The Impact of Mitral Annular Calcification on Left Ventricular Function in Nonagenarians

BACKGROUND AND OBJECTIVES: Mitral annular calcification (MAC) is known to be associated with degenerative processes of the cardiac fibrous skeleton and cardiovascular disease mortality. However, MAC has not been evaluated in an extreme age group (patients > or =90 years of age). In this study, the clinical significance of MAC associated with aging was examined in this age group and compared with MAC associated with aging in a younger (20 to 50 years of age) group of patients. SUBJECTS AND METHODS: We assessed echocardiographic parameters in 43 nonagenarians and 51 young patients. In the nonagenarian group, patient's age was 92+/-2 years and 27% were male; in the young control group, patient's age was 36+/-9 years and 51% were male. Comprehensive M-mode and Doppler echocardiography, including tissue Doppler imaging, were performed. The frequency and severity of MAC was assessed from the leading anterior to the trailing posterior edge at its largest width for least 3 cardiac cycles. RESULTS: Echocardiography showed that the left ventricular (LV) end-diastolic dimension was larger in the young controls (p=0.007); however, the ejection fraction (EF) was lower in the nonagenarian group (p=0.001). The frequency of MAC was greater in nonagenarians {42/43 (97%)} than in controls {9/51 (17%), p<0.0001}. The maximal width of MAC was larger in nonagenarians (0.52+/-0.17 mm and 0.05+/-0.13 mm, p<0.0001). MAC was correlated with LV mass index (g/m2) (r=0.280, p=0.014) and EF (%) (r=-0.340, p=0.001). More importantly, early mitral inflow velocity/early diastolic mitral annulus velocity (E/E') was strongly correlated with MAC in non-agenarians (r= 0.683, p<0.0001). CONCLUSION: MAC may be associated with extreme age and increased LV filling pressure in nonagenarians. Further study is necessary to assess the cardiovascular mortality and structural changes related to mitral annulus calcification associated with aging.

The Protective Effects of Ascorbic Acid on the Vascular Motilities in Streptozotocin-induced Diabetic Rat / 대한흉부외과학회지

BACKGROUND: More than 70% of morbidity and mortality of diabetes mellitus is due to macrovascular complications. These complications may be associated with defect of endothelium-dependent vascular relaxation. There have been suggestions that this defect might be due to direct toxicities of oxygen-free radical. So in this study ascorbic acid was used as a dietary supplement in streptozotocin induced diabetic rats to correct this defect. MATERIAL AND METHOD: Sixty male Sprague-Dawley rats were used in this study. They were divided into control and experimental groups. Streptozotocin was injected to the 33 rats of experimental group and then divided into two the other receiving subgroups; one receiving ascorbic acid supplement(1 g/l in drinking water); and nosupplements. At 6, 9 and 12 weeks, abdominal aortic rings were obtained to make tissue preparations for evaluation of vascular smooth muscle contractility. RESULT: While control group showed good response to acetylcholine induced relaxation, diabetic group showed decreased relaxation regardless of ascorbic acid supplement at the experiments 6 weeks after streptozotocin treatment. This abnormal endothelium-dependent vascular relaxation was markedly reversed at 9 and 12 weeks into the diabetic group with ascorbic acid supplement. There were no differences in sodium nitroprusside induced relaxation responses between control and experimental groups; also, norepinephrine induced contractile responses did not show any remarkable effects. CONCLUSION: These results strongly suggest that the endothelial cells have defects in diabetic rats. Dietary supplement of ascorbic acid can reverse the defects of diabetic endothelial cells through its antioxidant effects and it may further protect against vascular disease in diabetic patients.