Conference Coverage

What 2019’s top five CAD trials tell us


 

REPORTING FROM ACC SNOWMASS 2020

– A repeated theme threading through much of one prominent interventional cardiologist’s personal list of the top five coronary artery disease (CAD) trials of the past year is that aspirin is very often more trouble than it’s worth.

Dr. Malcolm R. Bell, professor of medicine and vice-chair of the dept. of cardiovascular medicine at the Mayo Clinic, Rochester, Minn. Bruce Jancin/MDedge News

Dr. Malcolm R. Bell

“For some years I’ve been concerned that the only thing that aspirin does [in patients after percutaneous coronary intervention] is increase your risk of bleeding. It doesn’t really provide any additional ischemic protection,” Malcolm R. Bell, MBBS, said at the annual Cardiovascular Conference at Snowmass sponsored by the American College of Cardiology.

“I’ll remind you that, when we go back to the early stent days, the combination of clopidogrel and aspirin was never compared in a proper trial to clopidogrel alone. We’ve just inherited this DAPT [dual-antiplatelet therapy] philosophy,” observed Dr. Bell, professor of medicine and vice chair of the department of cardiovascular medicine at the Mayo Clinic in Rochester, Minn.

Here are the key takeaway messages from his five most important randomized trials in CAD during the last year.

AUGUSTUS

For years, cardiologists have grappled with how to best manage high-cardiovascular-risk patients with atrial fibrillation who seem like they might benefit from triple-antithrombotic therapy. AUGUSTUS supplied the answer: Don’t do it. Skip the aspirin and turn instead to a P2Y12 inhibitor plus a non–vitamin K antagonist oral anticoagulant (NOAC), rather than warfarin.

“I would like you to think of triple therapy as a triple threat. That’s really what triple therapy is all about”– a three-pronged threat to patient safety, Dr. Bell commented.

In AUGUSTUS, 4,614 patients with atrial fibrillation and CAD with an acute coronary syndrome (ACS) and/or percutaneous coronary intervention (PCI) in 33 countries were placed on a P2Y12 inhibitor – most often clopidogrel – and randomized double blind to either apixaban (Eliquis) or warfarin, and further to aspirin or placebo, for 6 months of antithrombotic therapy. The strategy of a P2Y12 inhibitor and apixaban without aspirin was the clear winner, resulting in significantly less major bleeding, mortality, and hospitalizations than treatment with a P2Y12 inhibitor and warfarin, with or without aspirin. Most importantly, ischemic event rates didn’t differ between the apixaban and warfarin groups. And patients randomized to aspirin had rates of ischemic events and death or hospitalization similar to placebo-treated controls, meaning aspirin accomplished nothing (N Engl J Med. 2019 Apr 18;380[16]:1509-24).

Dr. Bell noted that a meta-analysis of AUGUSTUS and three smaller randomized trials including more than 10,000 AUGUSTUS-type patients with atrial fibrillation concluded that a treatment strategy utilizing a NOAC and a P2Y12 inhibitor resulted in less bleeding than warfarin plus DAPT, and at no cost in terms of excess ischemic events. Moreover, regimens without aspirin resulted in less intracranial and other major bleeding without any difference in major adverse cardiovascular events (JAMA Cardiol. 2019 Jun 19. doi: 10.1001/jamacardio.2019.1880).

A key message of these four trials is that a NOAC is preferable to warfarin, so much so that, in high-risk patients who are already on warfarin, it’s worth considering a switch to a NOAC.

“And we should really be avoiding DAPT,” Dr. Bell added.

How soon after an ACS and/or PCI should patients with atrial fibrillation stop taking aspirin?

“In AUGUSTUS, randomization occurred at a median of 6 days, so we know that half the patients stopped their aspirin by then. In our own practice, we’re just dropping the aspirin for the most part before the patient leaves the hospital. I think if you leave them with instructions to stop the aspirin in a week’s time or a month’s time it just leads to confusion. And we should also remember that half of the major bleeding after PCI or ACS happens in the first 30 days, so it doesn’t make a lot of sense to say that we should continue it for a month and then drop it,” according to the cardiologist.

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