Association between Stage 1 Hypertension Defined by the 2017 ACC/AHA Hypertension Guideline and Cardiovascular Risk: A Large Cohort Study from the UK

ImportanceThe 2017 American College of Cardiology (ACC)/American Heart Association (AHA) hypertension (HTN) guideline lowered the threshold for HTN from 140/90 mmHg to 130/80 mmHg for systolic/diastolic blood pressure (SBP/DBP), resulting in a newly defined stage 1 HTN with an SBP/DBP reading of 130-139/80-89 mmHg. Few studies have assessed the impact of the redefined HTN on cardiovascular outcomes among the UK population. ObjectiveTo examine the effects of the revised ACC/AHA stage 1 HTN blood pressure parameters on the prevalence of HTN and related cardiovascular disease (CVD) risk in a large UK population. DesignAdult men and women from a national cohort study in the UK. SettingThe UK Biobank Study. ParticipantsA total of 470,625 adults (mean age 56 years) with available data on blood pressure (BP) and without a history of CVDs at baseline. Main outcome measuresIncident composite CVD outcome. MethodsProspective CVD events were analysed for survival in relation to BP measures using Cox proportional hazards regression models, adjusting for potential confounders. The associations are described by hazard ratios (HRs) and 95% confidence intervals (CIs). ResultsBy adopting the 2017 ACC/AHA HTN guideline, an additional 24.7% of the participants were classified as having ACC/AHA stage 1 HTN, which resulted in a prevalence of HTN of 75.1% at baseline. During a mean follow-up period of 8.1 years, ACC/AHA stage 1 HTN (130-139/80-89 mmHg) was associated with a significantly increased risk of CVD (HR 1.20; 95% CI 1.10-1.30) compared to the risk associated with a normal BP (<120/80 mmHg). The excess risk of CVD associated with ACC/AHA stage 1 HTN was mainly driven by myocardial infarction (HR 1.19; 95% CI 1.05-1.36) and haemorrhagic stroke (HR 1.40; 95% CI 1.08-1.81), rather than ischaemic stroke (HR 1.02; 95% CI 0.87-1.19) and CVD death (HR 1.07; 95% CI 0.90-1.26). ConclusionsThe adoption of the 2017 ACC/AHA guideline would lead to a dramatic increase in the prevalence of HTN in the UK Biobank cohort study. Evidence from the present national cohort study may support lowering the threshold for HTN from 140/90 mmHg to 130/80 mmHg in the UK.