Toru Geshi

Acarbose treatments improve arterial stiffness in patients with type 2 diabetes mellitus.

Aims/Introduction:  Although the improvement of postprandial hyperglycemia by an alpha‐glucosidase inhibitor (α‐GI) has been associated with a risk reduction of cardiovascular events, the relationship between postprandial hyperglycemia and arterial stiffness has not been well understood. We therefore examined whether ameliorating the postprandial state by α‐GI leads to an improvement in arterial stiffness.

Beneficial effects of statin treatment on coronary microvascular dysfunction and left ventricular remodeling in patients with acute myocardial infarction

BACKGROUND Statin treatment has been shown to improve coronary endothelial function, irrespective of lipid-lowering effects. This studys aim was to elucidate the effects of statin treatment on coronary microvascular dysfunction and left ventricular remodeling in acute myocardial infarction (AMI) patients. METHODS Thirty-five patients undergoing successful reperfusion following AMI were assigned to a statin-treated (Group S, 16) or a non-statin-treated (Group NS, 19) group, according to fasting serum low-density lipoprotein-cholesterol. (13)N-ammonia positron emission tomography was performed to assess myocardial flow reserve (MFR) in the infarct area. RESULTS Infarct sizes and lipid profiles during the chronic period were similar between the two groups. At 2 weeks after AMI onset, mean MFR in the infarct area was significantly higher in Group S than in Group NS (2.34 ± 0.63 vs. 1.91 ± 0.43, p=0.0214). At 6 months post-AMI, Group S had a smaller left-ventricular end-diastolic volume index (69.4 ± 11.7 mL/m(2) vs. 88.5 ± 32.5 mL/m(2), p=0.0328) and higher left-ventricular ejection fraction (67.7 ± 9.2% vs. 59.2 ± 13.3%, p=0.0394) than Group NS. Serum asymmetric dimethylarginine was significantly increased in Group NS at 1 month post-AMI (0.43 ± 0.12 μmol/L (baseline) vs. 0.52 ± 0.14 μmol/L, p=0.0186), but unchanged in Group S. CONCLUSIONS Statin treatment appears to beneficially attenuate left ventricular remodeling after AMI, which may be associated with restoring coronary endothelial function via endogenous nitric oxide.

Relationship between microcirculatory dysfunction and resolution of ST-segment elevation in the early phase after primary angioplasty in patients with ST-segment elevation myocardial infarction.

BACKGROUNDS AND OBJECTIVES The aim of this study was to evaluate relationships between the degree of resolution of the ST-segment elevation (ST segment resolution; STR) and the extent of microcirculatory dysfunction in infarct-related area (IRA) in patients with ST-segment elevation myocardial infarction (STEMI) using (13)N-ammonia positron emission tomography (N-PET). METHODS The subjects comprised 33 patients with STEMI who underwent successful reperfusion. Serial 12-lead electrocardiography (ECG) was performed at the baseline and at 100 min after reperfusion to calculate STR. The myocardial flow reserve (MFR) was assessed quantitatively using N-PET at 2 weeks after the onset. The summed defect score (SDS) of (99m)Tc-tetrofosmin myocardial perfusion imaging was used as an index of the severity of myocardial infarction. To assess the extent of post-infarct left ventricular remodeling, the changes in the LVEDVI (ΔEDVI) were also calculated. RESULTS A significant correlation of the STR to the MFR in IRA (r = 0.68, p < 0.0001) was observed. A significant correlation was also identified between the SDS and the baseline sum ST-segment elevation (r = 0.65, p < 0.0001), while no correlation was observed between the SDS and the STR. Furthermore, a significant inverse correlation of the STR with the ΔEDVI was also recognized (r = -0.58, p < 0.01). CONCLUSIONS These data indicate that STR after successful reperfusion in STEMI is closely related to the extent of microcirculatory disturbance; in other words, incomplete STR may be a marker of persistent microcirculatory dysfunction after reperfusion therapy.