Biomedical subjects
Publications and source records attributed to Hidemasa Tanaka.
This study evaluated the effects of the temporary occlusion and aspiration device GuardWire on percutaneous coronary intervention for acute myocardial infarction. This device brought about a significant reduction in the no-reflow phenomenon and improvement in ST resolution compared with conventional percutaneous coronary intervention.
OBJECTIVES: The aim of this study was to evaluate how decreased plaque volume during percutaneous coronary intervention (PCI) affects coronary flow in patients with acute myocardial infarction (AMI). BACKGROUND: Coronary flow after reperfusion therapy is a major determinant of clinical outcomes in patients with AMI. However, little is still known about the changes in coronary flow that appear after PCI in response to the decreased plaque during the procedure. METHODS: The study group comprised 60 patients with AMI who underwent pre- and post-PCI intravascular ultrasound (IVUS). Qualitative and quantitative analyses were performed on all IVUS procedures. External elastic membrane volume (EEMV), lumen volume (LV), and plaque volume (PV) were measured every 1.0 mm to include the lesion and reference segments 3.0 mm proximal and distal to the lesion. The difference between pre- and post-PCI PV was defined as the index of the decrease in plaque volume (DeltaPV). The corrected TIMI frame count (CTFC) was used to evaluate coronary flow after PCI. RESULTS: Plaque volume was decreased at post-PCI IVUS in all 60 patients. Inadequate reflow (CTFC >40) was observed in 13 patients (21.7%). The decrease in PV was significantly larger in patients with inadequate reflow than in those with reflow (49.4 +/- 18.9 vs. 31.7 +/- 15.5 mm(3), p = 0.0010). Also, DeltaPV was significantly correlated with CTFC after PCI (r = 0.415, p = 0.0012). CONCLUSIONS: The decrease in PV during PCI has a negative impact on coronary flow after PCI in patients with AMI. Embolization induced by PCI may occur in all patients with AMI.
BACKGROUND: Microvascular damage immediately after reperfusion therapy is an independent predictor of left ventricular function in patients with acute myocardial infarction (AMI). However, its recovery may vary among individuals and the relationship between convalescent stage microvasculature and late myocardial morphologic change is unclear. METHODS AND RESULTS: Patients treated with coronary angioplasty within 12 h of their first anterior AMI were enrolled in this study. Coronary flow reserve (CFR) was measured 3 weeks post AMI, in both branches of the left coronary artery: culprit (left anterior descending artery: LAD) and non-culprit (left circumflex artery: LCX). Left ventriculography was performed at 3 weeks and 6 months post AMI and compared. Seventeen patients showed abnormal CFR in the LAD (Group 1: CFR<2), whereas 20 patients showed normal CFR (Group 2: CFR >/=2). Percent changes of end-diastolic volume tended to be higher in Group 1 than in Group 2 (11.8+/-21.6% vs -1.3+/-14.4%, p=0.056), and %changes of end-systolic volume was significantly smaller in Group 2 (11.8+/-22.1% vs -8.7+/-25.1%, p<0.05). A statistically significant correlation was found between absolute and relative CFR in the LAD and %change of end-systolic volume (r=-0.58: p<0.001, and r=0.40: p<0.05, respectively). CONCLUSIONS: Microvascular function in the convalescent stage may be related to these favorable changes.