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

UNLABELLED: 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. MATERIALS AND METHODS: A total of 22 patients with type 2 diabetes mellitus were treated with acarbose. Cardio-ankle vascular index (CAVI) as the arterial stiffness was measured by using a VaSera CAVI instrument before and 12 months after acarbose treatment. Serum high-sensitivity C-reactive protein (hs-CRP), pentraxin-3 (PTX3) and matrix metalloproteinase (MMP) -2, -9 were measured at the same time points. Furthermore, circulating peripheral blood mononuclear cells were examined for the frequencies of CD14 positive cells expressing membrane type-1 MMP (MT1-MMP) at the single cell level using flow cytometry. RESULTS: After acarbose treatment, postprandial glucose and glycosylated hemoglobin (HbA1c) were significantly decreased. Serum levels of hs-CRP, PTX3, MMP-2 and MMP-9 were significantly decreased. CAVI showed a significant reduction, although the changes were not significant in blood pressure and heart rate. MT1-MMP expression was significantly decreased by acarbose treatment. In multivariate analysis, improvement of blood glucose, decrease of PTX3 levels and MT1-MMP expression were independent predictors of beneficial change in CAVI. CONCLUSIONS: The present study showed that the beneficial effects of acarbose on arterial stiffness are mediated by an improvement of postprandial hyperglycemia and vascular remodeling markers. In conclusion, acarbose treatment might reduce the risk of cardiovascular diseases by altering the arterial stiffness in postprandial hyperglycemic status. (J Diabetes Invest, doi:10.1111/j.2040-1124.2010.00079.x, 2010).

[A case of bacterial aneurysm complicated by severe infectious endocarditis].

We report a case of bacterial aneurysm complicated by severe infectious endocarditis. A 34-year-old man developed idiopathic fever and general fatigue persisting for a month. He was admitted to our institution, and examinations revealed severe bacterial endocarditis with vegetation at the mitral valve and mitral incompetence. Right after admission, he suddenly developed acute cardiac infarction and cardiac arrest due to occlusion of the coronary artery by emboli from vegetation of the mitral valve. After achieving a good recovery, magnetic resonance (MR) imaging demonstrated an unruptured bacterial aneurysm at the distal branch of the left middle cerebral artery (MCA) supplying the left parietal lobe 5 days after admission, and T2* weighted images demonstrated multiple signal loss lesions, which were suspected of being thrombosed bacterial micro-aneurysms or micro-vasculitis. Although there was a risk of aneurysm rupture, we decided to proceed with mitral valve replacement by an artificial heart valve made of carbon, and repeatedly observed an unruptured bacterial aneurysm by serial MR imaging and angiography. Due to the preceding cardiac surgery, we were able to completely cure the severe infection and prevent new embolic showers. Under administration of antibiotics, the bacterial cerebral aneurysm did not increase over a period of 4 weeks, and finally the aneurysm disappeared about 6 weeks after admission. Although the timing of treatment of an unruptured bacterial aneurysm and cardiac surgery for infectious endocarditis associated with a bacterial cerebral aneurysm are controversial, we think that proceeding with cardiac surgery and observing the unruptured bacterial aneurysm by repeated MR imaging and angiography under administration of antibiotics was an appropriate strategy in this case.

Three cases of iatrogenic coronary ostial stenosis after aortic valve replacement.

BACKGROUND: Iatrogenic coronary ostial stenosis (ICOS) is a rare but potentially life-threatening complication of aortic valve replacement (AVR). This complication is usually diagnosed by angiography and treated with aortocoronary bypass surgery. CASE REPORTS: In the present 3 cases pre-operative coronary angiography confirmed normal coronary arteries and they underwent uncomplicated AVR. Coronary lesions were clinically manifest within 4 months after surgery, and repeat coronary angiography demonstrated bilateral ostial stenosis in 1 patient and left main trunk stenosis in the other 2. Two cases were detected by multidetector computed tomography (MDCT) before angiography. MDCT and Virtual Histology suggested fibrous tissue formation in the lesions. All 3 patients were successfully underwent percutaneous coronary intervention (PCI) and stenting. The post-procedure clinical course has been uneventful, except for elective stenting of a recurrent lesion in 1 asymptomatic patient. CONCLUSIONS: The incidence of ICOS after AVR is low. Noninvasive MDCT is useful for early diagnosis and PCI is a possible alternative treatment. ICOS may be caused by fibrous tissue formation, and therefore be distinct from conventional atherosclerosis.