What is the best way to measure blood pressure?
Bare those arms, folks. To get the most accurate measure, let patients chill for a few minutes, and then measure their blood pressure on a completely bare arm. Does a difference of 4 mm systolic and 6 mm to 7 mm diastolic matter? It might; especially when deciding whether to add a second or third drug. Also, remember to confirm office-based blood pressures with an out-of-office measurement (either ambulatory blood pressure monitoring or home blood pressure measurements), as many patients have white coat hypertension. (LOE = 2c)(www.essentialevidenceplus.com)
Ozone S, Shaku F, Sato M, Takayashiki A, Tsutsumi M, Maeno T. Comparison of blood pressure measurements on the bare arm, over a sleeve, and over a rolled-up sleeve in the elderly. Fam Pract 2016;33(5):517-522.
Study design: Cross-sectional
Funding source: Self-funded or unfunded
Setting: Outpatient (primary care)
It is important that we measure blood pressure in our offices in the same way it is done in studies of hypertension diagnosis and treatment. Otherwise, we risk misclassifying patients and may either overtreat or undertreat them. This simple cross-sectional study recruited 186 adults in a Japanese primary care clinic and in 2 adult daycare facilities. Blood pressure was measured using an automated cuff in 3 conditions: a completely bare arm, an arm covered by a sleeve no more than 1 mm thick to the wrist (a cardigan with a 1-mm thick sleeve was provided, if necessary), or an arm with the sleeve rolled up over the elbow. All patients were first asked to sit in a chair for 5 minutes prior to the measurement, with their arm supported and level. The researchers systematically varied the order in which blood pressure was measured. For each condition, the final blood pressure was the average of 3 measurements. The participants had a mean age of 75 years, 62% were female, and approximately 63% were hypertensive. The mean blood pressures were 129/67 taken on a bare arm, 133/73 on a fully sleeved arm, and 133/74 on an arm with the rolled-up sleeve. The difference persisted after adjusting for age and measurement order in an ANOVA model. It is also interesting that the mean blood pressure decreased from the first measurement (135/74) to the second measurement (131/71) and to the third measurement (129/70).
Mark H. Ebell, MD, MS
University of Georgia
How well does monitoring blood pressure for 30 minutes in the office compare with a single office reading in patients suspected of having white coat hypertension?
In this study in a single practice, monitoring blood pressure readings in the office for 30 minutes resulted in markedly lower readings compared with the last office reading (~ 23/12 mm Hg lower) and the clinicians report they would be much less likely to intensify treatment if they used these readings. It remains to be seen whether this result occurs in other settings or whether patient outcomes are improved. (LOE = 2b)(www.essentialevidenceplus.com)
Bos MJ, Buis S. Thirty-minute office blood pressure monitoring in primary care. Ann Fam Med 2017;15(2):120-123.
This study took place over a 6-month period in a single primary care practice in the Netherlands. The authors recruited every patient who underwent 30-minute office blood pressure monitoring (OBP30) for medical reasons. For the OBP30 the patient sits alone in a quiet area with an automated unit that measures and records blood pressure every 5 minutes. The final OBP30 reading is the simple average of the 6 readings. For this study, the authors compared the OBP30 with the last "regular" office reading. They also asked the clinician a bunch of questions about why they ordered the OBP30 and how they would use the information. Almost 60% of the 201 patients in this study were women with an average age of 69 years. The authors report that approximately 20% of the patients had diabetes and 20% had cardiovascular disease, but they don't report how many had hypertension. The most common reasons for ordering the OBP30 included suspected white coat hypertension, newly diagnosed hypertension, inconsistent office readings, and monitoring medication effectiveness. On average, the systolic OBP30 readings were 23 mm Hg lower than the office readings, and the diastolic OBP30 readings were 12 mm Hg lower than in the office. For the patients with suspected white coat hypertension, the differences were 30 mm Hg and 14 mm Hg, respectively. For each of the other various categories of clinical circumstances, the differences between OBP30 and the office readings ranged from 14 to 28 mm Hg and 8 to 17 mm Hg, respectively. Approximately 80% of the clinicians would have intensified treatment based solely on the office blood pressure readings compared with only 25% who would have intensified treatment based on the OBP30. This is a cute little study, but I am not sure how to apply this. The existing data of treating hypertension are based on a diagnosis established after 3 elevated readings on separate occasions, and a few studies have suggested that white coat hypertension is not an altogether benign condition.
Henry C. Barry, MD, MS
Michigan State University
East Lansing, MI
Does intensive systolic blood pressure lowering in older patients increase the likelihood of renal dysfunction?
In this post-hoc analysis of the previously published SPRINT trial, lowering the systolic blood pressure of patients who are at increased risk of cardiovascular events (average age 66 years) will decrease their risk of cardiovascular disease but increase their likelihood of developing moderate renal dysfunction. It will not, at least over 3 years, increase their likelihood of developing end-stage renal disease. (LOE = 1b)(www.essentialevidenceplus.com)
Beddhu S, Rocco MV, Toto R, et al, for the SPRINT Research Group. Effects of intensive systolic blood pressure control on kidney and cardiovascular outcomes in persons without kidney disease. A secondary analysis of a randomized trial. Ann Intern Med 2017;167(6):375-383.
