Six to 12 months is the right timeframe for dual antiplatelet therapy

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During the Great Debate at this year’s EuroPCR (21–24 May, Paris, France), leading experts in interventional cardiology discussed the use of dual antiplatelet therapy (DAPT) after percutaneous coronary intervention (PCI). The key issues raised were the optimum duration of DAPT with second-generation, drug-eluting stents and the use of new, more potent, antiplatelets.

The focus of the discussion was how the speakers would manage a stable patient with evidence of a tight distal stenosis in the left main artery. Robert Byrne (Deutsches Herzzentrum Munchen, Berlin, Germany) said that the European Society of Cardiology (ESC) recommended that DAPT (with aspirin and clopidogrel) be continued for six to 12 months in stable patients who have undergone PCI with a drug-eluting stent. He added: “I think that, probably, we will never have a randomised controlled trial that definitively tells us which subset of patients should receive DAPT for six months and which subset should receive it for 12 months. We have to look at the risks of bleeding vs. the risk of stent thrombosis.

Unfortunately, risk factors for bleeding and those for stent thrombosis tend to cluster on the same patient; therefore, a patient who has a high risk of bleeding may also have a high risk of stent thrombosis. At the end of the day, it comes down to your clinical judgement.”

Andreas Baumbach, Bristol Heart Institute, Bristol, UK, added that the CURE (Clopidogrel in  unstable angina to prevent recurrent events) study was the reason why guidelines—and many interventional cardiologists—recommended that DAPT should be continued up to 12 months in patients with non-ST segment elevation myocardial infarction (NSTEMI) acute coronary syndromes. He said: “If you look at the data from CURE, you see that the curves between DAPT and single therapy after PCI keep separating. So there is at least an anti-ischaemic benefit of prolonging DAPT to 12 months. The CURE investigators stopped at 12 months, which is why we stop at 12 months.”

Baumbach commented that he would continue to recommend DAPT for six to 12 months in patients who had received a second-generation drug-eluting stent. Recently, after new data were published, the CE marking changed for both Medtronic’s zotarolimus-eluting stent (Resolute) and Abbott Vascular’s everolimus-eluting stent (Xience) allowing DAPT to be stopped, respectively, after one and three months. He said: “I think there has been a slight miscommunication about these changes. The studies behind them reviewed interruption of treatment; they did not evaluate planned discontinuation of treatment. So unless we have definitive trial data that shows planned discontinuation of one month or three months is safe, I do not think we can to stop at this time. However, I am now much more comfortable with stopping DAPT in patient with a new stent who has a bleed at three or four months or who needs an operation.”

Choice of antiplatelets

As well as discussing second-generation drug-eluting stents, the speakers at the debate also reviewed the use of new antiplatelets (ie. prasugrel or ticagrelor). Ibrahim Al Rashdan (Kuwait Heart Center, Chest Hospital of Kuwait, Kuwait City, Kuwait) said: “New antiplatelet therapies add value to our existing armamentarium in the cath lab. We do not have prasugrel in the Middle East but we do have ticagrelor, and we found that patients who were treated with ticagrelor had less stent thrombosis and less mortality. Therefore, in this particular case [ie. the aforementioned stable patient with left main disease], I would definitely use ticagrelor and aspirin. If cost is an issue, as the greatest benefit of new antiplatelets is seen in the first month, you could use ticagrelor for a month and then switch to clopidogrel.”

Chaim Lotan (Hadassah-Hebrew University Medical Center, Jerusalem, Israel) noted that individual patient characteristics had to be taken into consideration when choosing whether to use a new antiplatelet or not. He said: “Who is the patient? What are their risk factors? Is he diabetic? What is the size and length of the stent that you will be using? Our role is to take everything into consideration when choosing antiplatelet therapy.”  Lotan added that he would use one of the new antiplatelets in patients who had a higher degree of stenosis even if they were stable.

Responding to a question about how he would treat a patient who was allergic to aspirin, Baumbach reported: “The first thing to ask is it a true allergy? Can we re-expose them to aspirin and see if something happens? If it was a true allergy and the patient was operable, I would swing towards surgery. It is too much of a risk to put a patient onto a treatment regimen (ie. without aspirin) that might not be anti-ischaemic enough.” However, he added that the concept of monotherapy would emerge into the next two or three years, saying: “We will not be talking about prasugrel or ticagrelor plus aspirin; we will be talking about prasugrel or ticagrelor alone and that would solve the problem of patients who cannot take aspirin.”

Lotan stated that while the additional benefit of the aspirin was small, “no one wants to do a study without it.” He added: “I suspect with the new antiplatelets, the additional benefit of aspirin is very small and when people ask which treatment should be stopped first with triple therapy, definitely aspirin could be stopped.”

The unstable patient

The panel also discussed managing patients with ST-segment elevation myocardial infarction (STEMI). Christoph Naber (Contilia Heart and Vascular Center, Essen) commented: “If it is a STEMI patient, everything changes as we now have a life-threatening event. We do not need to think about stent thrombosis at first as the more important thing is to reduce recurrent events.”

The panel was chaired by Martyn Thomas (St Thomas’ Hospital, London, UK) and Michael Haude (Städtische Kliniken Neuss, Lukaskrankenhaus GmbH, Dusseldorf, Germany).