The Relationship Between Stroke Risk and Peak Home Systolic Blood Pressure

Average peak home systolic blood pressure (SBP) measurements that exceed 175 mm Hg may indicate significant risk for stroke within 5 years, according to study findings published in Hypertension Research.

Among patients with hypertension, home BP measurements, compared with office BP measurements, may be more effective at indicating risk for future cardiovascular (CV) events and hypertensive organ damage. Investigators aimed to analyze associations between CV events and the pathological threshold of average peak home BP in patients with at least 1 CV risk factor.

The investigators used data from the prospective, observational, multicenter nationwide J-HOP (Japan Morning Surge-Home Blood Pressure) study that enrolled patients from 2005 to 2012 (follow-up through March 2015) and included an extended long-term follow-up (6.2 years) conducted December 2017 to May 2018. The study included 4231 ambulatory outpatients (mean age, 64.9±10.9 years; 46.7% men; 79% receiving antihypertension medication) with at least 1 risk factor for cardiovascular disease. Patients were enrolled by 75 physicians in 71 institutions.

The investigators divided patients into quintiles (Q) of peak home SBP. For 13 days, participants were instructed to take their own BP measurements 3 times in the morning and 3 times in the evening (78 measurements overall; actual number of measurements, 69±14). There were significant differences in the average peak home SBP ranging from 135.4 mm Hg to 186.2 mm Hg.

During extended follow-up analysis of risk for stroke, coronary artery disease (CAD), and atherosclerotic cardiovascular disease (ASCVD; fatal or nonfatal) there were 94 strokes and 124 CAD events. Pathological threshold of average peak home SBP for 5-year stroke risk was determined to be 176 mm Hg. Patients with average peak home SBP in the highest quintile vs lowest quintile had an adjusted hazard ratio (aHR) of 4.39 for risk for stroke (95% CI, 1.85-10.43) and an aHR of 2.04 for risk for ASCVD (95% CI, 1.24-3.36).

The number of times peak home SBP exceeded 175 mm Hg had a linear association with risk for stroke. This risk was greatest in the first 5 years (aHR, 22.66; 95% CI, 2.98-172.10). The highest risk for stroke was in patients with morning and evening values in the highest quintile of average peak home SBP (Q5; ≥173.0 mm Hg) vs all other quintiles. Patients in the lowest quintile (Q1; average peak home SBP <142.7 mm Hg) experienced few stroke events. After 5 years, patients with average peak home SBP in Q4 had a cumulative stroke incident rate approaching that of patients in Q5.

Findings remained consistent regardless of data being stratified by only morning vs only evening readings of average peak home SBP, by patient age (<65 years vs ≥65 years), or by whether or not patients had history of ASCVD. Researchers found no relation between CAD risk and quintiles of average peak home SBP.

Study limitations include lack of generalizability and the presence of pharmacological antihypertensive agents in nearly 80% of participants. There may also be an unaccounted for risk for BP surge for measurements taken in a sitting position.

“Peak home BP was a strong risk factor for stroke, especially within the first 5 years,” the investigators wrote. “We propose exaggerated peak home SBP > 175 mm Hg as an early and strong novel risk factor for stroke.”

Disclosure: One study author declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.

This article originally appeared on The Cardiology Advisor