Use this easy “3 out of 10 rule” to quickly sift through home blood pressure readings and identify patients with uncontrolled hypertension who require pharmacologic management.1
Strength of recommendation
B: Based on a single, good quality, multicenter trial.
Sharman JE, Blizzard L, Kosmala W, et al. Pragmatic method using blood pressure diaries to assess blood pressure control. Ann Fam Med. 2016;14:63-69.
A 64-year-old woman presents to your office for a follow-up visit for her hypertension. She is currently managed on lisinopril 20 mg/d and hydrochlorothiazide 25 mg/d without any problems. The patient’s blood pressure (BP) in the office today is 148/84 mm Hg, but her home blood pressure (HBP) readings are much lower (see TABLE). Should you increase her lisinopril dose today?
Hypertension has been diagnosed on the basis of office readings of BP for almost a century, but the readings can be so inaccurate that they are not useful.2 The US Preventive Services Task Force recommends the use of ambulatory blood pressure monitoring (ABPM) to accurately diagnose hypertension in all patients, while The Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC 7) recommends ABPM for patients suspected of having white-coat hypertension and any patient with resistant hypertension,3,4 but ABPM is not always acceptable to patients.5
Guidelines recommend HBP monitoring for long-term follow-up of hypertension
The European Society of Hypertension practice guideline on HBP monitoring suggests that HBP values <130/80 mm Hg may be considered normal, while a mean HBP ≥135/85 mm Hg is considered elevated.9 The guideline recommends HBP monitoring for 3 to 7 days prior to a patient’s follow-up appointment with 2 readings taken one to 2 minutes apart in the morning and evening.9 In a busy clinic, averaging all of these home values can be time-consuming.
So how can primary care physicians accurately and efficiently streamline the process? This study sought to answer that question.
When 3 of 10 readings are elevated, it’s predictive
This multicenter trial compared HBP monitoring to 24-hour ABPM in 286 patients with uncomplicated essential hypertension to determine the optimal percentage of HBP readings needed to diagnose uncontrolled BP (HBP ≥135/85 mm Hg). Patients were included if they were diagnosed with uncomplicated hypertension, not pregnant, ≥18 years of age, and taking ≤3 antihypertensive medications. Medication compliance was verified by a study nurse at a clinic visit. Patients were excluded if they had a significant abnormal left ventricular mass index (women >59 g/m2; men >64 g/m2), coronary artery or renal disease, secondary hypertension, serum creatinine exceeding 1.6 mg/dL, aortic valve stenosis, upper limb obstructive atherosclerosis, or BP >180/100 mm Hg.
Approximately half of the participants were women (53%), average body mass index was 29.4 kg/m2, and the average number of hypertension medications being taken was 2.4. The patients were instructed to take 2 BP readings (one minute apart) at home 3 times daily, in the morning (between 6 am and 10 am), at noon, and in the evening (between 6 pm and 10 pm), and to record only the second reading for 7 days. Only the morning and evening readings were used for analysis in the study. The 24-hour ABP was measured every 30 minutes during the daytime hours and every 60 minutes overnight. The primary outcome was to determine the optimal number of systolic HBP readings above goal (135 mm Hg), from the last 10 recordings, that would best predict elevated 24-hour ABP. Secondary outcomes were various cardiovascular markers of target end-organ damage.