Targeting microvascular dysfunction in young hypertensive patients

• Main Author: Bleakley, Caroline
• Published: Queen's University Belfast 2013
• Subjects: 616.132
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.600121

Within the hypertensive population, younger individuals are particularly difficult to risk stratify, as current risk prediction algorithms perform unreliably in the young. especially in those at low or intermediate risk of an event. Consequently, there is a need to identify reliable surrogate predictors of c~rdiovascula r disease in order to enhance current risk prediction algorithms and provide a substrate for therapeutic intervention. Statins have been shown to positively influence the microvasculature beyond their lipid lowering effects, and therefore, therapeutic intervention at an earlier stage than is currently recommended may be more effective in preventing the development of macrovascular complications. In the present study, normocholesterolaemic hypertensive patients were randomized to receive 12 weeks of therapy with simvastatin 40mg followed by placebo treatment, or vice versa. Novel measures of Doppler ultrasound analysis were obtained from the carotid, central retinal (CRA), ophthalmic (OA) and brachial arteries together with flow-mediated dilatation (FMD) of the brachial conduit. A control group was used for baseline comparative purposes. Significant differences were detected between health and disease states in the di screte wavelet transform (OWT) analysis along with differences in entropy. In the brachial conduit, the DWI analysis following deflation of a sphygmomanometer cuff differed significantly between controls and cases, while the measurement of FMO itself did not return such significant differences. In the crossover study, differences were detected before and after treatment in the OWT analysis of waveforms obtained from the OA and eRA that were not apparent with any of the traditional measures. In summary, this study has demonstrated the potential application of novel methods of waveform analysis in the early detection of cardiovascular disease and perhaps even to guide therapeutic intervention. The use of statins in normocholesterolaemic hypertensive patients may produce improvements in microvascular function that are not detectable with traditional methods of Doppler ultrasound analysis.