Background Thrombus aspiration (TA) has been shown to improve Myocardial Blush Grade and ST-segment resolution in patients undergoing primary percutaneous coronary intervention (PPCI) for ST-segment elevation myocardial infarction (STEMI). However, the effect of thrombus aspiration on Thrombolysis In Myocardial Infarction (TIMI) flow grade and the survival of these patients remains uncertain.

Aim To assess the effect of thrombus aspiration on TIMI flow grade and in-hospital mortality in PPCI-treated STEMI patients Main outcome measures: Post-PPCI TIMI flow grade and in-hospital mortality.

Method Analysis of prospectively collected data of all STEMI patients undergoing primary PCI between March 2008 and June 2011 at a regional tertiary centre.

Results A total of 2567 patients (mean age 63.2±13.4 years, 70.3% male) were included in this analysis. TA was performed in 1095 patients (42.7%) (the thrombectomy group), whereas 1472 patients (57.3%) underwent PPCI without TA (the non-thrombectomy group). Post PPCI TIMI flow grade 3 was achieved in 94.6% in the thrombectomy group compared to 88.7% in the non-thrombectomy group (adjusted OR; 2.0, 95% CI 1.41 to 2.83, p=0.0001). Overall in-hospital mortality was 4.5% (n=115). In a logistic regression model adjusted for many confounders, the use of thrombus aspiration was associated with a significant reduction in in-hospital mortality (2.7% vs 5.8%, adjusted OR; 0.514, 95% CI 0.29 to 0.93, p=0.027). Other independent predictors of in-hospital mortality in this model were advanced age, total ischaemic time, admission systolic blood pressure and heart rate, pre-procedural TIMI flow, admission haemoglobin and creatinine and multi-vessel coronary artery disease.

Conclusions In this large observational study of “real world” and unselected STEMI patients, manual thrombus aspiration during PPCI was associated with a significant reduction in in-hospital mortality and an increase in the rate of post-procedural TIMI flow grade 3. These findings further confirm the benefits of thrombus aspiration in these patients.