It's clear that asymptomatic hypertension is common in hospitalized patients. What to do about it, though, is murkier, according to ACP Member Timothy Anderson, MD, MAS.
While there's agreement that consistent systolic readings below 100 mm Hg or over 180 mm Hg are warning signs that may require intervention, goals for inpatient blood pressure are less well defined, Dr. Anderson said in a lecture at Hypertension 2020, which was held virtually last September. “We don't really know if applying outpatient targets is ideal in an inpatient setting, or if a more permissive approach may be correlated with better outcomes,” he said.
Patients with inpatient hypertension might not necessarily have hypertension as an outpatient, said Dr. Anderson, who is an instructor of medicine at Harvard Medical School in the Division of General Medicine at Beth Israel Deaconess Medical Center in Boston.
In a retrospective electronic health record (EHR) study of 14,915 older adults with hypertension hospitalized for noncardiac conditions in the Veterans Administration (VA) Health System, published by BMJ in September 2018, Dr. Anderson and his team found that almost half of those who had high inpatient blood pressures, defined as multiple systolic values over 160 mm Hg, had well-controlled blood pressure at home.
“Perhaps using the term ‘elevated blood pressure’ is better than using the term ‘inpatient hypertension,’ because we really don't always know that inpatient recordings are truly diagnostic for a patient having hypertension,” he said. He offered advice on whether to acutely treat elevated blood pressure in the hospital and whether to intensify outpatient medications during hospitalization and at discharge.
Treating without symptoms
There are well-established guidelines on how to handle acute symptomatic hypertension in the hospital, but guidelines on asymptomatic hypertension are lacking, Dr. Anderson said. “Neither the cardiovascular community nor the hospital medicine community has established practice guidelines, and this is largely due to a dearth of evidence in this field that hopefully is slowly starting to be filled through novel investigations.”
Some data on current clinical practice, primarily from single-center academic studies, suggest that single doses of antihypertensive medications are often given for inpatient hypertension as needed, including both oral drugs and IV hydralazine and labetalol, Dr. Anderson said. In a study published by the Journal of Hospital Medicine in March 2019, researchers at the University of California, San Francisco, looked at the treatment of asymptomatic hypertension, defined as at least one measurement over 160/90 mm Hg. Of the 2,306 inpatients, 11% received IV medications. After a quality improvement initiative aimed at decreasing use of these drugs, that proportion decreased to 7% without any observed negative effects, Dr. Anderson said.
Another study of 174 patients at a hospital in Detroit, published in the Journal of Hospital Medicine in March 2016, found that those receiving IV hydralazine had a mean decrease in systolic blood pressure of 17 mm Hg and those receiving IV labetalol had a mean decrease of 12 mm Hg.
“A third of the patients who received an IV medication actually had a blood pressure reduction of more than a quarter within six hours, which exceeds our typical recommendations for blood pressure lowering for both hypertensive emergency and in the outpatient setting, and certainly suggests that it's a high risk for overcorrection with IV treatment,” Dr. Anderson said.
He noted that multiple studies have suggested no difference in major cardiac events or in later uncontrolled hypertension when elevated asymptomatic blood pressure is treated immediately in the ED versus addressed via a normal outpatient process of care. “I think the most important step is to assess for signs of end-organ damage that would suggest that this is not an asymptomatic issue, but a symptomatic issue, for which we know treatment is important,” Dr. Anderson said.
In addition, he stressed that no data support the use of IV antihypertensive medications in patients who have no symptoms. “One thing I often reflect on is that we would not consider treating elevated outpatient blood pressures with as-needed medicines as acceptable clinical practice, and so it's been unclear to me why this practice is so persistent in the inpatient setting,” he said.
Intensifying outpatient medications
There's an argument that hospitalization can be an opportunity to help improve patients' blood pressure control, Dr. Anderson said. “We have more time with patients, we may have more resources like the patient pharmacists or nutrition to focus on hypertension management, and we certainly have more recordings than we can often get in the clinic setting,” he said. “The contrasting viewpoint is that adjusting chronic medications when people are actually hospitalized for other conditions may cause more harm than benefit.”
