Stopping stent restenosis

[johnnybgood75]

Hi. My wife has had 3 angioplasties, the 1st in 2001, the second in 2008 and the last this year (2009). The procedure in 2008 resulted in restenosis of a stent and caused her to return in 2009. It seems that restenosis is occurring again as her chest pain is beginning to return.

We have already modified our diet and lifestyle and feel that apart from the issue of restenosis we probably have the heart disease under control.

Does anyone know of any way to stop or reverse restenosis which has already begun in a stented artery? We would like to find some way to do this so as to avoid the trauma of another invasive angioplasty or bypass surgery.

Thanks,

Johnny

[kenkeith]

QUOTE: "When Plavix is stopped, the surface of the stent can still be too rough and clotting will form."  

>>>>>Clotting forms when there is a rupture of the soft plaque within the lining of the vessel into the lumen, and other causes given below. A rough area does not cause a clot...it causes plaque due to shear stress, blood flow turbulence and gradient pressures of an uneven surface.

I stated on this forum and I don't see any changes except may be the delivery system..
by kenkeith, Aug 29, 2008 03:58PM
To: omi123
For a perspective when a stent is placed in a blood vessel, new tissue grows inside the stent, covering the struts of the stent. Initially, this new tissue consists of healthy cells from the lining of the arterial wall (endothelium). This is a favorable effect because development of normal lining over the stent allows blood to flow smoothly over the stented area without shear stress, etc. Later, scar tissue may form UNDERNEATH the new healthy lining.

In about 25% of patients, the growth of scar tissue underneath the lining of the artery may be so thick that it can obstruct the blood flow and produce an important blockage. In-stent restenosis is typically seen 3 to 6 months after the procedure; after 12 months have passed uneventfully, it is rare.  
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Some injury almost always occurs to the artery  during stent placement. This can trigger a healing process where scar tissue collects on the inside of the stent, making the stented vessel narrow again. It is most likely to occur in SMALL vessels, LONG stents and in people with diabetes. Most DES elute their drug in the first three months, which is the period when scar tissue typically forms in bare metal stents.

Drug "eluting" stents have now been developed to STOP  the growth of the scar tissue. They use a small amount of immunosuppressive drug loaded on to the stent to prevent vascular smooth muscle cells dividing and proliferating the neointima..

The thrombosis is controlled using anti-platelet therapy. However, BMS are not immune from restenosis, primarily by neointimal (thin covering over the intima) HYPERPLASIA is caused from the ripping of the vessel during balloon expansion and exposure of the vessel’s smooth muscle cells (this causes blood clots, not an irregular surface).

While DES significantly reduce restenosis compared to BMS rates, studies found DES have increased rates of late-stent thrombosis, believed to be caused by the drug delivery polymer irritating the vessel. The rate of thrombosis is below 1 percent, but this finding prompted the American College of Cardiology to post guidelines suggesting 12 months of anti-platelet therapy after DES implantation (another cause for clots).

Although stents provide a less invasive method of treatment or repair as opposed to surgery, they do possess one major disadvantage. As the area around the stent heals, the scar tissue that accumulates often invades the area held open by the stent and causes the area to occlude with scar tissue. This process is called reactive fibrosis . Oftentimes, in these cases, smaller stents are placed inside the original larger stents in order to open up a stent occluded with scar tissue

For a statistic,.... now most people, approximately two thirds, will get a thin little scar or scab inside the artery, and that heals the artery very nicely. But approximately a third of patients will have an excessive amount of scar or scab form, given the size of the artery, because these arteries are actually quite small, and that will gradually re-narrow the artery within the first six or twelve months, and that's what is called  re-stenosis.
Risk for blood clots (not irregular surface!).  we know that the likelihood of the arteries re-narrowing after drug-eluting stents are much less than after bare metal stents, but these are very potent compounds, and sometimes they cause the artery to heal to a minimal degree. And, as a result, occasionally blood clots can form on drug-coated stents.

The end! :)

[ed34]

Well not quite the end. All this worry about clotting and restenosis should be a thing of the past by now. Where are the third generation stents?
Aren't we supposed to have bioresorbable stents by now? These sit in a vessel and slowly dissolve harmlessly away, leaving a perfectly healed and healthy artery. No clot problems, no restenosis problems. No worries about the artery collapsing.
I thought they were going to be introduced by 2009?

[kenkeith]

QUOTE: "Too fast for most patients to even realise something has gone wrong and fatalaties have occurrred. Many Cardiologists still argue that patients who receive DES should stay on Plavix indefinitely until these problems are more understood and addressed.
Oh and how quickly can clotting block an artery when Plavix is stopped? in a matter of several minutes, it's that quick".
>>>>> I don't believe half what you state in your post, but do you mind providing source for the above, and i will go from there.  I have asked for a source in other postings,  and you fail to provide, so I'm beginning to believe you are making up information.

