ACC: No Lower Heart Risk With Thrombectomy

— An increased risk of stroke in myocardial infarction patients was an unexpected finding.

Last Updated March 18, 2015
MedicalToday

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SAN DIEGO -- Compared with percutaneous coronary intervention (PCI) alone, routine manual thrombectomy in myocardial infarction patients did not reduce cardiovascular events within 180 days, but did increase the rate of stroke within 30 days.

Thrombectomy did not reduce the risk of cardiovascular death, recurrent myocardial infarction (MI), cardiogenic shock, or New York Heart Association (NYHA) class IV heart failure in patients with ST-segment elevation (STEMI), reported , from Hamilton Health Sciences in Hamilton, Canada, and colleagues.

Action Points

  • PCI plus routine thrombectomy did not reduce major cardiovascular events in STEMI patients compared with PCI alone.
  • The rate of stroke or TIA was increased in thrombectomy patients compared with patients undergoing PCI alone.

But stroke within 1 month occurred twice as often in patients who underwent routine thrombectomy compared to PCI alone (0.7% versus 0.3%, hazard ratio 2.06, 95% CI 1.13-3.75, P=0.015).

The findings were reported at a late-breaking clinical trial session at the American College of Cardiology annual meeting and published simultaneously in the .

The stroke findings were unexpected and require confirmation in further studies, Jolly said at an ACC press conference.

"The main surprise of TOTAL was the increased risk of stroke with routine thrombectomy. Clinically, that's a very important finding," , director of interventional cardiovascular medicine at the University of Texas Medical School at Houston, told .

Patients in the thrombectomy group were significantly more likely to have a stroke or transient ischemic attack within 30 days (0.8% versus 0.4%, HR 2.21, 95% CI 1.29-3.80, P=0.003).

They were also more likely to have a stroke within 180 days (1.0% versus 0.5%, HR 2.08, 95% CI 1.29-3.35, P=0.002).

Jolly cautioned against overinterpreting the 180-day results given the small event rate.

Also, there didn't seem to be a mechanism for late strokes, added discussant , director of interventional cardiology at Piedmont Heart Institute in Atlanta.

The TOTAL is the largest trial to date evaluating thrombectomy outcomes, Kandzari told told . "It's the deal-breaker clinical study for this procedure."

The results were consistent with those of the TASTE (Thrombus Aspiration in ST-Elevation myocardial infarction in Scandinavia) trial, which found that STEMI patients who underwent thrombectomy before PCI did not have better outcomes than those who did not.

But they challenge the findings of the earlier 1,071 patient TAPAS (Thrombus Aspiration during Percutaneous coronary intervention in Acute myocardial infarction Study) trial, which suggested that manual thrombectomy could reduce cardiovascular outcomes.

Kandzari said that this trial provides the resolution to the question of catheter-based thrombectomy.

Unless there is a safety hazard, interventionalists would continue to do routine thrombectomies, Kandzari said. But based on the findings of the TOTAL and TASTE trials, there should be a more selective use of thrombectomy.

"Although the findings of TOTAL are consistent with those of the TASTE trial and together suggest that the time has arrived to prepare a requiem for routine manual thrombectomy, neither study allows us to rule out the possibility that thrombus aspiration might be beneficial in high-risk patients," , of the Catholic University of the Sacred Heart in Rome, wrote in an accompanying NEJM editorial.

The trial included 10,066 STEMI patients who were referred for primary coronary intervention within 12 hours after the onset of symptoms. Patients who had undergone previous coronary artery bypass grafting or those who had received fibrinolytic therapy were excluded.

Patients were randomly assigned to undergo thrombus aspiration followed by PCI or PCI alone (with bailout thrombectomy allowed if PCI failed). A total of 7.1% patients underwent bailout thrombectomy.

Primary outcomes were cardiovascular death, recurrent MI, cardiogenic shock, and NYHA class IV heart failure within 180 days. The composite did not differ between groups: 347 (6.9%) patients in thrombectomy group and 351 (7.0%) in PCI alone group (HR 0.99, 95% CI 0.85-1.15).

There were no statistically significant differences between groups for any primary outcomes:

  • Cardiovascular death: 157 (3.1%) patients in thrombectomy group and 174 (3.5%) in PCI-alone group (HR 0.90, 95% CI 0.73-1.12)
  • Recurrent MI: 99 (2.0%) patients in thrombectomy group and 92 (1.8%) in PCI-alone group (HR 1.07, 95% CI 0.81-1.43)
  • Cardiogenic shock: 92 (1.8%) patients in thrombectomy group and 100 (2.0%) in PCI-alone group (HR 0.92, 95% CI 0.69-1.22)
  • Class IV heart failure: 98 (1.9%) patients in thrombectomy group and 90 (1.8%) in PCI-alone group (HR 1.09, 95% CI 0.82-1.45)

The authors noted several limitations including the fact that treatment was not blinded. The trial looked at routine thrombectomy regardless of thrombus burden, so a benefit of selective thrombectomy could not be ruled out.

Finally, the bailout thrombectomy rate was 7% when PCI failed, so the effect of selective use of thrombectomy versus no thrombectomy at all was not assessed.

Disclosures

The TOTAL trial was funded the Canadian Institutes of Health Research, the Canadian Network and Centre for Trials Internationally, and Medtronic.

Jolly and co-authors disclosed relevant relationships with Boston Scientific, AstraZeneca, St. Jude Medical, Medtronic, Terumo, Pfizer, Sanofi and Servier, Amarin, Bayer, Boehringer Ingelheim, Bristol-Myers Squibb, Daiichi-Sankyo, GlaxoSmithKline, Lilly, Merck Sharp & Dohme, Novartis, Otsuka, Pfizer, Roche, Medtronic, Vivus, Janssen, Orexigen, and Regado, The Medicines Company, Eli Lilly, Abbott Vascular, Janssen, and Edwards Lifesciences.

Primary Source

New England Journal of Medicine

Jolly SS, et al "Randomized Trial of primary PCI with or without routine manual thrombectomy" New Engl J Med, March 2015; DOI: 10.1056/NEJMoa1415098.

Secondary Source

American College of Cardiology

Source Reference: Jolly SS, et al "The total trial: A randomized trial of routine aspiration thrombectomy with percutaneous coronary intervention (PCI) versus PCI alone in patients with st-elevation myocardial infarction undergoing primary PCI" ACC 2015.

Additional Source

New England Journal of Medicine

Crea F "Coronary microvascular obstruction -- A puzzle with many pieces" New Engl J Med, March 2015; DOI: 10.1056/NEJMe1501882.