Randomized trial of primary PCI with or without routine manual thrombectomy

Abstract

Background: During primary percutaneous coronary intervention (PCI), manual thrombectomy may reduce distal embolization and thus improve microvascular perfusion. Small trials have suggested that thrombectomy improves surrogate and clinical outcomes, but a larger trial has reported conflicting results.

Methods: We randomly assigned 10,732 patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary PCI to a strategy of routine upfront manual thrombectomy versus PCI alone. The primary outcome was a composite of death from cardiovascular causes, recurrent myocardial infarction, cardiogenic shock, or New York Heart Association (NYHA) class IV heart failure within 180 days. The key safety outcome was stroke within 30 days.

Results: The primary outcome occurred in 347 of 5033 patients (6.9%) in the thrombectomy group versus 351 of 5030 patients (7.0%) in the PCI-alone group (hazard ratio in the thrombectomy group, 0.99; 95% confidence interval [CI], 0.85 to 1.15; P=0.86). The rates of cardiovascular death (3.1% with thrombectomy vs. 3.5% with PCI alone; hazard ratio, 0.90; 95% CI, 0.73 to 1.12; P=0.34) and the primary outcome plus stent thrombosis or target-vessel revascularization (9.9% vs. 9.8%; hazard ratio, 1.00; 95% CI, 0.89 to 1.14; P=0.95) were also similar. Stroke within 30 days occurred in 33 patients (0.7%) in the thrombectomy group versus 16 patients (0.3%) in the PCI-alone group (hazard ratio, 2.06; 95% CI, 1.13 to 3.75; P=0.02).

Conclusions: In patients with STEMI who were undergoing primary PCI, routine manual thrombectomy, as compared with PCI alone, did not reduce the risk of cardiovascular death, recurrent myocardial infarction, cardiogenic shock, or NYHA class IV heart failure within 180 days but was associated with an increased rate of stroke within 30 days. (Funded by Medtronic and the Canadian Institutes of Health Research; TOTAL ClinicalTrials.gov number, NCT01149044.).

Figure 1. Kaplan–Meier Estimates for the Primary Outcome and Stroke at 180 Days

Shown are the cumulative hazard rates of the primary outcome (death from cardiovascular causes, recurrent myocardial infarction, cardiogenic shock, or New York Heart Association class IV heart failure) (Panel A) and stroke (Panel B) in the thrombectomy group and the percutaneous coronary intervention (PCI)–alone group within 180 days after the procedure. In each panel, the inset shows a more detailed view of the same data up to a probability of 0.08 in Panel A and 0.020 in Panel B.

Figure 2. Forest Plot of the Primary Outcome in Prespecified Subgroups

With the use of the Thrombolysis in Myocardial Infarction (TIMI) grading system, patients were categorized according whether the largest dimension of the thrombus was 0.5 to 2.0 times the diameter of the vessel (grade 3) or more than 2.0 times the diameter (grade 4). TIMI flow was graded on a scale of 0 to 3, with a higher grade indicating better flow. The size of the squares is proportional to the number of patients.