This transcript has been edited for clarity.
This is part two of our Medscape UK EuroPCR presentation, and today I'm going to talk about two important studies around interventional cardiology. The first study that we're going to talk about is on anti-platelet use, particularly in complex groups of patients. And we're going to focus around a sub-study of the global leaders trial that was presented at EuroPCR. The second study that we're going to talk about is what we do and how we treat patients with small vessel coronary artery disease, which is increasingly common in our practice.
Again, focusing around the theme of PCI and complex groups of patients, a very interesting trial was the BIO-RESORT small vessel sub study. In PCI, we often encounter patients with small coronary arteries, defined as vessels less than 2.5 mm diameter, such as elderly patients, women, and also patients with diabetes. And it's often been a challenge how best to optimally treat these vessels, particularly small calibre. The reason being that they have a small MLA [minimum lumen area] and so if you use a thick strutted stent or platform, then you're more likely to compromise the MLA compared to using a thinner platform.
And so in this retrospective analysis of a randomised controlled trial, the BIO-RESORT trial, they analysed a strategy of three different types of stent - the ultra-thin stent, which is the Osiris sirolimus-eluting stent, the very thin stent, which is the everolimus Synergy stent, and the thin stent, which is the zotarolimus-eluting stent.
And what they looked at was target lesion failure, which they refer to as cardiac death, target vessel-related myocardial infarction, and target lesion revascularisation. And what they found was that there was certainly, in the earlier time points, a signal towards better outcomes with the very thin or ultra-thin platforms compared to the regular zotarolimus-eluting Medtronic stent.
At the 3-year time point target lesion revascularisation was significantly lower in the ultra-thin platform compared to the zotarolimus-eluting stent.
So what does that mean for practice? Well, certainly taken at face value, we should be thinking about strut thickness in treating patients with very small coronary arteries. I think this is important. Why? Because up to half of the patients in the BIO-RESORT trial had small vessel disease as defined by a vessel diameter less than 2.5 mm.
I think this trial should be interpreted with some caution, however, because remember that we're comparing three different types of stents with three different types of drugs, with three different types of polymers. And we know that both polymers, as well as the drug that's used, can impact on target lesion failure.
So what this trial doesn't do is really bring out whether it's a stent thickness-related benefit to the endpoint, or whether it's related to one of the other factors, ie drug or polymer.
I think the other thing to think about when undertaking PCI in small vessels is the assessment of vessel calibre. Often when you do intra-vascular imaging such as a CT, what you find is that what looks like a small vessel, in fact, isn't a small vessel, it's just because the patient has significant atherosclerosis. And if you adequately size your stent with intravascular imaging, you find that you end up using a lot bigger stents than the 2.5 mm that you were initially going to use.
So I think this is an important hypothesis-generating trial but I think definitely more data is required in this space.
GLOBAL LEADERS Study
The final study will be GLOBAL LEADERS study. So this was a large study from over 130 sites, 18 different countries, and this was initially published last year. And this randomised patients to one of two treatment strategy arms with regards to antiplatelet therapy.
The first treatment strategy arm was conventional therapy in patients with ACS [acute coronary syndrome] or stable angina. And the experimental arm was randomised to 1 month of dual antiplatelet therapy (DAT) with aspirin and ticagrelor, and 23 months following ticagrelor.
The primary endpoint of the study was all-cause mortality and Q-wave myocardial infarction.
This was a negative trial, but in EuroPCR they presented a sub study of this trial and looking at complex patients and whether the primary endpoint was different in the complex versus non-complex group.
So how do we define complex PCI? They define this as a multivessel disease, PCI requiring three or more stents, bifurcations with two or more stents, stenting over 60 mm of length, and so forth.
And interestingly, what they found [was] that the patients randomised to 1 month DAT [followed by] 23 months ticagrelor, had a marked reduction, by about 36%, in the primary end point of non-Q-wave MI and all-cause mortality.
And this was also quite interesting in that this was not associated with an increased risk of bleeding. There was no difference in bleeding between the complex and the non-complex arm. And there was also a dose response curve in that the magnitude of benefits associated with ticagrelor was greater the more complex features were there.
Why is this important? I think it's important because again, it comes back to the personalisation of our approach in PCI. And it seems that perhaps using a more potent single antiplatelet therapy is more efficacious and has better outcomes in more complex patients, which makes sense in that the more complex they are, the greater the benefit.
I guess the negative parts of the trial, it was a post hoc analysis of a negative randomised control trial. And again, that's problematic. So I think it's important in terms of hypothesis generation, should it or will it change practice? Probably not.
So I think in summary, EuroPCR has been great meeting. Social media has been very active. A number of studies have been presented and a number of consensus statements have been presented that will really make us think about how we practise interventional cardiology and push more towards a personalised approach in interventional cardiology. So I thank you for joining us, and perhaps you could add in the comments section what you think are the highlights of EuroPC.
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Cite this: Mamas A. Mamas. EuroPCR 2019 Practice-Changing Highlights – Part 2 - Medscape - May 29, 2019.