PARIS, France—Mechanical thrombectomy added to direct stenting in patients experiencing ST-segment elevation myocardial infarction (STEMI) improves 1-year clinical outcomes over stenting alone, according to updated trial data presented Tuesday, May 25 at EuroPCR 2010.

The finding builds upon positive 6-month data from the JETSTENT study released earlier this year at the ACC/i2 Summit in Atlanta, GA, bolstering the case for routine thrombectomy use in STEMI patients with evidence of thrombus, according to investigator David Antoniucci, MD, of Careggi Hospital (Florence, Italy).

Selective Use of Thrombectomy Pays Off

For JETSTENT, researchers looked at STEMI patients admitted within 12 hours of symptom onset, excluding those who had received fibrinolysis, experienced a stroke within the previous 30 days or surgery within the previous 6 weeks, or had been previously stented in the infarct-related artery. After angiography and guidewire placement, those with thrombus grades 3 to 5 were randomized to undergo direct stenting alone (n = 245) or stenting plus mechanical thrombectomy using AngioJet (n = 256; Medrad Interventional/Possis, Minneapolis, MN).

Baseline characteristics were similar between groups, and abciximab was given to the majority (97%-98%) of patients. Notably, 2.7% of thrombectomy patients and 5.3% of stenting patients had cardiogenic shock, although the difference was not significant.

The co-primary endpoint of ST-segment resolution ≥ 50% at 30 minutes occurred more frequently with thrombectomy (85.8%) than with stenting (78.8%; P = 0.043). But 1-month infarct size, the study’s other co-primary endpoint, was equivalent between the thrombectomy and stenting groups (11.8% and 12.7%; P = 0.398). Compared with stenting alone, thrombectomy significantly reduced MACCE (composite of death, MI, TVR, and stroke) at 1 month (3.1% vs. 6.9%; P = 0.050) and at 6 months (12.0% vs. 20.7%; P = 0.012). Six-month outcomes for death, MI, and TVR numerically favored thrombectomy but the differences were not significant, whereas stroke was nearly equal between the 2 treatments.

One-Year Update

The initial differences in clinical outcomes between thrombectomy and stenting alone were maintained from 6 months to 1 year, with the greatest magnitude of benefit obtained in death and MI rates. Stroke rates remained equivalent between the 2 arms (table 1).

Table 1. Clinical Outcomes at 1 Year

^a P = 0.040

In addition, Kaplan-Meier curves showed significantly higher event-free survival at 420 days after thrombectomy compared with stenting alone (85.2 ± 2.3% vs. 75.0 ± 3.1%; P = 0.009).

Although JETSTENT's primary efficacy endpoints were not met, Dr. Antoniucci concluded that clinical outcomes from the study continue to support the use of thrombectomy before infarct artery stenting in patients with AMI and evidence of coronary thrombus. He commented at a press conference that the trial surpasses previous evaluations of thrombectomy, because JETSTENT “for the first time compared thrombectomy [performed alongside] the best standard of therapy, meaning direct stenting in all patients without pre or post dilation” and adjunctive use of abciximab.

Adequately Powered Trials Needed to Inform Practice

According to Goran Stankovic, MD, of the Clinical Center of Serbia (Belgrade, Serbia), JETSTENT appropriately refocuses on “the importance of thrombus burden in STEMI patients.” Furthermore, the study's observed “benefit in terms of hard clinical endpoints goes along with the TAPAS trial, which also demonstrated survival benefit at 1 year,” he added.

Dr. Stankovic praised the study's choice of infarct size and early ST-segment resolution as co-primary endpoints but pointed out that the lack of significant improvement should have been expected, “because 60% of patients included in the study had non-anterior MIs and and most of the data suggest there is little incremental reduction in infarct size in patients with these infarctions.”

Moreover, Dr. Stankovic cautioned that differences in complexity between manual aspiration and mechanical thrombectomy devices such as AngioJet should be kept in mind. He cited results from a meta-analysis showing that while aspiration curbs mortality, mechanical thrombectomy appears to increase risk (Bavry AA. Eur Heart J. 2008;29:2953-2954).

“JETSTENT was not powered for hard clinical endpoints,” and therefore, adequately powered new trials with long-term follow-up are still needed in order “to definitively say that we should be using rheolytic thrombectomy routinely in all patients with STEMI and thrombus present,” he concluded.

Disclosures:

• The study was sponsored by Medrad Interventional/Possis.
• Drs. Antoniucci and Stankovic report no relevant conflicts of interest.

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