Original Contribution
Blood pressure treatment and outcomes in hypertensive patients without acute target organ damage: a retrospective cohort

https://doi.org/10.1016/j.ajem.2015.05.036Get rights and content

Abstract

Objectives

The objective is of the study to evaluate the effect of antihypertensive therapy in emergency department (ED) patients with markedly elevated blood pressure (BP) but no signs/symptoms of acute target organ damage (TOD).

Methods

This is a retrospective cohort study of ED patients age 18 years and older with an initial BP greater than or equal to 180/100 mm Hg and no acute TOD, who were discharged with a primary diagnosis of hypertension. Patients were divided based on receipt of antihypertensive therapy and outcomes (ED revisits and mortality) and were compared.

Results

Of 1016 patients, 435 (42.8%) received antihypertensive therapy, primarily (88.5%) oral clonidine. Average age was 49.2 years, and 94.5% were African American. Treated patients more often had a history of hypertension (93.1% vs 84.3%; difference = − 8.8; 95% confidence interval [CI], − 12.5 to − 4.9) and had higher mean initial systolic (202 vs 185 mm Hg; difference = 16.9; 95% CI, − 19.7 to − 14.1) and diastolic (115 vs 106 mm Hg; difference = − 8.6; 95% CI, − 10.3 to − 6.9) BP. Emergency department revisits at 24 hours (4.4% vs 2.4%; difference = − 2.0; 95% CI, − 4.5 to 0.3) and 30 days (18.9% vs 15.2%; difference = − 3.7; 95% CI, − 8.5 to 0.9) and mortality at 30 days (0.2% vs 0.2%; difference = 0; 95% CI, − 1.1 to 0.8) and 1 year (2.1% vs 1.6%; difference = − 0.5; 95% CI, − 2.5 to 1.2) were similar.

Conclusions

Revisits and mortality were similar for ED patients with markedly elevated BP but no acute TOD, whether they were treated with antihypertensive therapy, suggesting relative safety with either approach.

Introduction

Hypertension (HTN) is the most common risk factor for cardiovascular disease in the United States, affecting approximately 75 million individuals and, as such, is a frequently encountered condition among patients treated in the emergency department (ED) [1], [2]. Accordingly, emergency physicians evaluate and treat a variety of hypertensive patients ranging from those who have incidentally discovered elevations in their blood pressure (BP) to those who are critically ill with acute target organ damage (TOD) [3], [4]. Although there is relative uniformity in the approach to treatment of those with true hypertensive emergencies, a clear consensus on the management of patients with severely elevated BP in the ED who lack clinical evidence of acute TOD does not exist.

Significant confusion exists regarding how and when to intervene for patients with markedly elevated BP (ie, ≥ 180/100 mm Hg) but no symptoms of acute TOD, leading to widely divergent practice patterns [5], [6]. Much of this is driven by a scarcity of relevant outcome data, specifically as it pertains to the possible benefit or harm associated with acute BP reduction.

The goal of this investigation is to compare outcomes for ED patients with markedly elevated BP but no signs or symptoms of acute TOD based on whether they received antihypertensive therapy for BP reduction in the ED.

Section snippets

Study design and setting

This was an institutional review board–approved, retrospective cohort study of adult patients between the ages of 18 and 89 years who were discharged from the ED of an urban teaching hospital with a primary diagnosis of HTN between the dates of January 1, 2008, and December 31, 2008.

Study protocol

An initial search of ED billing company data yielded 1798 visits over the study period where HTN was the primary discharge diagnosis. For this analysis, we included only patients with an initial triage BP greater

Characteristics of study subjects

A total of 1016 patients met eligibility criteria, 435 (42.8%) of whom received treatment for elevated BP. As shown in Table 1, patients in both groups (treated vs not treated) were largely African American and relatively young with a mean (SD) age of 49.8 (11.6) vs 48.6 (11.9) years, respectively. Treated patients were more likely to have a history of HTN (93.1% vs 84.3%; difference of − 8.8; 95% CI, − 12.5 to − 4.9) and be on clonidine therapy at baseline (45.0% vs 7.5%; difference of − 36.9; 95%

Discussion

Despite strong sentiment that acute antihypertensive therapy is not necessary in the setting of HTN without acute TOD [3], [8], clinicians often feel inclined to do something when patients present with markedly elevated BP. However, as we demonstrate in this retrospective cohort study, acute BP reduction appears to provide no direct benefit to such patients. Moreover, the occurrence of adverse events was minimal, and death rates were low in both treated and not-treated patients signaling an

Limitations

By only including individuals who were discharged with a primary diagnosis of HTN, this study likely excluded a number of ED patients with marked BP elevation for whom HTN was either a secondary diagnosis or not diagnosed at all. Reviewing charts for consecutive patients may have allowed for greater capture of potentially eligible patients and reduced potential for selection bias. However, such an approach is labor intensive, and, given the low incidence of adverse events, it is unlikely that

Conclusions

In summary, in this single-center, retrospective cohort of predominantly African American ED patients with markedly elevated BP but no signs or symptoms of acute TOD, we found no evidence of benefit with treatment to acutely lower BP. That said, complications related to HTN were infrequent, and the all-cause mortality rate was low with no differences between groups providing a measure of reassurance to ED physicians who use either approach in the care of their acutely hypertensive patients.

References (21)

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