Intracoronary Thrombectomy With the X-Sizer Catheter System Improves Epicardial Flow and Accelerates ST-Segment Resolution in Patients With Acute Coronary Syndrome

Abstract

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 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. 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.