The cardiovascular (CV) risk patterns of systolic blood pressure (SBP) and diastolic blood pressure (DBP) measurements differ by clinical outcomes, and determining a patient’s ideal blood pressure (BP) goals may depend on the cardiovascular event they are experiencing most accomplished is risk, according to results published in the Journal of the American College of Cardiology.
In the United States, the current guidelines for target BP recommend a value less than 130/80 mm Hg for almost all patients. However, these guidelines are largely based on studies that have independently assessed SBP and DBP. The patient’s risk assessment can be improved by combining both BP components at the same time, as described in the Multiple Risk Factor Intervention Trial and the Reanalysis of the Framingham Heart Study.
For the current study, researchers used data from the Antihypertensive and Lipid-Lowering Treatment for the Prevention of Heart Attack (ALLHAT) (ClinicalTrials.gov Identifier: NCT00000542) to simultaneously assess risk patterns for cardiovascular events and all-cause mortality associated with SBP and DBP .
The primary composite endpoint was the simultaneous impact of SBP and DBP on the associated risk of all-cause mortality, congestive heart failure (CHF), myocardial infarction (MI), or stroke. ALLHAT randomly assigned adults to amlodipine, chlorthalidone, or lisinopril and used proportional hazard regression to assess the simultaneous association of repeated SBP / DBP measurements with the primary composite endpoint and each endpoint alone.
For the current study, the researchers enrolled 33,357 participants with 458,079 total blood pressure measurements (median: 14 per participant, interquartile range [IQR] 11-18). For the median 4.4 years (IQR 3.6-5.4 years), participants were followed; 24.4% experienced 1 or more of the endpoints within the primary composite endpoint. When evaluating SBP and DBP at the same time, the researchers found different risk patterns depending on the result.
For the primary combined endpoint of all-cause mortality and CHF, the researchers reported a U-shaped association with SBP / DBP, while the SBP / DBP corresponding to the lowest risk for these individual endpoints differed. For example 150/70 mm Hg (Hazard Ratio [HR] 0.79; CI 0.77-0.82) was associated with the lowest HR for all-cause mortality relative to 120/80 mm Hg compared to 135/75 mm Hg for CHF (cause-specific HR [csHR] 0.86; CI 0.83-0.89).
The lowest risk levels for MI were 120/80 mm Hg, with even 125/75 mm Hg being associated with a significantly higher risk (csHR 1.07; CI 1.03-1.06). Conversely, a linear association between blood pressure and stroke was observed, with a higher csHR associated with higher SBP / DBP levels.
In the stratified analysis, the lowest risk for the primary composite endpoint in participants under 65 years of age was lower SBP values and similar DBP values compared to participants age 65 years or older (122/82 mm Hg vs., respectively). The analyzes, stratified according to diabetes mellitus status and gender, were qualitatively similar. Sensitivity analyzes showed the lowest risk of cardiovascular death for DBP levels that were lower than for non-cardiovascular deaths. A lower risk of heart attack or cardiovascular death and heart attack or cardiovascular death was also observed with lower DBPs than with a heart attack or heart attack alone.
“Our results suggest that blood pressure goals may need to be changed depending on which cardiovascular outcome the patient is most at risk for,” the study authors noted. “For example, for a particular person with a previous stroke, more aggressive blood pressure reductions may be warranted in light of the linear association observed, while for a person with a history of previous myocardial infarction, care would need to be taken to avoid excessive hypotension.”
The researchers acknowledged that BP targets cannot be based on the current analysis alone because the study was observational. They also acknowledged the possibility that different measurement methods could lead to different optimal BP combinations. Further prospective studies, which also consider the associated influence of SBP / DBP on cardiovascular risk, are required.
Itoga NK, Tawfik DS, Montez-Rath ME, et al. Contributions of systolic and diastolic blood pressure to cardiovascular outcomes in the ALLHAT study. J. Am. Coll. Cardiol. Published online October 18, 2021. doi: 10.1016 / jacc.2021.08.035
This article originally appeared on The Cardiology Advisor