Risk factors for hypertensive crisis in adult patients: a systematic review
Authors: Benenson Irina , Waldron Frederick A. , Jadotte Yuri T. , Dreker Margaret (Peggy) , Holly Cheryl 
Published: February 2021

ABSTRACT

Objective:
The objective of this review was to examine the best available evidence on the risk factors for hypertensive crisis in adult patients with hypertension.

Introduction:
Hypertensive crisis is an acute severe elevation in blood pressure, which can present as hypertensive urgency or emergency. In contrast to hypertensive urgency, which is a markedly elevated blood pressure without acute target organ damage, hypertensive emergency is associated with equally high blood pressure in the presence of potentially life-threatening target organ damage, such as myocardial infarction, stroke, pulmonary edema, or acute kidney injury. Hypertensive crisis results in adverse clinical outcomes and high utilization of health care.

Inclusion criteria:
This review considered studies of non-modifiable factors (age, sex, ethnicity) and modifiable factors such as socioeconomic factors (lack of medical insurance, lack of access to medical care), adherence to medical therapies, presence of comorbidities (diabetes, hyperlipidemia, coronary artery disease, history of stroke, chronic kidney disease, congestive heart failure), and substance abuse in persons of either sex, older than 18 years with a diagnosis of hypertension.

Methods:
A search of four databases, seven gray literature sites, and relevant organizational websites revealed 11,387 titles. After duplicates were removed, 9183 studies were screened by the title and abstract for eligibility. Forty full-text articles were retrieved, and each was assessed for eligibility. Twenty-one articles were excluded. The remaining 19 full-text studies were critically appraised and included in this review.

Results:
The risk of hypertensive crisis was higher in patients with a history of comorbid cardiovascular conditions, such as chronic kidney disease (odds ratio [OR] 2.899, 95% confidence interval [CI] 1.32, 6.364), coronary artery disease (OR 1.654, 95% CI 1.232, 2.222), or stroke (OR 1.769, 95% CI 1.218, 2.571). Patients with hypertensive emergency had higher mean systolic blood pressure (mean difference [MD] 2.413, 95% CI 0.477, 4.350) and diastolic blood pressure (MD 2.043, 95% CI 0.624, 3.461). Hypertensive emergency was more common in men (OR 1.390, 95% CI 1.207,1.601), older patients (MD 5.282, 95% CI 3.229, 7.335), and those with diabetes (OR 1.723, 95% CI 1.485, 2.000) and hyperlipidemia (OR 2.028, 95% CI 1.642, 2.505). Non-adherence to antihypertensive medications (OR 0.939, 95% CI 0.647,1.363) and hypertensive diagnosis unawareness (OR 0.807, 95% CI 0.564, 1.154) did not increase the risk of hypertensive emergency.

Conclusions:
Comorbid cardiac, renal, and cerebral comorbidities (coronary artery disease, congestive heart failure, cerebrovascular disease, and chronic kidney disease) increase the risk of hypertensive crisis. The risk of hypertensive crisis is higher in patients with unhealthy alcohol and recreational drug use. Systolic and diastolic blood pressure are marginally higher in patients with hypertensive emergency compared to patients with hypertensive urgency. Since these differences are small and not clinically significant, clinicians should rely on other symptoms and signs to differentiate between hypertensive urgency and hypertensive emergency. The risk of hypertensive emergency is higher in older adults. The coexistence of diabetes, hyperlipidemia, and chronic kidney disease increases the risk of hypertensive emergency.

Systematic review registration number:
PROSPERO (CRD42019140093)