Impact of Thrombus Aspiration on Myocardial Tissue Reperfusion and Left Ventricular Functional Recovery and Remodeling After Primary Angioplasty

Background-Failure to achieve myocardial reperfusion often occurs during percutaneous coronary intervention (PCI) in patients with myocardial infarction with ST-segment elevation. We hypothesized that manual thrombus aspiration during primary PCI would favorably influence tissue-level myocardial perfusion and left ventricular (LV) functional recovery and remodeling. Methods and Results-We prospectively randomized 111 patients with ST-segment elevation myocardial infarction to either standard or thrombus-aspiration PCI. Primary end point of the study was postprocedural incidence of ST-segment resolution >= 70%. Secondary end points included Thrombolysis in Myocardial Infarction (TIMI) myocardial perfusion grade >= 2, the combination of TIMI myocardial perfusion grade >= 2 and ST-segment resolution >= 70%, post-PCI TIMI grade 3 flow, corrected TIMI frame count, myocardial contrast echocardiography score index, the absence of persistent ST-segment deviation, and time course of wall-motion score index, LV ejection fraction, and LV volume in the 2 groups. The incidence of ST-segment resolution >= 70% was 71% and 39% in the thrombus-aspiration and standard PCI groups, respectively (odds ratio, 3.7; 95% CI, 1.7 to 8.3; P = 0.001). TIMI myocardial perfusion grade >= 2 was attained in 93% in the thrombus-aspiration group compared with 71% in the standard PCI group (P = 0.006). The percentage of patients with ST-segment resolution >= 70% and TIMI myocardial perfusion grade >= 2 was significantly greater in the thrombus-aspiration group compared with the standard PCI group (69% versus 36%, P = 0.0006). Myocardial contrast echocardiography score index was significantly higher in the thrombus-aspiration group compared with the standard PCI group (0.86 +/- 0.20 versus 0.65 +/- 0.31; P < 0.0001). A significantly greater improvement in LV ejection fraction and in wall-motion score index from baseline to 6-month follow-up was observed in the thrombus-aspiration group compared with the standard PCI group (LV ejection fraction from 48 +/- 6% to 55 +/- 6% versus 48.7 +/- 7% to 49 +/- 8%, P < 0.0001; wall-motion score index from 1.59 +/- 0.13 to 1.31 +/- 0.19 versus 1.64 +/- 0.20 to 1.51 +/- 0.26, P = 0.008). Twelve patients (11%) developed LV remodeling at 6 months, 2 (4%) in the thrombus-aspiration group and 10 (18%) in the standard PCI group (P = 0.02). Conclusions-Manual thrombus aspiration in the setting of primary PCI improves myocardial tissue-level perfusion as well as LV functional recovery and remodeling. (Circ Cardiovasc Intervent. 2009;2:376-383.)