Diagnosing coronary arterial stent thrombosis and arterial closure

Subacute Stent Thrombosis in Intracranial Stenting

Background and Purpose— We sought to determine the safety of intracranial stenting with respect to subacute stent thrombosis in patients being treated with standardized antiplatelet therapy.

Methods— We retrospectively evaluated the outcome of primary intracranial stenting of atherosclerotic stenoses and of stenting in coil embolization procedures in 67 patients. We focused on those cases that led to subacute stent thrombosis even though the patients had been treated with standardized antiplatelet therapy before, during, and after stent placement. Patient age ranged from 19 to 78 years. In 33 patients, stents were placed for treatment of atherosclerotic stenoses; in the remaining 34 patients, stents were placed to assist coiling of aneurysms. The patients in this study were treated between January 2003 and August 2007.

Results— Of the total 67 patients initially treated successfully by intracranial stenting, 7 patients developed subacute stent thrombosis. Of these 7 patients, 3 received stent placement into the basilar artery because of an underlying stenosis; in 1 patient, a stenosis of the M1 segment of the middle cerebral artery was treated. In 3 patients, aneurysms of the anterior cerebral artery, the posterior inferior cerebellar artery, and the basilar artery were treated by stent-assisted coil embolization. In 4 of the 7 patients with subacute thrombosis, recanalization of stents by local application of recombinant tissue-type plasminogen activator was successful.

Conclusions— Intracranial stenting can lead to subacute stent thrombosis, even in patients who are treated with standardized antiplatelet therapy. Such complications have been described for patients after coronary artery stenting, but to our knowledge, no one has reported on a comparable number of cases of intracranial stenting procedures. In certain clinical scenarios, local thrombolysis with recombinant tissue-type plasminogen activator is an important treatment option to deal with subacute stent thrombosis.

Incidence of coronary stent thrombosis based on academic research consortium definitions

Stent thrombosis occurs infrequently after drug-eluting stent (DES) placement, but concerns have surfaced that identification of stent thrombosis based solely on angiography may underestimate the true incidence of this complication. The purpose of this study was to compare rates of stent thrombosis using Academic Research Consortium (ARC) definitions. From April 2002 to February 2005, bare-metal stents (BMSs) and DESs were placed at Wake Forest University Baptist Medical Center. Rates of ARC definite, probable, and possible stent thrombosis were evaluated. Overall, definite stent thrombosis occurred in 1.4% of BMSs and 1.1% of DESs (p = 0.47); probable stent thrombosis, in 1.0% of BMSs and 0.9% of DESs (p = 0.81); definite plus probable stent thrombosis, in 2.3% of BMSs and 1.9% of DESs (p = 0.48); and possible stent thrombosis, in 6.8% of BMSs and 3.5% of DESs (p <0.001). Rates of definite late (31 days to 1 year) and very late (>1 year) stent thrombosis were 0.9% for BMSs and 0.06% for DESs (p <0.001) and 0.16% for BMSs and 0.56% for DESs, respectively (p = 0.13). Rates of definite plus probable and late and very late stent thrombosis were 1.1% for BMSs and 0.19% for DESs (p <0.001) and 0.40% for BMSs and 0.68% for DESs, respectively (p = 0.31). Rates of possible stent thrombosis increased significantly for each thrombosis interval. In conclusion, rates of stent thrombosis using the proposed ARC definition differed by stent type, definition of stent thrombosis, and thrombosis interval. Use of the ARC probable stent thrombosis paralleled rates of definite stent thrombosis alone, but partially masked the occurrence of late (>1 year) stent thrombosis in DESs compared with BMSs.