation) because mean corpuscular volume is not a reliable screening test 1.
• Rule out primary polycythemia vera if the elevated hematocrit persists without explanation, as this is a neoplastic proliferation requiring different management than secondary erythrocytosis 1, 2.

Address the Underlying Heart Failure

• Optimize guideline-directed medical therapy (GDMT) for his HFrEF, which should include all four foundational medication classes: SGLT2 inhibitor, mineralocorticoid receptor antagonist, beta-blocker, and ARNI (he is already on Entresto/sacubitril-valsartan) 3.
• Ensure adequate diuresis to achieve euvolemia, as volume overload can affect hematocrit measurements 3, 4.

Critical Pitfalls to Avoid

Never Perform Routine Phlebotomy

• Inappropriate phlebotomies to maintain a predetermined hemoglobin level cause iron deficiency, which paradoxically increases stroke risk by causing microcytosis without lowering viscosity 1.
• Iron deficiency was identified as the strongest independent predictor for cerebrovascular events in patients with secondary erythrocytosis 1.

Recognize That Hematocrit Alone Doesn't Drive Decisions

• The severity and frequency of hyperviscosity symptoms do not correlate with measured hematocrit 1.
• Even when hematocrit is elevated, rehydration with oral fluids or intravenous normal saline should be first-line therapy before considering phlebotomy 1.

Special Circumstances Where Phlebotomy Might Be Considered

• Phlebotomy (with equal volume fluid replacement) is only sometimes performed in special cases where, after adequate hydration, hematocrit remains higher than the patient's baseline AND symptoms persist, OR there is evidence of end-organ damage attributable to hyperviscosity (e.g., myocardial ischemia, transient ischemic attack/stroke) 1.
• If phlebotomy were ever indicated, it should be isovolumic with 750-1000 mL of isotonic saline while removing 400-500 mL of blood 1.