Should I hold enoxaparin (Lovenox) in a patient with a platelet count of 59 ×10⁹/L that is decreasing after a recent cerebrovascular accident?

Management of Enoxaparin in Acute CVA with Platelet Count 59 × 10⁹/L and Declining

Hold enoxaparin immediately and do not restart until platelet count is stable above 50 × 10⁹/L, with careful consideration of whether this represents an ischemic versus hemorrhagic stroke.

Critical Decision Point: Type of Stroke

Your clinical scenario states "sure CVA" but does not specify whether this is an ischemic stroke or hemorrhagic stroke (intracranial hemorrhage). This distinction is absolutely critical:

If This Is Intracranial Hemorrhage (Hemorrhagic Stroke):

Discontinue enoxaparin immediately and consider reversal with protamine. 1

• The Neurocritical Care Society strongly recommends discontinuing LMWH when intracranial hemorrhage is present or suspected (Good Practice statement). 1
• They strongly recommend reversing LMWH in patients with intracranial hemorrhage receiving therapeutic doses (Strong recommendation, moderate evidence). 1
• Protamine should be administered by slow IV injection over 10 minutes: If enoxaparin was given within 8 hours, give 1 mg protamine per 1 mg enoxaparin (maximum 50 mg single dose); if given 8-12 hours ago, give 0.5 mg protamine per 1 mg enoxaparin. 1
• Do not restart anticoagulation in the setting of active intracranial hemorrhage. 1

If This Is Ischemic Stroke:

The decision is more nuanced and depends on thrombocytopenia severity and trend:

Thrombocytopenia Management Algorithm

Platelet Count 50-59 × 10⁹/L (Your Current Situation):

Hold enoxaparin temporarily. 1

• The International Society on Thrombosis and Haemostasis (ISTH) guidance on cancer-associated thrombosis (applicable principles here) states: "We recommend giving full therapeutic anticoagulation without platelet transfusion to patients with CAT and a platelet count of ≥ 50 × 10⁹/L." 1
• Your patient at 59 × 10⁹/L is just below this threshold, but the declining trend is the critical concern—you cannot predict where the nadir will be. 1
• For acute thrombosis with platelet count <50 × 10⁹/L and lower risk of thrombus progression, ISTH suggests reducing LMWH to 50% therapeutic dose or prophylactic dose for platelet counts 25-50 × 10⁹/L. 1

Platelet Count 25-50 × 10⁹/L:

Use reduced-dose enoxaparin (50% of therapeutic dose or prophylactic dose) only if thrombotic risk is high. 1

• ISTH suggests reducing the dose of LMWH to 50% of the therapeutic dose or using a prophylactic dose in this range. 1
• The American Society of Clinical Oncology states that most experts agree therapeutic anticoagulation with LMWH may be administered if platelet count can be maintained above 50 × 10⁹/L. 1
• For platelet counts between 20 and 50 × 10⁹/L, half-dose LMWH can be administered with close follow-up for bleeding. 1

Platelet Count <25 × 10⁹/L:

Temporarily discontinue all anticoagulation. 1

• ISTH recommends temporarily discontinuing anticoagulation while platelet count is <25 × 10⁹/L. 1
• ASCO states that if platelet count is <20 × 10⁹/L, therapeutic doses of anticoagulation should be held. 1

When to Resume Full-Dose Enoxaparin

Resume full-dose LMWH when platelet count is >50 × 10⁹/L without transfusion support and is stable or rising. 1

• ISTH recommends resuming full-dose LMWH when platelet count is >50 × 10⁹/L without transfusion support, in the absence of other contraindications. 1
• The platelet count must be stable or trending upward, not just transiently above 50 × 10⁹/L. 1

Platelet Transfusion Considerations

Do not routinely transfuse platelets to enable anticoagulation unless the patient requires urgent neurosurgical intervention. 1

• For acute thrombosis with severe thrombocytopenia and higher risk of thrombus progression, ISTH suggests full-dose anticoagulation with platelet transfusion support to maintain platelet count ≥40-50 × 10⁹/L. 1
• The Neurocritical Care Society suggests against platelet transfusion for antiplatelet-associated intracranial hemorrhage in patients who will NOT undergo neurosurgical procedure. 1
• They suggest platelet transfusion for patients with aspirin- or ADP inhibitor-associated intracranial hemorrhage who WILL undergo neurosurgical procedure (Conditional recommendation, moderate evidence). 1

Critical Pitfalls to Avoid

Do Not Continue Standard-Dose Enoxaparin with Declining Platelets:

The declining trend is more concerning than the absolute number. 1

• You risk precipitating severe thrombocytopenia (<25 × 10⁹/L) where all anticoagulation must stop. 1
• This could represent heparin-induced thrombocytopenia (HIT), which has catastrophic thrombotic consequences if enoxaparin is continued. 2, 3, 4

Evaluate for Heparin-Induced Thrombocytopenia (HIT):

Check baseline platelet count and calculate the percentage drop. 2, 3, 4

• HIT typically causes a >50% drop in platelet count from baseline, usually occurring 5-10 days after heparin exposure. 2, 3, 4
• If HIT is suspected, immediately discontinue all heparin products (including enoxaparin) and switch to a non-heparin anticoagulant such as fondaparinux, argatroban, or bivalirudin. 5
• Do NOT use enoxaparin in confirmed HIT—88% of strongly positive HIT plasma samples cross-react with enoxaparin. 3

Do Not Restart Enoxaparin Within 24 Hours of IV Alteplase:

If this ischemic stroke was treated with thrombolysis, delay enoxaparin for at least 24 hours after IV alteplase and only after follow-up CT/MRI confirms no hemorrhagic transformation. 5

• The American Heart Association states that anticoagulation within the first 24 hours after alteplase is uncertain (Class IIb, Level B-NR) and should only be considered when withholding treatment poses substantial risk. 5

Practical Clinical Algorithm

1. Immediately hold enoxaparin given platelet count 59 × 10⁹/L and declining. 1
2. Confirm stroke type with imaging (CT or MRI) to rule out intracranial hemorrhage. 1, 5
3. Evaluate for HIT: Check baseline platelet count, calculate percentage drop, and send HIT antibody panel if >50% drop or 5-10 days post-heparin exposure. 2, 3, 4
4. Monitor platelet count daily until trend is established. 1
5. If platelet count stabilizes >50 × 10⁹/L and stroke is ischemic: Resume full-dose enoxaparin. 1
6. If platelet count remains 25-50 × 10⁹/L: Use reduced-dose enoxaparin (50% therapeutic or prophylactic dose) only if thrombotic risk outweighs bleeding risk. 1
7. If platelet count falls <25 × 10⁹/L: Discontinue all anticoagulation. 1
8. If HIT is confirmed: Switch to fondaparinux, argatroban, or bivalirudin—never restart enoxaparin. 5, 3