Hypertension Stage and Risk of Cardiovascular Events

The American College of Cardiology/American Heart Association (ACC/AHA) issued new hypertension guidelines in 2017 that defined new hypertension thresholds. However, according to Kyoung Hye Kong, MD, and colleagues in Seoul, Korea (the Republic of), the evidence cited was based largely on studies conducted with a single measurement of baseline blood pressure.

The researchers recently conducted a study to examine the impact of the change of blood pressure stage according to the 2017 ACC/AHA guideline on cardiovascular events, with baseline and mean blood pressure measurements during follow-up of untreated, low-risk populations. They reported results during a poster session at Kidney Week 2019 in a poster titled The Impact of Change of Blood Pressure Stage according to the 2017 ACC/AHA Guideline on Cardiovascular Events among Untreated Low-Risk Populations: A Nationwide Population-Based Cohort Study.

The retrospective, longitudinal study included 322,562 individuals ≥40 years of age without diabetes mellitus, chronic kidney disease, or previous cardiovascular event who were enrolled in the Korean National Health Service-National Health Screening Cohort between 2002 and 2003. Eligible patients had not taken antihypertensive medications during the follow-up period.

Participants were categorized according to the 2017 guideline based on their baseline and mean blood pressure measurement during follow-up. The primary outcome of interest was newly developed cardiovascular disease and mortality.

During the median follow-up of 10 years, there were 2.51 cardiovascular events per 1000 person-years. In persons with stage 1 hypertension (systolic blood pressure 130 to 139/diastolic blood pressure 80 to 89 mmHg) on both the baseline and mean blood pressure measurements, there was a significantly increased risk of cardiovascular events compared with persons with blood pressure <120/80 mmHg. However, the hazard ratios for cardiovascular events were higher using mean blood pressure rather than the baseline blood pressure measurement.

Following categorization into 16 groups based on blood pressure stages and baseline versus mean blood pressure measurements, the risk of the incidence of cardiovascular disease was significantly lower using blood pressure stage calculated using the mean blood pressure compared with the reference (i.e., the blood pressure stage remained the same between the baseline blood pressure and mean blood pressure) in the population with stage 1 and 2 hypertension.

In conclusion, the researchers said, “Stage 1 and 2 hypertension, defined by the 2017 ACC/AHA guideline, were significantly associated with an increase of cardiovascular events in the analysis with  baseline and mean blood pressure measurement among untreated, low-risk individuals. However, the mean blood pressure was superior to the baseline blood pressure for predicting cardiovascular events. Moreover, the study suggests that physicians need to lower blood pressure stage to prevent the occurrence of cardiovascular disease when their patients, even those at low risk for cardiovascular events, are in stage 1 or 2 hypertension groups at baseline.”

Source: Kong KH, Oh HJ, Ryu D-R. The impact of change of blood pressure stage according to the 2017 ACC/AHA guideline on cardiovascular events among untreated low-risk populations: A nationwide population-based cohort study. Abstract of a poster presented at the American Society of Nephrology Kidney Week 2019 (Abstract TH-PO684), November 7, 2019, Washington, DC.