OBJECTIVES : To describe the change in estimated prevalence of hypertension in the ambulatory care population following revision in 2017 of guidelines for the diagnosis and management of hypertension by the American College of Cardiology (ACC) and American Heart Association (AHA).

METHODS : The most recent blood pressure measures were obtained from the Practice Fusion EHR database, which is largely representative of ambulatory care in the United States, for adult patients seen in the last year. Patients were assigned to hypertension stages based on the 2003 and 2017 ACC/AHA hypertension guidelines. The resulting categorizations were tabulated overall and by gender and age to determine impact on prevalence by stage.

RESULTS : Of 9,450,853 patients, 3,483,644 (36.8%) were classified as normal (less than 120/80 mm Hg) under both systems. Under the 2003 guidelines, 3,633,883 (38.4%) were classified as prehypertensive (systolic 120-139 OR diastolic 80-90). Of these, under the 2017 guidelines 1,250,990 (34.4%) are considered to have elevated blood pressure (systolic 120-129 AND diastolic less than 80) while 2,382,893 (65.6%) have Stage 1 hypertension (systolic 130-139 OR diastolic between 80-89). An examination by gender and age showed that for prehypertensive men 65.3% under 45 and 67.4% 45 or older will be reclassified to Stage 1. For women the proportions are similar (64.5% and 64.8%, respectively).

CONCLUSIONS : The 2017 ACC/AHA guidelines will reclassify about two-thirds of patients currently categorized as prehypertensive to Stage 1 hypertension. This may result in a substantial increase in the number of people monitored and engaged in antihypertensive therapy, including non-pharmacologic activities and medication.