Many patients may understandably prioritize the condition they're hospitalized for and may prefer not to focus on a secondary condition, Dr. Anderson said. In addition, patients are at high risk for medication confusion, adverse drug events, and readmissions during the postdischarge period, so it may not be the best time to change medications and increase risk of polypharmacy.
In their 2018 BMJ study, Dr. Anderson and his research group examined VA patients hospitalized for noncardiac conditions such as pneumonia, venous thromboembolism, and urinary tract infections, and then looked at how often they were discharged with changes to their home blood pressure medication regimens. Medication intensification at discharge was defined as a new medication that wasn't being taken before the hospital stay or a significant dose increase of a pre-existing medication.
Overall, 14% of patients were discharged with intensified medications. No link was found between comorbid conditions or life expectancy and these medication changes, but inpatient blood pressure values appeared to be related. Among patients whose blood pressure was well controlled before admission, 8% of those without elevated inpatient values, 24% of those with moderately elevated inpatient values, and 40% of those with severely elevated inpatient values were discharged with intensified regimens, indicating that inpatient rather than outpatient blood pressure was driving treatment decisions, Dr. Anderson said.
He and his coauthors next used a propensity-matched cohort of 4,056 VA patients to compare those whose medications were intensified at discharge versus those whose medications weren't. In results published in August 2019 by JAMA Internal Medicine, they found a significantly increased risk for readmission and serious adverse events among the former group. However, there was no between-group difference in cardiovascular events at one year, suggesting that intensification did not reduce risk. “Surprisingly, we saw a trend in the opposite direction: patients who received intensifications being almost significantly more likely to have a cardiovascular event,” Dr. Anderson said.
A stratified analysis found that risk for harm was highest among patients who had well-controlled home blood pressure, which could mean that they are particularly prone to overtreatment, Dr. Anderson noted. In addition, he and his coauthors found that outpatient blood pressure values at one year did not differ significantly between the two groups. “One reason for this is that nearly half of the patients discharged with intensifications were no longer taking these intensifications one year later,” he said.
Pearls for clinical practice
More research on management of asymptomatic hypertension in the hospital is necessary, Dr. Anderson said. He noted that observational studies could examine the association between inpatient and outpatient blood pressure, while randomized trials could evaluate inpatient and discharge treatments in patients who seem likely to benefit. In addition, Dr. Anderson said, pragmatic EHR-based interventions could help hospitalists and other inpatient clinicians make good decisions about blood pressure management (e.g., by surfacing home blood pressure values when inpatient medications are being ordered).
Dr. Anderson concluded his talk by offering clinical pearls from an Annals for Hospitalists article he coauthored, published in April 2020 by Annals of Internal Medicine. He recommended teaching trainees to always gather data on home blood pressure values as a first step and consider factors like access to care and home medication use to determine whether patients are likely to commit to or benefit from a medication change.
“Of course, it's always important to recheck high inpatient blood pressure before making any treatment decisions,” he said. “It's important to contextualize your patient, thinking about things like likelihood to benefit, life expectancy, and other causes of high blood pressures in the hospital that may be transient.”
In addition, tread lightly, since perihospitalization is a high-risk period and a change in blood pressure regimen may not be a patient's immediate priority, Dr. Anderson advised. “Consider focusing on outpatient communication rather than making a treatment change right then and there,” he said.
Last, remember to partner with patients in developing a care plan. “We know that a large percentage of patients have medication confusion when they're discharged from the hospital, and this confusion can increase the risk of being readmitted, so minimizing medication changes is kind of always a good fallback plan,” Dr. Anderson said. “And if it's not the patient's goal to focus on blood pressure, it may not be the right time to make a change, even if they may benefit down the road from revisiting this decision.”