The Evaluation of blood pressure treatment stratified according to Central Aortic Systolic Pressure (CASP) in Young Hypertensive Patients - The TREAT CASP study

高血压（BP）是心脏病和中风的主要原因，也是初级保健中最常见的慢性疾病。在英国，约25%的成年人和50%的65岁以上的老年人患有高血压。NICE指南建议在血压超过160/100mmHg（称为II期高血压）时进行治疗。NICE还建议对有证据表明BP损害的患者、糖尿病和/或心血管疾病（CVD）患者或风险较高的患者进行降压治疗（140-159/90-99mmHg，即I期高血压）。然而，对于I期高血压的年轻人（40岁及以下）的治疗方法尚不确定，因为；1)年轻人很少被纳入临床试验，2)不太可能发展为心血管疾病，3)风险计算方法不适用于这一较年轻的年龄组。NICE已将这一超过100万的年轻人群体确定为研究的重点，以更好地确定谁将从治疗中受益。常规的血压测量是用袖带包裹在手臂上，假设手臂上测量的压力准确地反映了靠近心脏和重要器官的动脉（主动脉）的压力。我们发明了一种简单，无创的方法来测量靠近心脏的主动脉的压力。这种压力被称为“中央主动脉收缩压”或CASP。重要的是，我们已经表明，手臂上的压力可能不是CASP的准确测量，特别是在年轻人中。此外，与手臂测量的血压相比，CASP可以更好地预测心脏压力，并可能更好地预测中风和心血管疾病。我们的研究将在伦敦大学学院血管生理学单元进行，招募患有I期高血压的年轻男性（18-40岁）。我们假设CASP低的男性（尽管手臂血压高）实际上血压正常，没有证据表明心脏紧张，不需要治疗。相反，那些高CASP值的患者会有心脏和动脉紧张的早期证据，并将从治疗中受益。我们将使用核磁共振成像来灵敏地测量心脏和动脉的结构。我们将比较高CASP的男性，治疗1年降低血压与不治疗的效果，看看降低CASP是否能改善早期心脏和动脉损伤。我们的研究没有伦理问题，因为参与研究的人通常不会接受治疗。由于我们在开发测量CASP的新方法方面的经验，我们在大型临床试验和敏感的MRI测量方面的经验，我们在开展这项研究方面处于有利地位。我们的研究费用减少了，因为我们可以使用我们的研究技术，包括我们的研究MRI扫描仪。所要求的资源用于资助工作人员、临床试验和消耗品。我们的研究结果可能为更好地对早期高血压患者进行分层提供了强有力的证据，这些患者将从治疗中获益最多，同时也避免了那些没有获益的人进行长期治疗。

High blood pressure (BP) is a leading cause of heart disease and strokes and the commonest chronic condition treated in primary care. In the UK, ~25% of all adults and 50% aged over 65yrs have high BP. NICE guidance recommends treatment when BP exceeds 160/100mmHg (called stage II hypertension). NICE also recommends treatment of lower pressures (140-159/90-99mmHg, i.e. stage I hypertension) in those with evidence of damage due to BP, those with diabetes and/or cardiovascular disease (CVD) or those calculated to be at higher risk. However, there is uncertainty what to do about treatment of younger people (aged 40yrs and under) with stage I hypertension because; i) younger people have rarely been included in clinical trials, ii) are unlikely to have developed CVD and iii) risk calculators do not apply to this younger age group. NICE has identified this group of over 1 million younger people as a key priority for research to better identify who would benefit from treatment. BP is routinely measured with a cuff wrapped around the arm and the assumption is made that pressure measured in the arm accurately reflects the pressure in the artery (aorta) close to the heart and the vital organs. We have developed a simple, non-invasive method to measure pressure in the aorta, next to the heart. This pressure is termed "central aortic systolic pressure" or CASP. Importantly, we have shown that pressure in the arm may not be an accurate measure of CASP, especially in younger people. Moreover, CASP is a better predictor of stress on the heart and may better predict stroke and CVD compared to BP measured in the arm. Our study will take place at the UCL vascular physiology unit and will recruit young men (aged 18-40 years) with stage I hypertension. We hypothesise that men with a low CASP (despite a high BP in the arm) actually have a normal BP, with no evidence of strain on the heart and do not need treatment. In contrast, those with a high CASP value will have early evidence of strain on the heart and arteries and will benefit from treatment. We will use MRI to sensitively measure the structure of the heart and the arteries. We will compare in men with high CASP, the effects of treatment for 1 year to lower BP versus no treatment, to see whether lowering CASP improves early heart and artery damage. Our study has no ethical issues as people recruited into the study would not normally receive treatment. We are well placed to conduct this study because of our experience in developing novel ways of measuring CASP, our experience in large clinical trials and in sensitive MRI measurements. The cost of our study is curtailed because of access to our research technology, including our research MRI scanner. Resources requested are to fund staff, clinical tests and consumables. Findings from our study may provide compelling evidence for a better way to stratify younger people with early hypertension who would benefit most from treatment and also avoid long-term treatment of those who would get no benefit.