Impaired Endothelium-dependent Vasodilatation In Essential Hypertension And The Effect Of Carvedilol

Background: essential hypertension(EH) is a common disease in old and elderly people. The main risk in EH is arteriosclerosis and its complications in heart, brain and kidney. Recent years, it has demonstrated that the endothelium and its dysfunction in arteries has played an important role in the appearance and development of EH and its complications. For this reason , the ACC2003 annual meeting initiate the "vascular-hypertension-cardiovascular event" track to a new spotlight session to illustrated the importance of endothelial function . It has become a common idea at large doctors that "endothelium-hypertension-cardiovascular risk" chain is the most probably track for the cardiovascular diseases. Carvedilol is a new -block drug. It can be able to block the receptors as well as to resist oxidation. It has been prescribed to EH and heart failure widely. But it has not been proved that whether there is a certain benefit to the endothelial dysfunction in EH. The endothelial function on EH and the treatment of Carvedilol on it is required to study further . Method: there are 54 cases of EH diagnosis according to 1999 Chinese guidelines of prevention and treatment hypertension. And 2 groups were divided based on the guidelines with the target damage and complications in the heart and brain and kidney as well as cardiovascular risk . 32 cases were divided as low risk group which the cardiovascular risk is low or middle and 22 cases as high risk group which the risk is high or very high . And there are 30 cases as contrasted group which have normal blood pressure. There are no significant differences in the age and sex among three groups. Detection the flow-mediated vasodilatation(FMD) in right brachial artery by ultrasound in 3 groups were approached: the inner diameter of artery(Dd), velocity of flow(Q) ,vessel resistance (R), cross-sectional compliance(CC) and distensibility coefficient(DC) of the brachial artery in rest as well as which in FMD that is criticized by calculation the increased artery diameter(D%) andflow(Q%) and vessel resistance (R) .Examination the endothelin(ET-l) and Von Willibrand factor(vWF) in fast serum were obtained. The endothelial function were criticized based on above data. Then the EH patients were prescribed Amlodipine 5mg daily or combined Amlodipine 5mg/d plus Carvedilol 12.5mg/d randomly. The endothelium function above were examined repeatedly after 12 weeks long separated treatment.Result 1. There are no significant difference of artery inner diameter(Dd) ,flow(Q) and vessel resistance (R) in the rest among three groups. 2. While FMD, the increased diameter(D%) in the high risk group is lower than that in the contrasted one(6.6 4.1% vs 12.1 4.4%;P<0.01);and the increased flow(Q%) is lower than the contrasted (88 46% vs 246 88%;P<0.01);the vessel resistance (R) is higher in high risk group than that in contrasted(0.081 vs 0.045;P<0.01). 3. The increased diameter by FMD in low risk group is somehow lower than that in contrasted (10.2 卤4.5% vs 12.1 4.4%), but there is no significant difference (.P>0.05).The increased flow (Q%) in low risk group is less than that in contrasted (156 86% vs 246 88%;P<0.05). The artery resistance is certain elevated in low risk group than that in contrasted (0.077 vs 0.045;P<0.01).4. The laboratory examination of ET-1 and vWF in three group have shown that it is similar in low risk group and the contrast group(P>0.05), but it is elevated in high risk group than that in contrasted(,P<0.05). It means that the endothelial function of brachial artery in EH is seriously impaired in high risk group, but not occurred obviously in low risk group. 5. After twelve weeks treatment with Amlodipine 5 milligram diary alone or Amlodipine 5 milligram plus Carvedilol 12.5 milligram combined randomly, the data above, of endothelial function have been examined again. There are 51 cases have been examined by ultrasound. There are 29 cases prescribed Amlodipine solely and 22 cases combined with Carvedilol. Both the blood pressure are controlled well after 12 w...