Guidelines on the management of hypertension and hypertensive emergencies warn that excessive reduction of blood pressure (BP) can lead to renal, cerebral, or coronary ischemia and should be avoided; however, clinicians often treat acute severe hypertension, which occurs in non-ICU patients with IV antihypertensives even though there is no substantive evidence that hypotensive agents improve outcomes in the absence of acute target organ damage.
To help address this issue, investigators at Yale New Haven Health System conducted a retrospective analysis to evaluate the effect of IV antihypertensive treatment on clinical outcomes in patients without acute target organ damage who develop severe hypertension (i.e., acute severe BP elevations) during hospitalization.
Patients aged 18 years or older who were hospitalized for 2 or more days and up to 30 days between January 6, 2016, and March 31, 2020, were included in this study. Patients were excluded if they had been hospitalized for hypertensive emergency; were admitted to the maternity, intensive care, or research units; had received vasopressors 6 hours prior to the development of severe hypertension; had missing data; or if they had falsely elevated BP readings (i.e., systolic BP decreased to <180 mmHg or diastolic BP dropped to <110 mmHg within 1 hours of the index severe BP elevation without the administration of antihypertensive medications during this time period).
Severe inpatient hypertension was defined as the first documented severe BP elevation (systolic BP >180 mmHg or diastolic BP >100 mm Hg) after admission. BP readings in the emergency department was excluded. IV antihypertensive administration included the use of one of four parenteral preparations, hydralazine, labetalol, metoprolol, or nicardipine, which were administered within 3 hours of severe hypertension.
The main outcomes in the study included the development of myocardial infarction (MI), acute kidney injury (AKI), and inpatient death. To be included as a positive finding, any of the above events had to have occurred 3 hours or more after developing severe inpatient hypertension. To account for confounders, overlap propensity score weighting was performed of the following parameters: demographic data, comorbidities, laboratory values on admission, nonantihypertensive medications that affect BP given before severe inpatient hypertension development (e.g., nonsteroidal anti-inflammatory agents, corticosteroids, or IV crystalloid fluids), vital signs on admission, and BP at the time of severe hypertension development. Further analyses were conducted on patients with cardiovascular and noncardiovascular disease admissions.
A total of 224,265 admissions met the study criteria and of these, 20,377 (9%) patients developed severe hypertension. Among these patients, 5% received IV antihypertensives (n = 1,059) within 3 hours of developing severe hypertension. The median age of the patients who developed severe hypertension was 73 years. The majority of these patients (78%) had a history of hypertension.
The median systolic BP, diastolic BP, and mean arterial pressure (MAP) readings at discharge for those who were treated with IV antihypertensives were 141, 74, and 97 mmHg, respectively, compared with BP readings of 140, 73, and 96 mmHg, respectively, in the untreated group. Patients who received IV antihypertensives were more likely to develop an MI (5.9%) compared with the untreated group (3.6%), which represented a 52% increase in risk based on an overlap propensity weighted (OPW) hazard ratio (HR) (OPW HR 1.52; 95% CI, 1.08-2.14). Although AKI and death were more common in the unadjusted analysis, following overlap propensity weighting, there was no difference between the treated and untreated groups.
Whereas having a cardiovascular admission did not affect risk of an adverse outcome, IV antihypertensive–treated patients admitted to a medical ward who developed severe hypertension had a 74% greater risk of developing an MI (HR 1.74; 95% CI, 1.17-2.59). This increased risk was not observed among surgical patients. Patients treated with IV antihypertensives had a greater risk of MI than patients treated with oral antihypertensives.
The authors called into the question the practice of administering IV antihypertensive within 3 hours of developing severe BP elevations in patients with no evidence of acute target organ damage. While dissuading use of the parenteral agents in this circumstance, they recommended caution if they are utilized.
This paper highlights an area in which pharmacists can educate on the risks associated with the use of IV antihypertensives in this population. If administered, pharmacists need to closely monitor and document any adverse events that occur.
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Published March 6, 2023