What is the management approach for a patient with dengue (Dengue Fever) who has undergone Percutaneous Transluminal Coronary Angioplasty (PTCA) and is on Dual Antiplatelet Therapy (DAPT)?

Management of Dengue in Post-PTCA Patient on DAPT

Immediate Risk Assessment and Decision Framework

In a post-PTCA patient on DAPT who develops dengue, continue DAPT unless active severe bleeding occurs, as the thrombotic risk from stent thrombosis outweighs the bleeding risk in most dengue cases, and temporary discontinuation should only be considered with individualized assessment of timing from PCI, platelet count, and bleeding severity. 1

Critical Timing Considerations

Time from PTCA is the most crucial factor in decision-making:

• If within 30 days of PCI: Stent thrombosis risk is highest (up to 2%), and DAPT should be maintained unless life-threatening bleeding occurs 1
• If 1-6 months post-PCI: Consider temporary discontinuation of one antiplatelet agent only if platelet count drops below 20,000/μL with active bleeding 1
• If beyond 6 months post-PCI: More flexibility exists to temporarily reduce to single antiplatelet therapy during critical dengue phase 1

Platelet Count-Based Management Algorithm

Platelet count >50,000/μL:

• Continue full DAPT (aspirin + P2Y12 inhibitor) 2
• Monitor daily platelet counts and clinical bleeding 3, 4
• No prophylactic platelet transfusion indicated 3

Platelet count 20,000-50,000/μL:

• If <30 days post-PCI: Continue DAPT with intensive monitoring 1
• If >30 days post-PCI: Consider discontinuing aspirin while maintaining P2Y12 inhibitor 1
• Avoid prophylactic platelet transfusion (not superior to supportive care and increases adverse events) 3

Platelet count <20,000/μL without bleeding:

• If <30 days post-PCI: Continue DAPT with multidisciplinary consultation involving cardiology and hematology 1
• If >30 days post-PCI: Temporarily discontinue aspirin, maintain P2Y12 inhibitor 1, 2
• Do not give prophylactic platelet transfusion 3

Active Bleeding Management

Mild bleeding (petechiae, gum bleeding, epistaxis):

• Continue DAPT if >30 days post-PCI 1, 2
• Consider discontinuing aspirin only if <30 days post-PCI 1
• Local hemostatic measures (nasal packing, etc.) 1

Severe bleeding (GI bleeding, intracranial hemorrhage, hemodynamic instability):

• Immediately discontinue both antiplatelet agents regardless of timing from PCI 1
• Platelet transfusion indicated for therapeutic purposes (not prophylactic) 3
• Restart antiplatelet therapy as soon as hemostasis achieved, beginning with single agent 1, 5
• The mortality risk from uncontrolled severe bleeding exceeds stent thrombosis risk 5

Monitoring Parameters During Dengue Critical Phase (Days 4-6)

Daily laboratory monitoring should include:

• Platelet count (predictor of mortality if <50,000/μL) 6, 4
• Hematocrit (rising hematocrit indicates plasma leakage) 4
• AST/ALT (>400 U/L predicts severe dengue) 4
• Albumin (<35 g/L predicts severe dengue) 4
• PT/PTT (prolonged PTT >30 seconds predicts bleeding) 6

Specific Antiplatelet Agent Considerations

P2Y12 inhibitor selection matters:

• If on ticagrelor or prasugrel with bleeding concerns, consider switching to clopidogrel (lower bleeding risk) 1, 7
• Clopidogrel is preferred when balancing thrombotic and bleeding risks 1, 7
• Loading dose of clopidogrel 600 mg if switching from ticagrelor 1

Critical Pitfalls to Avoid

• Never discontinue both antiplatelet agents simultaneously unless life-threatening bleeding - this dramatically increases stent thrombosis risk, which carries 20-40% mortality 1
• Do not give prophylactic platelet transfusions - they do not prevent bleeding and increase adverse events including anaphylaxis, transfusion-related acute lung injury, and fluid overload 3
• Do not delay restarting antiplatelet therapy after bleeding control - resume at least single agent within 24-48 hours 1, 5
• Avoid complete anticoagulation reversal unless absolutely necessary - the prothrombotic state in dengue may paradoxically increase stent thrombosis risk 1

Supportive Care Measures

• Maintain adequate hydration to prevent hemoconcentration 3, 4
• Proton pump inhibitor therapy (pantoprazole or dexlansoprazole) to reduce GI bleeding risk 7
• Avoid NSAIDs and IM injections 3
• Blood pressure control to minimize bleeding risk 1

Resumption Strategy Post-Dengue Recovery

Once platelet count recovers >50,000/μL and no active bleeding:

• Resume full DAPT immediately if within 6 months of PCI 1, 8
• Continue DAPT for the originally planned duration based on PCI indication 1, 8
• If severe bleeding occurred requiring DAPT interruption >5 days, consider extending DAPT duration 1