A New Class for Thrombus Aspiration and Primary PCI for STEMI Patients
An interview with Eric Bates, MD, FACC, on the 2015 ACC/AHA/SCAI Focused Update
In Focus | How to handle non-culprit lesions in patients with ST-elevation myocardial infarction (STEMI) has been a heated topic in the last few years. Treating this high-risk group of patients who undergo percutaneous coronary intervention (PCI) can be challenging in the face of shifting guidelines that exist to help physicians in their decision-making process. In the November issue of CardioSource WorldNews, we heard from John Spertus, MD, MPH, FACC, on the ACC/AHA/SCAI Focused Update on Primary PCI for STEMI Patients. This month, Eric Bates, MD, FACC, professor of internal medicine at the University of Michigan Health System, provides his thoughts and insight into the update and what it could mean moving forward.
CSWN: There have been conflicting results about the benefits of non-culprit PCI for some time. This is an important issue, isn’t it?
Eric Bates, MD: Yes, it is. For years, this procedure was a Class III recommendation, based, I think, on early experiences many of us had: we had inadequate antiplatelet and anticoagulant therapy, and we didn’t have stents, so doing more often got us into trouble with complications in the second artery more than the first artery. So, for 25 years, the practice has been to only work on the culprit lesion and then undergo the evaluation based on ischemia-guided therapy as to whether or not to revascularize other lesions if the patient had multivessel disease. About 50% of these patients do, but there have been some observational studies over the last 10 or 12 years supporting the guidelines. But, most recently, we’ve had some randomized clinical trials that have yielded the opposite results, and reinitiated the discussion about the possibility that, with better antithrombotic therapy, stents, and other advances, it might be more efficient and even save resources to do multivessel revascularization at one setting instead of two settings.
There is “stenotic optic reflex,” as it is called, and any interventionalist who sees it wants to fix it. Was there any pushback on this with the guidelines considering it a Class III because it “could do harm”? Do you find there was more criticism or support of this recommendation?
Well, the Europeans have, in the year before, raised it to a Class IIb recommendation, and some people are enthusiastic about pursuing this new treatment strategy. It is important to recognize that the European guidelines actually give a rather cautious green light to this. The treatment is intended to be in selected patients. It is not intended for patients with complex lesions or patients with 50% stenosis, in my opinion, or total occlusions. The patients have to have an uncomplicated infarct artery PCI and not have any risk for volume overload or contrast nephropathy, which could harm them and is actually associated with death in the hospital. So the strategy has been demonstrated in the current era to be safe. We’re still arguing about efficacy, and we still haven’t proven whether it actually does decrease the risk of death or MI.
So what is the new guideline update in terms of what to do for these patients?
The guideline sunsets the Class III recommendation that you should not do the procedure, and it matches the European guideline recommendation that the procedure is a IIb recommendation in selected patients. If a physician wants to do it, the artery still has to be one that would pass standards for elective PCI—probably a really tight stenosis, not an intermediate stenosis, in a really stable patient, because the reason to do it is to be more efficient. Say, if somebody comes in on a Friday, and there is going to be a 2-day hospital stay instead of a 4- or 5-day hospital stay, that might push a physician toward doing it.
But I think we need to be really careful not to embrace this new strategy too aggressively and cause patients harm, because most people in the U.S. still pursue the deferred strategy, which has been standard of care for a long time. A physician should wait a couple days and do the other artery when he or she knows the patient better, maybe then have more information on the appropriateness of doing PCI. The recommendation is in selected cases, in lesions that meet appropriate indications for PCI; you can have a go at it as long as you think that is the best treatment strategy for that patient.
And there are current investigations, such as the COMPLETE trial, that, hopefully, will give us a better answer on the question of efficacy, is that right?
This is a hot area of investigation, as you mentioned. In fact, there have been 17 meta analyses on this subject, and there are now 10 randomized trials looking at different combinations of timing. The study you referred to, the COMPLETE trial, which is a 3,900-patient study coordinated out of McMaster University in Ontario, that is going to compare culprit-only PCI versus staged PCI, but it will not answer the question of whether multivessel revascularization can be done in one setting or two settings. But that trial will be the data source to make a recommendation on staged PCI, which we do not have at the present time.
Now, there is a second topic—thrombus aspiration—that is addressed in the updated guidelines.
Yes, this is another very hot area in this field and the reason why the update is being put out before a new guideline is completely rewritten. As you remember, a few years ago, the TAPAS study, a single-center study of over 1,000 patients, showed EKG benefit and even some mortality benefit with thrombus aspiration, which is a fairly simple procedure to perform. Subsequently, there have been two trials showing no difference in infarct size. And then we have two very large, multicenter trials (one from Sweden and one from McMaster) showing absolutely no benefit on any endpoint with thrombus aspiration. So, in the prior guideline, thrombus aspiration was given a Class IIa indication, meaning you should think about doing it, and in the present guideline it is now a Class III indication for routine thrombus aspiration.
We really don’t have enough information to comment on the benefit of selective thrombus aspiration, which is still clinically done, but the Class III recommendation is based partly on no clear efficacy and the TOTAL trial from Canada that showed a signal of harm with an increase in stroke. No benefit is one problem. Harm is another problem, so it is no longer recommended in our guidelines or in the European guidelines as a routine strategy.
We’ve talked with Sanjit S. Jolly, MD, FACC, an investigator in that trial and the last time we spoke, there seemed to be great buildup about the TOTAL trial—this was going to be the trial that answered the question, but there was some let-down.
The main problem is that we’re getting there too late, so I’m not surprised there’s no evidence for myocardial salvage. But I think the bigger problem is the catheters we use don’t have a big enough hole to suck the clot out, and we simply aren’t getting adequate thrombus aspiration to test the hypothesis, which intuitively makes a lot of sense and is quite attractive.
Clinical Topics: Invasive Cardiovascular Angiography and Intervention
Keywords: Decision Making, Internal Medicine, Myocardial Infarction, Percutaneous Coronary Intervention, Problem Solving
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