Outcomes from selective use of thrombectomy in patients undergoing primary percutaneous coronary intervention for ST elevation myocardial infarction: an analysis of the British Cardiovascular Intervention Society/National Institute for Cardiovascular Outcomes Research (BCIS-NICOR) registry 2006-2013

Abstract

Objectives
This study used a large national cohort to examine patterns of thrombectomy use in ST-segment elevation myocardial infarction (STEMI) and the relationship to mortality.

Background
The impact of coronary thrombectomy on mortality in STEMI has not been definitively established. Published trial data have been insufficiently powered to address this.

Methods
The U.K. national registry was used to study 98,176 patients treated with primary percutaneous coronary intervention (PCI), between January 1, 2006, and December 31, 2013. Patients were grouped on the basis of whether they received thrombectomy or not; subgroups of simple (manual aspiration) and complex (mechanical) thrombectomy were also evaluated. The primary endpoint was 30-day mortality. The principal adjusted analysis used propensity score matching (PSM). A sensitivity analysis was performed using logistic regression controlled for the propensity score.

Results
Thrombectomy use markedly increased in the United Kingdom between 2008 and 2010 but plateaued thereafter at slightly below 50% of all primary PCI cases. No significant mortality difference was seen, in adjusted analyses, between the overall thrombectomy group and the no thrombectomy group, at 30 days or 1 year (at 30 days, PSM average treatment effect [ATE] coefficient 0.0028, 95% confidence interval: -0.0048 to 0.0104; p = 0.47). Likewise, no difference was seen between the simple (manual) thrombectomy versus no thrombectomy, at either time point (at 30 days, PSM ATE coefficient 0.0007, 95% confidence interval: -0.0049 to 0.0063; p = 0.80). By contrast, the complex (mechanical) thrombectomy group demonstrated a significantly higher mortality than the no thrombectomy group at 1-year follow-up (PSM ATE coefficient 0.0434, 95% confidence interval: 0.0081 to 0.0786; p = 0.017).

Conclusions
Coronary thrombectomy was not associated with lower mortality in primary PCI for STEMI when used in our large all-comer cohort in a selective manner on the basis of physician judgment. These findings are consistent with other negative clinical outcomes in recent large randomized controlled trials studying routine manual thrombectomy in primary PCI.