ESC Congress: TASTE trial — Thrombus aspiration for acute myocardial infarction does not reduce mortality; in commentary, clinicians asked to wait for TOTAL trial

September 2, 2014 — Thrombus aspiration for acute myocardial infarction (AMI) does not reduce mortality or other clinical endpoints long term, according to the awaited one-year follow-up results from the Thrombus Aspiration in ST- Elevation myocardial infarction in Scandinavia (TASTE) trial. The findings were presented at ESC Congress today by Dr Bo Lagerqvist from Sweden.

Dr Lagerqvist said: "The results of the one-year follow-up of the TASTE trial challenge the current practice of blood clot aspiration after a heart attack."

TASTE was a multicentre, prospective, randomised, controlled open-label trial that enrolled 7 244 patients from Sweden, Denmark and Iceland who had a diagnosis of ST-elevation myocardial infarction (STEMI). Half of the patients were assigned to balloon treatment only (known as percutaneous coronary intervention, or PCI) and the other half had their blood clot aspirated before PCI.

As previously reported from the TASTE trial, the death rate when the patients were followed 30 days after treatment was not lower after clot aspiration. Today the investigators report the results after patients have been followed for one year.

The results presented today are consistent with the previous report. After one year the death rate was not statistically different between the two treatment groups (5.3% after clot aspiration and 5.6% after PCI alone). Similarly, there was no difference between the two groups regarding other endpoints including the risk of new heart attack, stroke and complications related to the treatment. Even high risk groups such as smokers, patients with diabetes or patients with large clots had similar results with either approach.

Dr Lagerqvist said: "Our findings do not support a role for this clot aspiration as a routine additional treatment in heart attacks."

He added: "Current ESC guidelines on treatment of patients with STEMI recommend that thrombus aspiration should be considered (1) and most opinion leaders advocate its use. Since the TAPAS trial suggested a mortality benefit after one year (2) thrombus aspiration has gained enormous popularity. The therapy is so popular among interventional cardiologists because it intuitively feels beneficial to aspirate the clot that closes the artery."

Dr Lagerqvist continued: "The TASTE trial is the first large-scale randomised trial of thrombus aspiration for STEMI to be large enough to reveal meaningful findings on mortality and morbidity. It enrolled more patients than all previous randomised trials of this procedure combined and included a much broader range of patients in order to make the results relevant to everyday clinical practice."

The study's unique Registry-Based Randomised Clinical Trial (RRCT) protocol used national registries as on-line platforms for randomisation, case record forms and follow-up, making the trial economically and administratively feasible.

Study chair Professor Stefan James (Sweden) said: "TASTE is the first trial ever to use the registry-based trial concept. This concept enabled enrollment of more than 80% of all eligible patients nationwide with complete control of the non-enrolled patients and unlimited duration of follow-up at a very low cost."

Trial commentary from Dr. Sanjit Jolly: Dr. Jolly is the assistant professor of medicine at McMaster University in Hamilton, ON and a principal investigator of the TOTAL trial. His disclosures include commercial interests by way of grant support from Medtronic.

“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 judgement 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.”