Stent thrombosis

A stent thrombosis is an acute thrombotic occlusion of an artery within an implanted stent . It leads to a sudden circulatory disturbance and is therefore a potentially life-threatening event.

Pathogenesis

In the treatment of arterial stenoses and occlusions, stents are used to keep the treated area permanently open after dilation with a balloon. After implantation , the stent is overgrown by endothelial cells . Until this has happened, it lies free in the blood vessel. When the blood comes into contact with the foreign body, clotting processes can take place, which typically begin with the accumulation and aggregation of platelets . A thrombus forms . This can relocate the stent or be carried away by the bloodstream ( embolism ). The result is often an interruption in the blood flow and ischemia of the tissue supplied by the artery . In contrast to stent stenosis, this happens very quickly, which leads to more pronounced tissue damage .

Temporal classification of (coronary) stent thrombosis:

1. Early stent thrombosis (0-30 days after stent placement)
   • acute stent thrombosis (within the first 24 hours after stent placement)
   • subacute stent thrombosis (days 1–30 after stent implantation)
2. Late stent thrombosis (> 30 days after stent placement)
3. Very late stent thrombosis (> 12 months after stent placement)

consequences

The consequences of a stent thrombosis mainly depend on which organ provides for the affected artery:

organ	possible consequence of ischemia
heart	Heart attack
brain	Cerebral infarction ("ischemic stroke")
Intestines	Mesenteric infarction
extremities	acute peripheral artery occlusion , gangrene

The extent of the damage may depend on a. on the size of the affected tissue area, the sensitivity of the tissue and any collaterals that may be present .

therapy

The therapy consists primarily in reopening the closed vessel ( revascularization ). The time between the onset of occlusion and revascularization (ischemia time) is decisive for the question of how much tissue damage can be avoided.

Situation with drug eluting stents

Drug-coated stents (also known as drug eluting stents or DES) release active substances that are intended to prevent the stent from being closed again after implantation due to proliferation processes. It has been shown that patients who have received such a stent suffer more frequently from stent thrombosis than patients with an uncoated stent (bare metal stent, BMS). This is probably mainly due to the fact that the drugs released by the stent delay the healing process (overgrowing endothelium ). Inflammatory processes with the accumulation of fibrin also play a role.

prophylaxis

To prevent stent thrombosis, two different drugs are given to inhibit platelet aggregation ("dual platelet inhibition"). The German Society of Cardiology in line with the recommended European Society of Cardiology permanent therapy with acetylsalicylic acid (ASA). A second drug such as clopidogrel , ticagrelor or prasugrel is given for this purpose. The duration of the combined prophylaxis depends on the type of stent and the indication of the stent implantation. A minimum of 12 months is recommended for drug-coated stents and 1 month for uncoated stents. After stent implantation in the context of an acute coronary syndrome , combined prophylaxis should be carried out for at least 12 months.

Individual evidence

1. ↑ DE Cutlip u. a .: Clinical end points in coronary stent trials: a case for standardized definitions. In: Circulation , 2007, 115, pp. 2344-2351. PMID 17470709
2. ↑ J. Fajadet, A. Chieffo: Current management of left main coronary artery disease. In: Eur Heart J . (2012) 33, pp. 36-50. PMID 22210689
3. ↑ ^{a b} T. Takayama et al. a .: Stent thrombosis and drug-eluting stents. In: J Cardiol. (2011); 58, pp. 92-98. PMID 21839615
4. ↑ escardio.org ( memento of July 4, 2013 in the Internet Archive ) accessed on July 4, 2013.
5. ↑ M. Pfisterer et al. a .: Late clinical events after clopidogrel discontinuation may limit the benefit of drug-eluting stents: an observational study of drug-eluting versus bare-metal stents. In: J Am Coll Cardiol . (2006) 48, pp. 2584-2591. PMID 17174201
6. ↑ T. Palmerini et al. a .: Stent thrombosis with drug-eluting and bare-metal stents: evidence from a comprehensive network meta-analysis. In: The Lancet . (2012) 14, pp. 1393-1402. PMID 22445239
7. ^ Medication-releasing coronary stents and balloon catheters coated with medication. Position paper of the DGK. (PDF) German Society for Cardiology, 2011, accessed on June 5, 2012 . 
8. ↑ Guidelines on myocardial revascularization. European Society of Cardiology (ESC), 2014, accessed on March 3, 2016 . 

This article is about a health issue. It is not used for self-diagnosis and does not replace a diagnosis by a doctor. Please note the information on health issues !