Study design: Randomized controlled trial (nonblinded)
Funding source: Government
Setting: Outpatient (any)
This report is a subgroup analysis of the SPRINT (Systolic blood Pressure INtervention Trial), which enrolled patients with high blood pressure and elevated cardiovascular risk. This analysis was limited to the 6662 participants, mean age 66 years, with a baseline estimated glomerular filtration rate (GFR) of at least 60 mL/min/1.73 m2, who represented approximately 70% of the total original cohort. The participants were randomly assigned, allocation concealment unknown, to be treated to reach an intensive (120 mm Hg or lower) or standard (140 mm Hg or lower) systolic blood pressure. The actual blood pressure difference between the 2 groups was an average 15 mm Hg. Significantly more people in lower blood pressure group experienced a significant decline in kidney function, defined as a 30% or greater decline in GFR to less than 60 mL/min/1.73 m2 (number needed to treat to harm = 38; 95% CI 29 - 53). But, as in the full SPRINT report, the risk of death or cardiovascular event over 3 years was lower with lower systolic blood pressure. None of the participants developed end-stage renal disease. Post-hoc analyses such as this one are risky to interpret, but in this case the results echo the analysis in the original report.
Allen F. Shaughnessy, PharmD, MMedEd
Professor of Family Medicine
Is it better to evaluate for orthostatic hypotension after 1 minute or 3 minutes of standing?
Finding an orthostatic drop within the first minute after standing more accurately predicts dizziness and future adverse events than finding it at the currently recommended 3 minutes. (LOE = 1b)(www.essentialevidenceplus.com)
Juraschek SP, Daya N, Rawlings AM, et al. Association of history of dizziness and long-term adverse outcomes with early vs later orthostatic hypotension assessment times in middle-aged adults. JAMA Intern Med 2017; Jul 24. doi:10.1001/jamainternmed.2017.2937.
Study design: Cohort (prospective)
As part of a larger study, these researchers investigated the timing for evaluating an orthostatic blood pressure drop in 11,429 patients (54% women, 26% black) recruited from the general public. Approximately 10% of these patients (n = 1138) reported a history of dizziness on standing. The middle-aged patients (average age 54 years) had their blood pressure automatically measured every 25 seconds, up to 5 times, while standing following 20 minutes of lying down. Patients with a history of dizziness were allowed to remain seated until they felt comfortable standing. Orthostatic hypotension was defined as a decrease of 20 mm Hg systolic or 10 mm Hg diastolic blood pressure. Having an orthostatic drop within the first minute (25 - 62 seconds) was predictive of higher odds of dizziness (odds ratio 1.49; 95% CI 1.18-1.89). It also was associated with the highest risk of fracture, syncope, and death over the subsequent 23 years.
In patients older than 65 years with elevated low-density lipoprotein levels but no cardiovascular disease, is cholesterol lowering effective in decreasing mortality or morbidity?
If a patient makes it to 65 years old without developing cardiovascular disease, lowering his or her cholesterol level at this point is not effective, and might even be harmful if treatment is started at age 75. Given the lack of benefit also shown in other studies, it might be time to stop checking—and treating—high cholesterol in these age groups. (LOE = 1b-)(www.essentialevidenceplus.com)
Han BH, Sutin D, Williamson JD, et al, for the ALLHAT Collaborative Research Group. Effect of statin treatment vs usual care on primary cardiovascular prevention among older adults. The ALLHAT-LLT randomized clinical trial. JAMA Intern Med 2017; doi:10.1001/jamainternmed.2017.1442.
This report is an analysis of a trial that evaluated the primary prevention of cardiovascular disease using cholesterol lowering. It focused on patients who were at least 65 years old and had an elevated fasting low-density lipoprotein cholesterol (LDL-C) level (120 - 189 mg/dL [3.1 - 4.9 millimoles/L]). The Lipid-Lowering Trial (LLT) component of the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT-LLT) study enrolled 2867 adults 65 years or older with hypertension but without baseline atherosclerotic cardiovascular disease. The patients were randomized, using concealed allocation, to receive usual care or pravastatin 40 mg daily. Most of the patients in the usual care group were not treated with a statin. Over the 6 years of follow-up, all-cause mortality was not different between the 2 treatment groups for patients 65 to 74 years of age (hazard ratio for pravastatin vs usual care = 1.08 (95% CI, 0.85-1.37; P = .55) and was almost statistically higher for patients at least 75 years of age (hazard ratio of pravastatin vs usual care = 1.34 (0.98-1.84; P = .07). Rates of coronary heart disease events were not different between the groups in either age group. Analysis was by intention to treat. Given that this is a post-hoc analysis, the researchers did not provide a power calculation and there might be a small difference in rates that was not see in this study.
POEMs are provided by Essential Evidence Plus, a point-of-care clinical decision support system published by Wiley-Blackwell. For more information, please see http://www.essentialevidenceplus.com(www.essentialevidenceplus.com).
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