Routine aspiration thrombectomy is associated with increased stroke rates during primary percutaneous coronary intervention for myocardial infarction

Background: Recent studies have suggested that the routine use of aspiration thrombectomy catheters during primary percutaneous coronary intervention (PCI) do not result in improved mortality and may be associated with an increased stroke rate. This study sought to investigate this hypothesis. Methods: This was an observational study analysing data from a prospective database of 6366 patients undergoing primary PCI between August 2003 and May 2015 at a UK cardiac centre. Patients' details were collected from the hospital electronic database. Primary outcome was thirty-day stroke rates. Results: 3989 (62.7%) patients underwent PCI alone and 2,377 (37.3%) patients underwent PCI with adjuctive thrombus aspiration. PCI alone group had an older demographic (63 (+/- 14) years vs 60.7 (+/- 14)), a lower proportion of male participants 75% vs 79% (P=0.001) and cardiovascular risk factors such as hypertension 22.4% vs 25.3% (P=0.007), hypercholesterolemia 18.5% vs 22.6% (P<0.0001) and a history of smoking 33.5% vs 44.3% (P<0.0001). Thrombus aspiration was associated with a higher 30-day stroke rate [16 (0.7%) vs 11 (0.3%) (HR 2.51; 95% CI 1.03-6.08, P 0.03). Multivariate analysis suggested that this increased risk of stroke was maintained following adjustment for confounders (HR: 1.86; 95% CI 1.02-4.38). There was 379 deaths of which 114 (4.8%) were in the thrombus aspiration cohort vs 265 (6.6%) in PCI only cohort over the follow-up period (60 months). This resulted in a significantly lower rate of all-cause-mortality HR 0.70 (95% CI 0.52-0.94; P 0.02). There was no statistically significant difference in observed myocardial infarction rates HR 0.76 (95% CI 0.47-1.23; P 0.27) and the rates of unscheduled revascularisations HR 0.70 (95% CI 0.43-1.13; P 0.14) between the two groups. Conclusions: Our data series of STEMI patients, suggest that routine thrombus aspiration during primary PCI is associated with a significantly higher stroke, rate however, thrombus aspiration reduced mortality rate. This is consistent with current guidelines which don't recommend the routine use of thrombus aspiration for primary PCI. A possible mortality reduction in patients with high thrombus grades was seen which may warrant further study.