Heparin-Induced thrombocytopenia (HIT) & Percutaneous coronary intervention (PCI)

Percutaneous coronary interventions (PCIs) are an important group of technologies for the diagnosis and treatment of patients with cardiovascular disease. In addition to balloon angioplasty, PCI now includes other new techniques capable of relieving coronary narrowing, including[37]:

•	Intracoronary stents are placed in the majority of PCI patients
•	Various forms of atherectomy are occasionally performed (eg, rotational, directional, extraction, laser)

More than 500,000 interventional procedures are performed annually in the United States, and it has been estimated that more than 1 million procedures are performed worldwide.[37]

Intensive anticoagulation is a critical requirement during PCI to reduce the risk of thrombosis. Heparin is used in virtually all interventional coronary procedures as it has been shown to prevent clot formation at the site of arterial injury and on the hardware used in PCI. [37]

Unfortunately, the use of heparin has the potential to increase the occurrence of HIT. The hypercoagulable state characterizing HIT plus the endovascular disruption resulting from PCI may place patients with HIT at particular risk of thrombosis during PCI.[4] Heparin is contraindicated in HIT patients and the use of LMWH and danaparoid are also contraindicated because both cross-react with HIT antibodies.