Long Term Clinical Efficacy of Thrombectomy Devices in Acute ST Elevation Myocardial Infarction

Background: Available data from randomized trials on thrombectomy in patients with ST-elevation myocardial infarction have shown favourable trends on myocardial reperfusion. However, only few data are available on the impact of thrombectomy on long term clinical outcome.The first trials on thrombectomy had a too small sample size and a too short follow-up to reliably assess the presence of a clinical benefit.

Only one, recently published, monocentric, randomized trial conducted on 1071 patients with STEMI, the TAPAS study, showed an advantage of thrombus-aspiration use in terms of mortality at one year follow-up.

To extend the investigation on this issue to a larger population, we have designed a pooled analysis of the individual patient data of prospective randomized trials comparing standard PCI with or without thrombectomy to evaluate the impact of thrombectomy use on long term clinical outcome.

Methods: After a thorough database search, all 15 principal investigators of 17 randomized trials comparing thrombectomy with standard PCI in patients with STEMI were contacted. All 10 principal investigators authoring 11 randomized trials who agreed to participate the study have been asked to complete a structured database including a series of key baseline clinical and angiographic data (sex, age, diabetes, rescue PCI, usage of IIb/IIIa-inhibitors, infarct related artery (LAD or LCX or RCA), multivessel disease, base-line TIMI flow 0 or 1 (yes or no), time from symptoms to balloon/cath-lab, thrombectomy device used (name of the device, for example Export catheter),device efficacy (device able to reach and treat the culprit lesion)) and also to update the clinical follow-up of each patient enrolled in the corresponding trial at one year or more.

Actually we have closed the data collection and we have the requested data with the updated clinical follow-up data of 11 randomized studies (REMEDIA trial, PIHRATE trial, X-AMINE ST trial, De Luca et al. trial, Noel et al. trial, EXPIRA trial, VAMPIRE trial, TAPAS trial, Kaltoft et al. trial, DEAR-MI trial, Antoniucci et al. trial).

The primary end point of this pooled analysis is the comparison of survival between patients randomized to PCI with thrombectomy or PCI without thrombectomy. The secondary end-points are survival free from myocardial infarction (MI), target lesion revascularization (TLR), major adverse coronary events (MACE: death + MI + TLR) and death + MI between patients randomized to PCI with thrombectomy or PCI without thrombectomy.

A pre-defined subgroup analysis is planned considering the following variables: diabetes, rescue PCI, IIb/IIIa-inhibitors use, time-to-reperfusion, infarct related artery, pre-PCI TIMI flow and type of thrombectomy device used.

Implications: This study will be able to provide useful data about the impact of the reported improved myocardial perfusion associated with thrombectomy on the long-term clinical outcome in patients with STEMI.

Inclusion criteria

for selected studies who entered this pooled analysis were:

• Comparison of PCI with Thrombectomy with Standard PCI in patients with STEMI
• Randomized treatment allocation

Exclusion criteria

was:

• Equivocal treatment allocation process

About the clinical and angiographic inclusion and exclusion criteria they were different for each single randomized trial that entered this pooled analysis.