Intracoronary thrombectomy with the X-sizer catheter system improves epicardial flow and accelerates ST-segment resolution in patients with acute coronary syndrome: a prospective, randomized, controlled study.

Abstract

In patients with acute coronary syndrome (ACS), percutaneous coronary intervention (PCI) may cause thrombus dislodgment followed by reduced flow and impaired microcirculatory function. We prospectively compared conventional PCI to a strategy of additional pretreatment using the X-sizer thrombectomy system. Sixty-six patients (51 [77%] men; 54.9+/-9.9 years) with ACS (49 with ST-elevation infarction [STEMI]) and suspected intracoronary thrombus were randomized 1:1 to pretreatment with X-sizer and conventional PCI alone. Various aspects of epicardial flow and microvascular function were studied. Baseline data were similar in both groups. Postprocedural TIMI 3 flow was obtained in 90% of X-sizer-treated patients and in 84% of controls (NS); however, corrected TIMI frame count was lower in X-sizer- treated patients (18.3+/-10.2 versus 24.7+/-14.1; P<0.05). No significant group differences were observed in final coronary flow reserve, myocardial blush grade, and myocardial dye intensity. In STEMI, the sum of ST elevation was significantly lower in X-sizer-treated patients immediately after (2.78+/-3.05 versus 6.15+/-6.32 mm; P<0.03) and 6 hours after (2.17+/-2.31 versus 4.14+/-3.7 mm; P<0.05) intervention. ST-segment resolution >50% was observed in 83% of X-sizer-treated patients and in 52% of controls (P<0.03). Multivariate analysis identified X-sizer treatment as the single independent predictor of ST-segment resolution >50% (OR 4.35; 95% CI, 1.13 to 16.9; P<0.04). Major adverse cardiac events after 30 days occurred in 2 patients in each group. In ACS with suspected thrombus, pretreatment with the X-sizer catheter system improves epicardial flow and accelerates ST-segment resolution compared with conventional PCI alone.