SEVERE THROMBOCYTOPENIA POST PCI: HEPARIN-INDUCED VS GP IIB/IIIA INHIBITOR-INDUCED

Background: Thrombocytopenia is a clinically relevant complication in patients undergoing Percutaneous Coronary Intervention (PCI) or treated for Acute Coronary Syndrome (ACS), particularly following the use of anticoagulant and antiplatelet agents. Heparin and glycoprotein (GP) IIb/IIIa inhibitors are frequently implicated, but the comparative clinical patterns and outcomes between these drug-induced etiologies remain inadequately explored. Objective: To evaluate the incidence, severity, duration, and clinical outcomes of severe thrombocytopenia in PCI/ACS patients, with specific comparison between heparin-induced and GP IIb/IIIa inhibitor-induced thrombocytopenia. Methods: A prospective observational study was conducted at Shifa International Hospital, Islamabad, from September 2024 to March 2025. A total of 58 patients who developed severe thrombocytopenia (platelet count <50,000/μL) following PCI or ACS management were enrolled. Patients were classified into two groups based on exposure to either heparin or GP IIb/IIIa inhibitors. Clinical data including demographics, comorbidities, antithrombotic regimens, platelet trends, and bleeding events were recorded. Outcomes such as thrombocytopenia duration, recovery time, and complications were statistically analyzed using SPSS v27, with significance set at p<0.05. Results: Among 58 patients, 32 (55.2%) had heparin-induced thrombocytopenia (HIT), and 26 (44.8%) were linked to GP IIb/IIIa inhibitors. Mean age was 65.2 ± 8.1 years; 72.4% were male. Hypertension was the most prevalent comorbidity (48.3%). All HIT patients received heparin, while 100% of GP IIb/IIIa cases received bivalirudin (p<0.001). Duration of thrombocytopenia was longer in the HIT group (11.8 ± 3.5 days) compared to GP IIb/IIIa group (9.2 ± 2.8 days, p=0.014). Recovery time was significantly extended in HIT patients (8.5 ± 2.8 vs. 5.6 ± 1.9 days, p<0.001). Severe bleeding occurred in 25.0% of HIT patients versus 7.7% in the GP IIb/IIIa group (p=0.083). Conclusion: While incidence and severity of thrombocytopenia were comparable across both groups, heparin-induced cases demonstrated a more prolonged course and higher bleeding tendency, highlighting the need for agent-specific monitoring and tailored management strategies.