BARCELONA, SPAIN ( corrected ) — For the second time in two years, a study that pitted infarct-related artery (IRA) revascularization against complete revascularization at the time of index admission has shown a dramatic reduction in MACE at 12 months.
Importantly, Dr Anthony Gershlick (University Hospitals of Leicester, UK) stressed, that reduction was not driven solely by a reduction in later PCI, but also by fewer deaths, recurrent MI, and heart failure.
"The results suggest this strategy may need to be considered by future STEMI guideline committees," said Gershlick, presenting the Complete Versus Lesion-Only Primary PCI Trial (CVLPRIT) here at the European Society of Cardiology (ESC) 2014 Congress .
As Gershlick explained during his presentation, multivessel disease is seen in approximately 30% to 40% of patients undergoing primary PCI (P-PCI) for acute MI, but meta-analyses and observational studies have produced mixed results. As reported by heartwire at last year's ESC meeting, however, the PRAMI trial was the first randomized controlled trial to show a striking benefit for complete revascularization in this setting, demonstrating a 65% reduction in MACE over a mean follow-up of 23 months with total vs culprit artery PCI at the time of the primary PCI.
CVLPRIT, which was presented to the press earlier today, randomized 146 primary PCI patients to treatment of the IRA only and 150 to "complete" revascularization that treated the culprit vessel plus any other arteries with >70% stenosis at the time of the primary PCI.
Get 'er Done
Ultimately, 139 patients received treatment of the IRA only, with seven patients crossing over to complete revascularization, while in the "complete" arm, 139 patients had all eligible vessels treated, while eight patients ended up with treatment of the culprit vessel only and an additional three received IRA treatment only plus referral for CABG.
At 12 months, a major adverse cardiac event had occurred in 31 IRA patients and in 15 complete-revascularizaton patients, a highly significant difference. Of note, deaths were more than doubled in the IRA group (six vs two), as was the incidence of all-cause mortality and heart failure, although none of these differences were statistically significant, given the low event rate.
In all, 12 patients in the IRA group and seven in the complete-revascularization group underwent another PCI within the first year. A clear difference between the two strategies emerged within the first 30 days. The benefit of complete revascularization was seen across subgroups analyzed and in both intention-to-treat and as-treated analyses.
Major Adverse Cardiac Events and Individual End Points in CVLPRIT
|Event||IRA only (%)||Complete revascularization (%)||p|
Importantly, no safety differences were seen between treatment groups, a finding highlighted in the press conference by Dr Elliott Antman (Harvard Medical School, Boston, MA), who pointed out that safety is the chief reason that guidelines currently do not recommend this approach in primary PCI.
"One thing we're going to have to understand is why there was no harm here, in contrast to what has been seen in the past," he said. For example, were patients who might not have benefited in this study simply not randomized, but channeled toward a registry instead? "We're going to look forward to Dr Gershlick's analysis of the data to understand what it was about the CVLPRIT study now that enabled these results to be so positive and without the signal of harm."
Also speaking at the press conference, Dr Steen Dalby Kristensen (Aarhus University Hospital, Skølby, Denmark), who has participated in a number of ESC guideline-writing committees, said "of course" CVLPRIT, as well as PRAMI, will be considered by future guideline groups.
"I think these trials suggest it is better to do something to the lesions than to not do anything; what is an open question is when to do it."
Current guidelines, he points out, recommend a "staged" procedure: operators deal with the urgent lesion, then schedule patients to return to the cath lab for treatment of other vessels—an approach taken by "the majority" of guideline documents, he said.
"We need to find out whether this is as good as doing it immediately, so there is still some discussion in this area, and that is also why we can't go out tomorrow and change the guidelines."
Speaking with heartwire , Gershlick stressed that nonculprit lesions in an ACS patient are "absolutely" different from >70% lesions in stable coronary artery disease. In ACS, he said, the "proinflammatory" environment clearly precipitates future events.
"Even when you look at the overall outcomes for patients with ACS, subsequent events are always higher in the non-'fatal' lesions, so maybe these non–infarct-related arteries are not as stable as we think they are. . . . Even if you compare stable vs ACS [disease], nontreated lesions do worse in people with ACS."
What About "Milder" Lesions?
The holy grail of cardiology is the ability to predict just which lesions will go on to cause events, vs lesions that will remain stable. Speaking in a separate session, Dr Gregg Stone (Columbia University, New York, NY) reviewed the advances in imaging technology that is inching closer to identifying so called "vulnerable" plaques. According to Stone, gray-scale and radiofrequency intravascular ultrasound (IVUS) can already identify plaques that will place patients at risk; other rapidly evolving imaging modalities, including optical coherence tomography (OCT) and near-infrared spectroscopy, don't have as much evidence to support their use but show tremendous promise.
"We need to stop relying on the angiogram," Stone told his audience. "Angiograms are terrible for telling you how severe a lesion actually is."
Speaking with heartwire after his presentation, Stone said, "We're certainly comfortable stenting severe lesions. If we see a diameter stenosis that's 70% or greater, we know that 70% or greater has a very high likelihood of having high plaque burden. The real question for future studies is what about the more moderate lesions, the 30% to 70% lesions? Some of those are angiographically mild but quite severe if you look with a cross-sectional imaging technique such as IVUS, and they may have very high-risk plaque constituents."
Elaborating on this point, Stone noted that despite this capability, people aren't yet using IVUS for assessing plaque components—for good reason. "We don't know what to do with it yet. I can't say, look for them and then stent them, or look for them and intensify your medical regimen. People are already on maximum medical regimens, and and we need the outcomes from randomized trials, [like the one] we've just started with PROSPECT-ABSORB ."
To heartwire , Gershlick noted that investigators specifically excluded IVUS in CVLPRIT because "we wanted it to be a pragmatic trial. But [fractional flow reserve] FFR/IVUS will be part of the next one."
An earlier version of this story inadvertently credited MACE rate numbers to the culprit-vessel only group, instead of the total-revascularization group.
Heartwire from Medscape © 2014 Medscape, LLC
Cite this: Dramatic Drop in MACE With Complete vs Culprit P-PCI - Medscape - Sep 01, 2014.