Aspirating thrombi before PCI in patients with STEMI offered no 30-day survival advantage over PCI alone, according to the results of a multicenter Swedish trial. Researchers presented their data Sept. 1 at the European Society of Cardiology Congress 2013 in Amsterdam and the results were simultaneously published in the New England Journal of Medicine.

In the TASTE (Thrombus Aspiration in ST-Elevation Myocardial Infarction in Scandinavia) trial, researchers randomized 7,244 adult STEMI patients planning to have PCI after coronary angiography. Patients were all part of the Swedish Coronary Angiography and Angioplasty Registry (SCAAR), a database with information from all coronary intervention centers in Sweden and Iceland, as well as one in Denmark.

Findings from other studies evaluating thrombus aspiration have been mixed. A 2009 trial found the procedure improved survival among STEMI patients, but “a recent meta-analysis pointed to an increased risk of stroke,” wrote the TASTE trial’s researchers, led by Ole Frobert, MD, PhD, of Orebro University Hospital in Orebro, Sweden.

In their trial, Frobert and colleagues randomly assigned participants to either undergo thrombus aspiration followed by PCI (3,621 patients) or undergo PCI alone (3,623 patients). All patients had coronary angiography and PCI and some received platelet inhibitors or anticoagulants based on provider recommendation. Some patients also received other interventions, such as nitrates and stenting.

The primary outcome measure was 30-day all-cause mortality. Other endpoints included 30-day rates of hospitalizations for another MI, stent thrombosis, certain revascularizations and combined all-cause mortality or recurrent MI.

More than 93 percent of the thrombus aspiration group underwent the procedure, and about 5 percent of the PCI alone group did as well.

By day 30, 2.8 percent of the thrombus aspiration patients died, compared with 3 percent of the PCI-only patients. There were 19 thrombus aspiration patients who were hospitalized again for another MI (0.5 percent) compared with 31 of the PCI-only group (0.9 percent).

There were no significant differences between the two groups in terms of the other outcomes.

“Coronary thrombus material triggers thrombotic, inflammatory, vasoconstrictor, and other pathways, and evacuating a portion of the thrombus and plaque material addresses only a part of the pathophysiological problem. Disrupting thrombus formation pharmacologically may be more effective,” the authors concluded.

However, Robert A. Byrne, MB, BCh, PhD, and Adnan Kastrati, MD, of the German Heart Centre in Munich, wrote in an editorial that an updated trial that assesses outcomes for 12 months could help resolve the mortality discrepancy between TASTE and earlier studies.

Until then, physicians likely will continue performing thrombus aspiration. “Many interventional cardiologists will continue to perform thrombus aspiration for now, contending that the results of the TASTE trial do no entirely exclude the possibility of a potential benefit of the procedure.”