BARCELONA – Routine thrombus aspiration in patients with acute ST-elevation myocardial infarction failed to produce a 1-year survival benefit over conventional care in a multicenter, randomized trial with more than 7,000 patients, negating a previously reported 1-year survival boost from thrombus aspiration in a single-center study with about 1,000 patients.
"Our recommendation is that routine thrombus aspiration not be done" in patients with ST-elevation myocardial infarction [STEMI] undergoing percutaneous coronary intervention [PCI], Dr. Bo Lagerqvist said at the annual congress of the European Society of Cardiology. A year ago, he and his associates reported no 30-day mortality benefit from routine thrombus aspiration during PCI in the same TASTE (Thrombus Aspiration in ST-Elevation Myocardial Infarction in Scandinavia) study (N. Eng. J. Med. 2013;369:1587-97).
Mitchel L. Zoler/Frontline Medical News
Dr. Bo Lagerqvist
But Dr. Lagerqvist and other experts left the door open to thrombus aspiration for cause during PCI, a niche that likely will continue to fuel interest in a technique that has soared in popularity despite its unproven benefit.
"The abundance of devices [for performing thrombus aspiration] on the market contrasts with the paucity of data" showing benefit, commented Dr. Gilles Montalescot, professor of cardiology at University Hospital La Pitié Salpêtrière in Paris.
"I don’t expect a reduction in use of thrombus aspiration despite the results," commented Dr. Carlo Di Mario, an interventional cardiologist at Royal Brompton Hospital in London. "Cardiologists use thrombus aspiration to create a larger lumen" when an infarct-related artery is blocked with a large thrombus. "The alternative it to use a balloon, which can cause embolization and which just exchanges one device for another."
TASTE randomized 7,244 acute STEMI patients undergoing PCI at 29 centers in Sweden and 1 center each in Iceland and Denmark. They averaged about 66 years of age, and 78% of patients had either full occlusion or low coronary flow through the infarct-related artery at the time of hospitalization.
One year after intervention, the rates of all-cause death, repeat STEMI, and of stent thrombosis were each identical in the patients who received thrombus aspiration and those who did not, reported Dr Lagerqvist, a cardiologist at Uppsala (Sweden) University Hospital. In addition, the absence of a benefit was consistent across several subgroups included in the analysis, which meant the researchers found no type of acute STEMI patient who clearly benefited from thrombus aspiration. Concurrent with his report at the meeting the results also appeared online (N. Engl. J. Med. 2014 [doi: 10.1056/NEJMoa1405707]).
"We saw no danger from thrombus aspiration, and it is relatively inexpensive, so it is possible to use it, but we don’t know how to identify the patients who might benefit from it, even patients with a full coronary occlusion" from thrombus, he said during a press conference. Before the TASTE results were known, roughly 50% of Swedish primary PCI cases for acute STEMI also received thrombus aspiration; today, use is "very, very low," Dr. Lagerqvist said.
Dr. Lagerqvist and others acknowledged that even more definitive data on the role of thrombus aspiration during PCI for acute STEMI will come from the TOTAL (Trial of Routine Aspiration Thrombectomy With PCI vs. PCI Alone in Patients With STEMI Undergoing Primary PCI) study, which has randomized nearly 11,000 patients and is expected to report results next year. Dr. Sanjit Jolly, an interventional cardiologist at McMaster University in Hamilton, Ont., and lead investigator of TOTAL, made this written statement about the new TASTE report:
"Thrombectomy is a one-time intervention unlike an ongoing drug therapy (i.e., ticagrelor). Therefore, the hypothesis that late events may have been more responsive to thrombectomy than early events is likely unrealistic. While TASTE excludes a 50% reduction in mortality with thrombectomy, it was not powered for realistic 20%-25% reductions in outcomes. Therefore, clinicians should reserve judgment and await the results of the largest trial examining this question, the TOTAL trial. The TOTAL trial has randomized nearly 11,000 patients to thrombectomy vs. PCI alone in STEMI and uses a composite outcome with blinded adjudication of outcomes. The TOTAL trial is powered for a 20% relative risk reduction and is expected to be presented in early 2015."
TASTE received no commercial support. Dr. Lagerqvist and Dr. Di Marco had no disclosures. Dr. Montalescot has received honoraria and research support from several companies including Medtronic, which markets a thrombectomy catheter. Dr. Jolly has received research support from Medtronic.
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