Yes, we know there are biodegradable stents in the future or so they say.  Also, a stent platform such as a bifurgation stent.  That is a new chapter so lets focus on the present and you can start by supplying your source for your rhetoric.

[cblmn7]

my cardiogist told me im on plavix and asprin for the rest of my life. how come if after a year thedrug in the des is gone. just wondering. i have been told by 3 different drs that i have too.

[kenkeith]

QUOTE: "my cardiogist told me im on plavix and asprin for the rest of my life. how come if after a year thedrug in the des is gone. just wondering. i have been told by 3 different drs that i have too".    

The easy answer is the doctor believes the risk of excessive bleeding doesn't outweigh the risk of cardiovscular event. Tests are continuing regarding restenosis, clots, etc. with the last test there were some agreement to discontinue Plavix after a year or so as that period of time seems to be the most vulnerable for blood clots...maybe longer for diabetics. The following governemnt trial study indicates a higher risk for a heart attack if Plavix is discontinued.

"A recent trial government trials that shows after clopidogrel (plavix) discontinuation patients receiving drug-eluting vs bare-metal stents experienced higher rates of death and MI (4.9% vs 1.3%, respectively). These results have created uncertainty regarding the minimal necessary duration of antiplatelet therapy after drug-eluting stent implantation. Also, there remains widespread uncertainty regarding the risk of clinical events after the discontinuation of clopidogrel, particularly after DES implantation".

For referrence:

NCT00590174 on 2008_01_09
ClinicalTrials Identifier: NCT00590174
Updated: 2008_01_09
Descriptive Information
Brief title Clopidogrel Use and Long-Term Safety After Drug-Eluting Stents Implantation

Official title Evaluation of the Long-Term Safety After Zotarolimus-Eluting Stent, Sirolimus-Eluting Stent, or PacliTaxel-Eluting Stent Implantation for Coronary Lesions - Late Coronary Arterial Thrombotic Events

Trial study:
The purpose of ZEST-LATE (Evaluation of the Long-term Safety After Zotarolimus-Eluting Stent, Sirolimus-Eluting Stent, or PacliTaxel-Eluting Stent Implantation for Coronary Lesions - Late Coronary Arterial Thrombotic Events) trial is to assess the relationship between long-term clopidogrel use beyond 1 year and long-term rates of death or MI after DES implantation and to estimate the duration of dual antiplatelet therapy for preventing the late thrombotic events.

Detailed description:
Instructions for the use of drug-eluting stents (DES)commercially available in the worldwide specify treatment with clopidogrel for at least 3 months (for sirolimus-coated stents) or 6 months (for paclitaxel-coated stents) after implantation. Premature discontinuation of this minimum antiplatelet therapy has been associated with stent thrombosis. However, studies of late thrombosis events among patients with a drug-eluting stent have cast doubt on whether the recommended regimens are sufficient. An observational analysis from BASKET-LATE (Basel Stent Kosten-Effekivitats Trial-Late Thrombotic Events) examined the incidence of clinical events after cessation of clopidogrel therapy. This study identified 746 patients who were without major adverse events 6 months after drug-eluting or bare-metal stent placement. All patients had stopped taking clopidogrel and were followed up for an additional 12 months. At 18-month follow-up, there was no difference between patients with a drug-eluting or bare-metal stent in cumulative rates of death or myocardial infarction (MI). However, after clopidogrel discontinuation patients receiving drug-eluting vs bare-metal stents experienced higher rates of death and MI (4.9% vs 1.3%, respectively). These results have created uncertainty regarding the minimal necessary duration of antiplatelet therapy after drug-eluting stent implantation. Also, there remains widespread uncertainty regarding the risk of clinical events after the discontinuation of clopidogrel, particularly after DES implantation.
Therefore, this study is designed to evaluate the relationship between clopidogrel use and long-term rates of cardiac death or MI after DES implantation.


  

                        


            
    
  

[kenkeith]

QUOTE: "Too fast for most patients to even realise something has gone wrong and fatalaties have occurrred. Many Cardiologists still argue that patients who receive DES should stay on Plavix indefinitely until these problems are more understood and addressed.
Oh and how quickly can clotting block an artery when Plavix is stopped? in a matter of several minutes, it's that quick".
>>>>> I don't believe half what you state in your post, but do you mind providing source for the above, and i will go from there.  I have asked for a source in other postings,  and you fail to provide, so I'm beginning to believe you are making up information.