Hospitalization for Hypertensive Crises Doubles in US While Overall Hypertension Control Improves

Annual hospitalizations in the US for hypertensive crisis more than doubled between 2002 and 2014, according to a new analysis of data from the National Inpatient Sample (NIS).

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The research, conducted by investigators from the Smidt Heart Institute at Cedars-Sinai in Los Angeles, also found that the odds of death during those hospitalizations decreased and were similar for women and men. The findings were published in the Journal of the American Heart Association.

The investigators write that the steady rise in hospital admissions for hypertensive crisis have been paralleled by an increase in the overall burden of cardiovascular (CVD) conditions, both escalating despite “contemporaneous improvements in hypertension prevention and control nationwide.”

“Although more people have been able to manage their blood pressure over the last few years, we’re not seeing this improvement translate into fewer hospitalizations for hypertensive crisis,” said lead investigator Joseph E. Ebinger, MD, a clinical cardiologist and director of clinical analytics at the Smidt Heart Institute, in a statement.

National epidemiologic studies indicate that US hypertension control improved significantly during the study period, from 31.8% in 2000 to 53.8% in 2014. And yet, note Ebinger et al, the disease contributes to an estimated 25% of all CV events each year in the US, making hypertension one of the largest modifiable risk factors for CVD.

To better understand what might underlie the dichotomy between improvements in outpatient BP measurements and an increase in severe hypertensive disorders, Ebinger et al studied longitudinal changes in hypertension control overall in the US population.

The authors analyzed data from the NIS to estimate sex-pooled and sex-specific temporal trends in hypertensive crisis hospitalization and fatality rates from 2002-2014.

Multivariable logistic regression models were used to estimate trends in odds of hospitalization and death related to malignant hypertension over time. Covariates included age, race or ethnicity, obesity, hypercholesterolemia, diabetes, and preexisting cardiovascular conditions.

Trends observed

From 2002-2014, investigators identified 918 392 hospitalizations for hypertensive crisis and 4377 related in-hospital deaths. Hypertensive crises, they report, represented 0.23% of all hospitalizations during the study period.

The majority of patients hospitalized for hypertensive crisis were women (58.5%); the average age was 60.2 years and most patients identified as either non-Hispanic White (39.4%) or non-Hispanic Black (34.3%).

Among those who died in the hospital, the majority, again, were women (60%); mean age was 68 years and 43% identified as non-Hispanic White and 37% as non-Hispanic Black.

The majority of patients who died in the hospital (80.4%) had ≥1 cardiovascular condition including renal failure (47%), myocardial infarction (17%), heart failure (44%), and cerebrovascular disease (30%).

In adjusted analyses, Ebinger et al found the odds of hospitalization for hypertensive crisis increased annually for men (OR, 1.083 per year [95% CI, 1.08-1.09]) and women (OR, 1.07 per year [95% CI, 1.07-1.08]), with a higher rate of increase seen in men (P <.001). The adjusted odds of death while hospitalized for hypertensive crisis, however, decreased annually and at a similar rate for men (OR, 0.89 per year [95% CI, 0.86-0.92]) and women (OR, 0.92 per year [95% CI, 0.90-0.94]).

Sexual dimorphism, subgroup diversions

The pronounced increase in admission rates for men vs women, the authors observe, remained even after controlling for CV conditions. The men who were admitted for hypertensive crisis tended to be younger than the women, consistent with evidence that BP control declines later in life for women. However, while women were on average older than the men, they had fewer CV conditions and yet similar case fatality rates. Regarding the several paradoxes related to sex differences the investigators conclude, “The extent to which unmeasured comorbid risk traits could be contributing to this sexual dimorphism is unknown.”

The Cedars-Sinai team also write in the study's discussion that improved control of outpatient BP may be only indirectly related, or completely unrelated, to factors that may predispose to hypertensive crisis in those at risk, eg, medication adherence, drug-drug interactions that potentiate BP, salt sensitivity, and others.

They also suggest that if the schism between increasing rates of severe hypertensive episodes and improving hypertension control represent true nationwide trends, the combined data may “reflect a progressive divergence between subgroups of individuals with hypertension or between subtypes of hypertension or both.” Further studies are warranted on all questions.

Reference: Ebinger JE, Liu Y, Driver M, et al. Sex‐specific temporal trends in hypertensive crisis hospitalizations in the United States. JAMA. 2022;0:e021244.