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SAN FRANCISCO -- Aspiration thrombectomy during percutaneous coronary intervention (PCI) did not improve outcomes in patients with non-ST-segment elevation myocardial infarction (NSTEMI), a randomized trial showed.
The extent of microvascular obstruction 1 to 4 days after the procedure -- the primary endpoint -- was not significantly different between patients who had a thrombus removed with an aspiration catheter and those who did not (1.95% versus 1.40%, P=0.17), according to Holger Thiele, MD, of the University of Leipzig Heart Center in Germany.
Action Points
- Note that this study was published as an abstract and presented at a conference. These data and conclusions should be considered to be preliminary until published in a peer-reviewed journal.
And, although the trial was not powered for clinical endpoints, there was no difference in the rate of death, reinfarction, target-vessel revascularization, or new congestive heart failure through 6 months (7.3% with thrombectomy versus 10.1% with standard PCI, hazard ratio 0.72, 95% CI 0.37-1.41), he reported at the Transcatheter Cardiovascular Therapeutics meeting here.
"I think what that really suggests is with the current antiplatelet therapy, either with glycoprotein receptor blockers or other ADP antagonists, we can do the procedure very safely," , of Henry Ford Hospital in Detroit, told ľֱ. "So there really isn't very much risk of distal embolization and, therefore, removal of clot doesn't really add anything."
"It's nice for the clinicians," he added, "because it just makes the procedure a lot less complicated than [if we had] to go in and do clot extraction in every ... case."
Both European and U.S. revascularization guidelines give aspiration thrombectomy a Class IIa, level of evidence B recommendation for patients with STEMI based mainly on the results of the TAPAS trial, which showed that removal of the clot during PCI improved reperfusion and reduced mortality at both 30 days and 1 year. The more recent TASTE trial, however, showed that outcomes were not improved with the addition of aspiration thrombectomy in patients with STEMI.
The European guidance states that thrombectomy can be considered in patients with NSTEMI, although there haven't been any trials examining the question in this patient population.
To address that gap, Thiele and colleagues conducted the , which was conducted at seven German centers. The 440 patients included in the study had ischemic symptoms lasting more than 20 minutes, symptoms that last occurred in the 72 hours before randomization, cardiac troponin T or I levels above the 99th percentile, and an identifiable culprit lesion containing at least a small definite thrombus.
In the thrombectomy group, thrombus material was aspirated in 74% of patients. The rate of primary stenting was significantly higher than in the standard PCI group (61% versus 45%, P<0.01).
Nevertheless, the percentage of patients with microvascular obstruction -- as measured with cardiac MRI between days 1 and 4 -- was similar in the thrombectomy and control groups (30.8% versus 29.2%, P=0.74). The extent of obstruction did not differ either, and the lack of benefit was consistent across various subgroups.
The percentage of patients with TIMI flow 3 after PCI was 85% in both groups. And there were no difference on several secondary endpoints, including myocardial blush grade, infarct size, myocardial salvage index, and enzymatic infarct size.
Despite the negative results of TATORT-NSTEMI and TASTE, , of Detroit Medical Center, said there is still a role for aspiration thrombectomy, pointing to some hints of benefit in TASTE.
"As [clinicians], we tend to choose large thrombi in the vessels before [deciding] to perform thrombectomy, and so I think some of us are still going to use thrombectomy," she said during a press briefing.
After Thiele's presentation, , of Charles George VA Medical Center in Asheville, N.C., questioned whether the aspiration catheter is the right tool to use, saying that "it's insufficient, it's inefficient, [and] it does not remove adequate thrombus burden."
, of University Hospitals Case Medical Center in Cleveland, agreed.
"The drive really is to find a better thrombectomy device and then perhaps the results would be better," he said in a panel discussion after the presentation. "And I think that's what we probably have learned from TASTE and now [TATORT-NSTEMI]. We need more tools."
Disclosures
The trial was funded by unrestricted grants from Terumo Europe and Lilly Germany.
Thiele reported relationships with Terumo, Lilly, The Medicines Company, Maquet Cardiovascular, Teleflex Medical, AstraZeneca, Daiichi Sankyo, and Boehringer Ingelheim.
Primary Source
Transcatheter Cardiovascular Therapeutics
Source Reference: Thiele H, et al "TATORT-NSTEMI: a prospective, randomized trial of thrombus aspiration in thrombus-containing culprit lesions in non-ST-segment elevation myocardial infarction" TCT 2013.