TREAT CASP

Evaluation of blood pressure TREATment stratified according to Central Aortic Systolic Pressure (CASP) in young hypertensive patients: The TREAT CASP study

Blood pressure (BP) is usually measured using a cuff inflated over the upper arm. BP exceeding a threshold value is indicative of hypertension (high blood pressure). However, the decision whether to treat hypertension is based on an additional assessment of future risk of heart disease, indicated by presence of existing heart or kidney disease, evidence of damage caused by BP, prediction based on cardiovascular (CV) risk calculators. Despite this, uncertainty remains about whether to treat young people with moderately elevated BP (stage 1 hypertension; BP 140-159/90-99mmHg). This is because young people are unlikely to have developed pressure-mediated damage and because risk factor calculators have little validity in young people. This uncertainty is recognised in the UK national treatment guidelines (NICE) which currently recommend leaving these people untreated but acknowledges that simple tools to better assess which younger people with stage 1 hypertension should receive treatment are required. This study aims to address this issue by looking at whether the way in which we measure blood pressure could be refined. Usual BP measurement assumes that pressure measured in the arm is uniform throughout the body. However, we know from previous studies that there is an increase of pressure with increasing distance moving away from the heart towards the periphery (i.e. towards the arm). Importantly, this amplification varies markedly between people, particularly between young people. This means that despite having the same moderately elevated BP measured over the arm, some young people may have elevated blood pressure near their heart, whilst others may have a near normal BP near their heart. Moreover, some studies have shown that BP measured near the heart is more relevant to CV risk than BP measured over the arm. Blood pressure near the heart can now be measured routinely using a modified blood pressure monitor. We wish to test whether BP near the heart can be used to identify young people with moderately elevated BP who are at increased CV risk and who should receive treatment. 

Trial status: Completed. No longer recruiting.
Funder: NIHR Efficacy and Mechanism Evaluation
Sponsor: University College London
ISRCTN: ISRCTN09502665