Postprocedural low molecular weight heparin in patients at high risk of subacute stent thrombosis

Subacute stent thrombosis (SAT) is a dramatic complication of percutaneous coronary stenting occurring in 0.4-20% of cases depending on several angiographic and clinical variables. The role of postprocedural low molecular weight heparin (LMWH) in preventing early events after high-risk PCI is not well established. In this study we describe our experience with postprocedural LMWH in patients deemed to be at high risk of SAT.

Thirty-six patients who were treated with subcutaneous LMWH for at least 7 days after the intervention were identified from our database. All cineangiograms and charts were retrospectively reviewed to confirm the high-risk intervention properties. Thirty-day and long-term major adverse coronary events (MACEs) were documented in all patients.

The most common indications for LMWH were the deployment of > or =3 consecutive stents, the presence of intracoronary thrombus or ulceration, poststenting residual stenosis, contraindication to aspirin or thienopyrideines, and persistent dissection. The majority of patients (61%) had > or =2 risk factors. Mean postprocedural treatment period was 12+/-3 days. At 30 days, none of the patients experienced a MACE including death, myocardial infarction, and repeat revascularization. No major bleeding occurred and one patient (2.7%) had a minor bleeding. At a mean follow-up of 31 months, MACE occurred in 17% of patients.

Postprocedural LMWH is safe and effective in preventing SAT in patients undergoing high-risk coronary intervention.