Effectiveness of distal protection with the GuardWire Plus during primary angioplasty for acute myocardial infarction

To evaluate the effectiveness of distal protection with the GuardWire Plus during primary angioplasty in patients with acute myocardial infarction.Thirty-eight consecutive patients undergoing stent implantation with distal protection using the GuardWire Plus (DP-group) were compared with a matched control group undergoing conventional stent implantation after balloon angioplasty without distal protection (NDP-group). Microvascular circulation after revascularization was assessed by Thrombolysis in Myocardial Infarction (TIMI) flow grade, myocardial blush grade (MBG), serum creatine kinase peak release, and ST resolution. Left ventricular ejection fraction was measured by echocardiography at discharge. Follow-up quantitative coronary angiography and left ventriculography were performed 6 months after percutaneous coronary intervention. Quantitative coronary angiography data, restenosis rate, target lesion revascularization rate and follow-up left ventricular ejection fraction were also compared between the two groups.No significant differences were observed in baseline clinical and angiographic characteristics between the two groups. The TIMI flow grade 3 (DP-group 81.6% vs NDP-group 57.9%)and MBG 3 (57.9% vs 30.6%)were significantly greater in the DP-group respectively (p0.05). Post procedural ST-segment resolutionor = 50% was found in a significantly higher percentage of patients in the DP-group (68.4% vs 42.1%, p0.05). Left ventricular ejection fraction at discharge was significantly greater in the DP-group (55.5 +/- 8.5% vs 45.7 +/- 11.1%, p0.05). However, 6 months after the percutaneous coronary intervention, no significant difference was observed between the two groups. Restenosis rate and target lesion revascularization rate were similar in the two groups.Distal protection with the GuardWire Plus improved the microvascular circulation as assessed by TIMI flow grade, MBG, and ST resolution. Furthermore, left ventricular ejection fraction at discharge was improved.