Cardiac and kidney injury linked to managing asymptomatic high blood pressure

Addressing asymptomatic high blood pressure crucial in preventing cardiac and kidney injury, study finds.

In hospitalised patients, blood pressure is routinely monitored. Severe hypertension can cause a heart attack, stroke, or damage to blood arteries and organs such as the heart, brain, kidneys, and eyes. Most hospitalised people, on the other hand, have transiently raised blood pressure without evidence of organ damage, which is known as silent hypertension and is occasionally treated with blood pressure drugs. However, there is little data to guide such therapy decisions.

In a retrospective cohort study, physician-researchers at Beth Israel Deaconess Medical Center (BIDMC), examined the treatment of elevated blood pressure in more than 66,000 older adults who were hospitalized for non-cardiac conditions. The team found that receiving intensive antihypertensive treatment as an inpatient was linked with greater risk of adverse events, particularly for patients receiving the medication intravenously as opposed to orally. The findings, published in JAMA Internal Medicine, do not support treating asymptomatic elevated blood pressure in hospitalized older adults and highlight the need for further study of best practices for management of inpatient blood pressure.

"While the benefits of lowering chronically elevated blood pressure in the outpatient setting are clearly defined and include reductions in mortality and cardiovascular events, better evidence is needed to inform clinical decision-making regarding inpatient blood pressure management," said corresponding author Timothy S. Anderson, MD, MAS, a clinical investigator in the Division of General Medicine at BIDMC. "In the hospital, blood pressure is often elevated due to pain, fever, anxiety, new medication and other hospital factors. It is not clear that treating transient elevations with blood pressure medications is helpful, it may instead result in overtreatment."

Using clinical and pharmacy data from the national Veterans Health Administration (VHA), Anderson and colleagues compared outcomes of hospitalized patients with elevated blood pressure who received intensive blood pressure treatment in the first 48 hours after admission to those who did not. The primary outcome was a composite of adverse effects including inpatient mortality, acute kidney injury, cardiac injury, stroke, and transfer to the intensive care unit.

The cohort included 66,140 older adults, primarily male, who were hospitalized for non-cardiac reasons and had elevated blood pressures in the first 48 hours of hospitalization. One in five patients (or more than 14,000 patients) received intensive treatment for blood pressure, defined as additional antihypertensive medications the patient had not been taking at home prior to hospitalization. Of this group, 18 percent (or more than 2,500 patients) received antihypertensive medication intravenously.

Compared to hospitalized patients with elevated blood pressure who did not receive intensive treatment within the first 48 hours of hospitalization, patients who received antihypertensive medication were at greater risk for adverse clinical outcomes, including cardiac injury, acute kidney injury, and ICU transfer. Receiving antihypertensives intravenously further heightened the risk.

"These findings suggest that the common practice of acutely treating asymptomatic inpatient blood pressure could be harmful and the use of intravenous antihypertensives in particular should be discouraged," said Anderson, who is also an assistant professor of medicine at Harvard Medical School. "Until we have more definitive randomized clinical trial data, our findings suggest that the safest path forward is likely to rethink the underlying reason for inpatient blood pressure measurement and reorient clinical practice. In combination, these findings suggest that pharmacologic treatment of asymptomatic elevated inpatient blood pressure should be the exception rather than the rule."