Clinical question
What are the risks for asymptomatic patients who present with markedly elevated blood pressure (BP)?
Bottom line
Patients with markedly elevated BP have about a 40% risk of serious adverse events at 18 months if untreated. The risk for treated patients ranges from 14% at 1 month to 1.2% at 6 months. For most asymptomatic patients with BPs above 180/110 mm Hg, addition or initiation of oral agents at presentation with outpatient follow-up is reasonable.
Evidence
An RCT found the following:
Hospitalized men (N = 143; mean BP 186/121 mm Hg) were randomized to hydrochlorothiazide, reserpine, and hydralazine versus placebo.1
-At 18 months, the rate of retinal hemorrhage, stroke, dissecting aneurysm, myocardial infarction, or heart failure (HF) was 3% versus 39% for placebo (number needed to treat = 3).
Cohort studies of treated patients found the following:
In 58 535 American outpatients (mean BP 185/96 mm Hg), 73% had known hypertension, about 60% were taking 2 or more BP drugs, and about 25% had known cardiovascular disease (CVD).2
-At 6 months, the rate of myocardial infarction, stroke, or transient ischemic attack was 1.2%.
-There was no difference between inpatient and outpatient management.
-Inaccurate BPs are suspected, as 4.6% of about 2 million office visits had BPs above 180/110 mm Hg.
Austrian patients (N = 384; BP > 220/120 mm Hg) received oral treatment and had numerous investigations and long-term follow-up.3
-At 4 years, the rate of CVD, HF, or atrial fibrillation was 23%.
In 164 Swiss primary care outpatients (mean BP 198/101 mm Hg),4 90% were asymptomatic or “urgent” (ie, had nonspecific symptoms: headache or dizziness).
-At 1 year, the rate of CVD, HF, or peripheral vascular disease was 12.8%.
-Limitations included the treating physician reporting outcomes.
In 91 inner-city African and Hispanic patients (mean BP 209/128 mm Hg),5 about 66% had nonspecific symptoms and 50% had known CVD. Most were treated with oral agents (clonidine) and had no follow-up.
-At 1 month, the CVD, HF, or encephalopathy rate was 14%.
Context
The definition of hypertensive urgency varies.
Most hypertensive urgencies occur in those with known hypertension,2,4,6 often owing to medication nonadherence.2,5
Hypertension with acute symptoms associated with end organ damage, such as chest pain or confusion,7 requires immediate intravenous treatment.6
Implementation
Before diagnosing hypertensive urgency, ensure correct BP measurement. Talking, improperly sized cuffs, and arms held below the heart can falsely elevate BP.7 For most asymptomatic patients with BPs above 180/110 mm Hg, outpatient treatment2 with conventional oral agents is appropriate. The optimal speed of BP lowering is unknown,8 but rapid reduction is discouraged.9 A reasonable approach is to target a BP of about 160/100 mm Hg, follow up promptly to ensure medication tolerability and compliance, and continue to lower BP gradually. These patients often need more than 1 antihypertensive drug.10 Combination pills can improve adherence and lower costs.
Notes
Tools for Practice articles in Canadian Family Physician (CFP) are adapted from articles published on the Alberta College of Family Physicians (ACFP) website, summarizing medical evidence with a focus on topical issues and practice-modifying information. The ACFP summaries and the series in CFP are coordinated by Dr G. Michael Allan, and the summaries are co-authored by at least 1 practising family physician and are peer reviewed. Feedback is welcome and can be sent to toolsforpractice{at}cfpc.ca. Archived articles are available on the ACFP website: www.acfp.ca.
Footnotes
Competing interests
None declared
The opinions expressed in Tools for Practice articles are those of the authors and do not necessarily mirror the perspective and policy of the Alberta College of Family Physicians.
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