No benefit of routine thrombus aspiration during PCI
medwireNews: Routine thrombus aspiration during percutaneous coronary intervention (PCI) for the treatment of ST-segment elevation myocardial infarction (STEMI) does not improve clinical outcomes, researchers report.
In a meta-analysis of individual patient data from three randomized trials, the researchers found that cardiovascular death at 30 days occurred in 2.4% of 9155 patients undergoing manual thrombus aspiration during PCI, compared with 2.9% of 9151 who underwent PCI alone, a nonsignificant difference (hazard ratio [HR]=0.84).
Similarly, there was no significant difference in the incidence of stroke or transient ischemic attack (TIA) at 30 days between patients undergoing thrombus aspiration versus PCI alone, at 0.8% versus 0.5% (HR=1.43), and the rates of recurrent myocardial infarction, stent thrombosis, heart failure, and target vessel revascularization were similar in the two groups.
These findings indicate that “[t]hrombus aspiration should not be used as a routine strategy in patients with STEMI,” write Sanjit Jolly (Hamilton General Hospital, Ontario, Canada) and fellow researchers in Circulation.
However, in subgroup analyses, thrombus aspiration was associated with a significant reduction in cardiovascular death, and a higher incidence of stroke or TIA, among patients with high thrombus burden (Thrombolysis In Myocardial Infarction thrombus grade ≥3 or higher).
In this patient subgroup, cardiovascular death occurred in 2.5% of patients undergoing thrombus aspiration during PCI, compared with 3.1% of those undergoing PCI alone (HR=0.80), and stroke or TIA was experienced by 0.9% and 0.5% of patients, respectively (HR=1.56). There were “no differences” in the incidence of cardiovascular death or in stroke or TIA with thrombus aspiration among patients with low thrombus burden.
“It is biologically plausible that thrombus aspiration is only beneficial in patients with moderate to high thrombus burden,” say Jolly and colleagues. Nevertheless, they concede that “the increase in stroke could counterbalance an early benefit such that the effect on all-cause mortality at 1 year was neutral.”
The limitations of current manual thrombus aspiration technology include “thrombus embolization downstream due to wire crossing (prior to aspiration), limited ability to deal with large organized thrombi, and embolization of thrombus to other vascular territories during removal of the aspiration catheter,” note the authors.
And they conclude: “Whether improved methods for thrombus aspiration could reduce the risk of stroke and enhance overall benefit is not known, and warrants testing in future trials among patients with high thrombus burden.”
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