Masked hypertension ‘real phenomenon’ driving cardiometabolic risk
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BOSTON — Masked hypertension is an underappreciated phenomenon that confers extra risk for CVD and chronic kidney disease, and simple steps such as home BP monitoring and stepped-up medications can improve outcomes, according to a speaker.
“Masked hypertension is there; it takes a little extra work to find it, and when present, it disturbs that comfortable feeling of ‘That is one well-controlled hypertensive patient,’” Raymond R. Townsend, MD, FAHA, professor of medicine and director of the Hypertension Program at the Hospital of the University of Pennsylvania, told Healio. “Most surprising is it is not limited to people with office-based hypertension. It is a phenomenon throughout the population. People on no drugs thought to be ‘normotensive’ who have elevated BP outside the office also have additional risk from that out-of-office [BP] elevation.”
Defining masked hypertension
There are several definitions of masked hypertension: a simple explanation is when there is a discordance between the BP the clinician sees in the office vs. an elevated BP at home or elsewhere, Townsend said during a presentation at the Cardiometabolic Health Congress.
“Masked hypertension should be just masked BP, because it happens in normotensive people,” Townsend said. “If you’re a ‘no’ [for hypertension] in the office but have higher than current goal [BP measurements] as defined by the current guidelines for home, ambulatory or kiosk-related BP, then you fit the definition.”
In the International Database of Ambulatory BP in Relation to Cardiovascular Outcomes (IDACO) study, published in Hypertension in 2014, researchers cross-classified 8,237 untreated participants enrolled in 12 population studies, using 140/ 90 mm Hg, 130/ 80 mm Hg, 135/ 85 mm Hg, and 120 / 70 mm Hg as hypertension thresholds for conventional, 24-hour, daytime and nighttime BP.
Depending on time intervals chosen, white-coat and masked hypertension frequencies ranged from 6.3% to 12.5% and from 9.7% to 19.6%, respectively, Townsend said. During 91,046 person-years of follow-up, 729 participants experienced a CV event.
HRs associated with white-coat hypertension progressively weakened across all measurement categories; however, the HRs comparing masked hypertension with normotension were all significant (P < .0001), ranging from 1.76 to 2.03.
“When people talk about masked hypertension, you begin to see some of the confusion,” Townsend said. “Is it a daytime value? Is it only the nighttime that matters? Is it a combination of both or is it the full 24 hours? The answer is, yes. It is all of the above. When we talk about masked hypertension, we do have a bit of a semantics issue here. When you vary the definition, you will find that 10% to 20% of the general population [have masked hypertension].”
In the SPRINT trial, which included treated participants at high CV risk, whether randomly assigned to an intensive BP goal or standard care, the rate of masked hypertension was one in three in both arms, Townsend said.
“At the end of the day, you can say that masked hypertension tends to occur in one in four or one in five of the population,” Townsend said.
Masked hypertension matters
In a report from the Chronic Renal Insufficiency Cohort (CRIC) study published in the Journal of the American Society of Nephrology, researchers demonstrated that the presence of masked uncontrolled hypertension and higher mean 24-hour BP were independently associated with high risk for CVD and kidney disease progression; participants with reverse dipper BP were at high risk for kidney disease progression, stroke and peripheral artery disease compared with those who experienced a nighttime dip in BP.
“When you have masked hypertension, compared to a person with BP controlled inside and outside the office, you are looking at a doubling of CV outcomes, no matter how you slice or dice the definition of masked hypertension,” Townsend said.
Research lacking
There are few studies currently assessing masked hypertension; none of which are actively recruiting in the United States, Townsend said. Current research gaps include better understanding the mechanisms behind masked hypertension, a need to understand the difference between a well-rested, standardized in-office BP vs. free-range ambulatory BP monitoring values, and appropriate treatments.
When a patient presents with masked hypertension, whether controlled or uncontrolled, the clinician should check for the presence of obstructive sleep apnea, consider stepping up BP medications and consider home BP monitoring when CKD is present.
“This is a real phenomenon,” Townsend said. “One in four or one in five [people] has masked hypertension. That is at least a double-digit percent; it is at least worth our time to acknowledge that this exists. It does seem to confer extra CV [and] renal risk when present.”
References:
- Asayama K, et al. Hypertension. 2014;doi:10.1161/HYPERTENSIONAHA.114.03614.
- Drawz PE, et al. Clin J Am Soc Nephrol. 2016;doi:10.2215/CJN.08530815.
- Rahman M, et al. J Am Soc Neph. 2020;doi:10.1681/ASN.2020030236.
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Townsend R. Importance of assessment and potential treatment of masked hypertension. Presented at: Cardiometabolic Health Congress; Oct. 19-22, 2022; Boston.
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