Aspiration thrombectomy in ST-elevation myocardial infarction

The major challenge in the treatment of ST-elevation myocardial infarction (STEMI) is not only restoration of normal coronary blood flow but also microvascular perfusion. In fact, both electrocardiographic (ST segment resolution) and angiographic measures of myocardial perfusion (myocardial blush grade) have been shown to predict mortality after primary percutaneous coronary intervention (PPCI). Initial enthusiasm for manual thrombectomy arose after the apparent mortality benefit observed in the TAPAS trial (N=1,071). Meta-analyses of small trials suggest that manual thrombectomy improves epicardial and microvascular perfusion with trends towards benefit for survival. On the other hand, meta-analyses of small trials of mechanical thrombectomy show improvement in ST resolution without an effect on survival. Recently, the TASTE trial (N=7,244) showed no reduction in mortality with manual thrombectomy but trends toward reduction in rates of rehospitalisation for recurrent MI and stent thrombosis. The interpretation of TASTE should be cautious given that the trial had a much lower than expected mortality, and modest but important treatment effects cannot be excluded (20-30%). The largest trial, the ongoing TOTAL trial (N=10,700), will help determine the effect of manual thrombectomy for important clinical outcomes. A planned individual patient meta-analysis of the TOTAL and TASTE trials will have approximately 17,000 patients to examine the effect on clinical outcomes.