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

Background-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. Methods and Results-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 flows reserve, myocardial blush grade. and myocardial dye intensitv. In STEML the surn of* ST elevation was sionificantIv, lower in X-sizer-treated patients immediately after (2.78 +/- 3.05 versus 6.15 +/- 6.32 turn: 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 us the single independent predictor of ST-segment resolution >50% (OR 4.35 95% Cl, 1.13 to 16.9, P<0.04). Major adverse cardiac events after 30 days occurred in 2 patients in each group. Conclusions-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.