Severe intracranial hemorrhage after emergency carotid stenting and abciximab administration for postoperative thrombosis

Thrombocytopenia following percutaneous coronary intervention

BACKGROUND

Thrombocytopenia following percutaneous coronary intervention (PCI) is an underappreciated condition that is often clinically challenging. There are no guidelines on the management of patients with this condition.

OBJECTIVE

To review recent data in etiologies, risk factors, prevention, management, and prognostic implications of thrombocytopenia following PCI.

EVIDENCE ACQUISITION

Search of MEDLINE, EMBASE, the Cochrane Database, and Google Scholar using the term thrombocytopenia + PCI and other relevant keywords to identify systematic reviews, clinical trials, cohort studies, case series, and case reports. The review was limited to English-language articles published between January 1980 and June 2009. Articles on patients with baseline thrombocytopenia prior to PCI were excluded.

EVIDENCE SYNTHESIS

Thrombocytopenia is not infrequent following PCI. The typical patient with post-PCI thrombocytopenia is on multiple therapies that can potentially cause a decrease in the platelet count. Identification of the cause is critical because management of the condition varies significantly based on the etiology. The severity of the thrombocytopenia also determines the clinical management of the patient. Several observational studies have demonstrated the adverse prognostic impact of the complication on clinical outcomes and have identified risk factors.

CONCLUSIONS

Judicious use of therapies that can cause thrombocytopenia, efficient detection of the cause of the decrease in platelet count, and appropriate management of the condition can potentially improve the quality of care and outcomes following PCI. Further research into risk factors that predispose post-PCI patients to developing thrombocytopenia is warranted.

Glycoprotein IIb/IIIa antagonists during carotid artery stenting:

BACKGROUND

Glycoprotein II b/IIIa antagonists (GPII b/IIIa-A) lower the periprocedural rate of ischemic events during high risk percutaneous coronary interventions. Their clinical impact on carotid artery stenting (CAS) remains to be determined.

METHODS

We analyzed data from the Carotid Artery Stent (CAS) Registry.

RESULTS

From 01/ 2000 to 06/2005 1322 CAS interventions were registered. In 94 (7.1%) procedures a GPII b/IIIa-A was used: abciximab in 8 cases (8.6%), tirofiban in 53 cases (57%) and eptifibatide in 32 cases (34.4%). The use of a GPII b/IIIa-A during CAS decreased significantly over time: from 17.6% in 2000 to 3% in 2005, p for trend <0.0001. The mean use of a GPII b/IIIa-A at the hospitals was 5.2%. More than 50% of the hospitals never used a GPII b/IIIa-A. There were no significant differences in baseline characteristics and concomitant diseases in CAS patients treated with GPII b/IIIa-A compared to those without GPII b/IIIa-A. A bilateral intervention was performed more often in patients treated with GPII b/IIIa-A (2.1 vs 0.2%, p = 0.04), a thrombus was more often visible (27 vs 12.4%, p <0.001) and an ulcer more frequently diagnosed (50 vs 37.5%, p = 0.03). There was no significant difference in the combined death or stroke rate between the two groups (5.3 vs 3.0%, p = 0.22, OR = 1.81, 95% CI: 0.69-4.72), which was confirmed by logistic regression analysis after adjusting for possible confounders (OR = 1.67, 95% CI: 0.62-4.46, p = 0.31).

CONCLUSIONS

Our data neither demonstrate a significant benefit nor a significant risk with the use of GPIIb/IIIa-A during CAS. However, only an adequately sized randomized controlled clinical trial could establish the real value of GPII b/IIIa-A during CAS. Until then, considering the potential increase in cerebral hemorrhage, we should not use GPII b/ IIIa-A routinely during CAS.

Glycoprotein IIb/IIIa inhibitor-induced thrombocytopenia

Thrombocyte glycoprotein IIb/IIIa inhibitors prevent fibrinogen binding and thereby thrombocyte aggregation. The inhibition of thrombocyte activation at the damaged coronary plaque is the target of the new therapeutic strategies in treating acute coronary syndrome. This reduces the ischemic complications associated with the non-STelevation myocardial infarction (NSTEMI) and percutaneous coronary intervention (PCI). Thrombocytopenia is a known complication of glycoprotein (GP) IIb/IIIa inhibitors. Although, in general, GP IIb/IIIa inhibitor-induced thrombocytopenia is a harmless side effect which responds readily to thrombocyte transfusion, it can occasionally be a very serious complication associated with serious bleeding. In addition patients developing thrombocytopenia have unfavorable outcome (e.g., death, myocardial infarction, bypass surgery or additional PCI) in comparison to patients without thrombocytopenia. Advanced age (> 65 years), low BMI and a low initial thrombocyte count (<180,000/microl) are independent risk factors of thrombocytopenia. The risk of bleeding is higher with this form of thrombocytopenia not only due to the low thrombocyte count but also to the impaired function of the remaining thrombocytes. It is important to closely monitor platelet count during GP IIb/IIIa antagonist treatment. Platelet count monitoring two, six, twelve and 24 hour after starting the treatment reveals most cases of acute thrombocytopenia. Side effects can be avoided by the early discontinuation of the GP IIb/IIIa antagonist treatment. This article reviews the diagnosis and treatment of glycoprotein IIb/IIIa inhibitor-induced thrombocytopenia and summarizes the differential diagnosis from heparin-induced thrombocytopenia and laboratory-related pseudothrombocytopenia.

Successful Recanalization by In-Stent Percutaneous Transluminal Angioplasty With Distal Protection for Acute Carotid Stent Thrombosis-Case Report-

A 71-year-old male presented with severe left cervical internal carotid artery stenosis manifesting as repeated transient ischemic attacks consisting of right hemiparesis and motor aphasia. Carotid artery stenting (CAS) under distal protection was performed to prevent further ischemic events. This procedure was uneventful. However, the patient exhibited progressive right hemiparesis and motor aphasia 3 days after CAS. Emergent angiography revealed carotid artery occlusion due to in-stent thrombosis. In-stent percutaneous transluminal angioplasty (PTA) was performed under distal protection. The carotid artery was recanalized with small residual thrombus. The neurological deficits almost completely disappeared after PTA. Follow-up angiography 9 months after stenting showed restenosis but no in-stent thrombosis. Carotid thrombosis after CAS can be resolved by in-stent PTA under distal protection and subsequent treatment with antithrombotic agents.

Immune thrombocytopenia caused by glycoprotein IIb/IIIa inhibitors

Agents that react with the platelet glycoprotein (GP) IIb/IIIa complex (alphaIIb/beta3 integrin) to block fibrinogen binding and platelet-platelet aggregation have been proved to be effective in reducing the incidence of complications following coronary angioplasty and are now widely used for this purpose. Acute thrombocytopenia, which is sometimes severe and life-threatening, is a recognized side effect of this class of drugs. In contrast to other types of drug-induced thrombocytopenia, this complication can occur within a few hours of a patient's first exposure to the medication. Accumulating evidence has indicated that drug-dependent antibodies, which can be naturally occurring, are the cause of platelet destruction in such individuals. In this review, we will consider the clinical aspects of thrombocytopenia resulting from sensitivity to GPIIb/IIIa inhibitors and will review evidence that the platelet destruction is antibody-mediated.