# Case Report: Heparin-induced thrombocytopenia leads to acute myocardial infarction post-PCI in multi-vessel coronary artery disease

## TL;DR

A 58-year-old man with heart disease developed a dangerous blood clot after a heart procedure due to a rare heparin side effect.

## Contribution

This case report highlights the challenges of diagnosing and managing heparin-induced thrombocytopenia in post-PCI patients.

## Key findings

- The patient developed acute myocardial infarction following PCI and was suspected of HIT due to a significant drop in platelet count.
- The patient received a contraindicated platelet transfusion during transfer, leading to a fatal arrhythmic event.
- The case emphasizes the need for timely diagnostic testing and proper communication during hospital transfers to avoid harmful interventions.

## Abstract

Heparin-induced thrombocytopenia (HIT) is a rare but severe complication of heparin therapy, characterized by a significant reduction in platelet count and a paradoxical prothrombotic state, which increases the risks of both arterial and venous thrombosis. This case report describes a 58-year-old male patient with multi-vessel coronary artery disease who developed acute ST-segment elevation myocardial infarction (STEMI) following successful percutaneous coronary intervention (PCI). Despite initial successful revascularization, the patient experienced recurrent chest pain, and HIT was clinically suspected based on a significant drop in platelet count and the 4Ts scoring system, though confirmatory anti-PF4/heparin antibody testing was unavailable at our institution. Treatment with corticosteroids was initiated; however, following transfer to another hospital, the patient received platelet transfusion—a contraindicated intervention in HIT—and subsequently succumbed to a fatal arrhythmic event. This case highlights the diagnostic and therapeutic challenges of suspected HIT in PCI patients, where it may mimic other post-procedural complications such as stent thrombosis. It underscores the critical need for vigilant monitoring of platelet counts, timely access to confirmatory diagnostic testing, immediate initiation of guideline-recommended non-heparin anticoagulants, and seamless communication during inter-hospital transfers to prevent potentially harmful interventions and improve patient outcomes.