BACKGROUND AND PURPOSE:

• The new 2017 ACC/AHA hypertension definition lowered the diastolic BP threshold to 80 mm Hg, changing the definition of isolated diastolic hypertension (IDH)
• McEvoy et al. (JAMA, 2020)
  • Compared the prevalence of IDH in the United States, by 2017 ACC/AHA and 2003 Joint National Committee (JNC7) definitions

METHODS:

• Cross-sectional and longitudinal analyses
• Data sources
  • Cross-sectional analyses
    • National Health and Nutrition Examination Survey (NHANES 2013 to 2016)
  • Longitudinal analyses
    • Atherosclerosis Risk in Communities (ARIC) Study (baseline 1990 to 1992, with follow-up through December 31, 2017)
  • External cohorts for validation
    • NHANES III (1988 to 1994) and NHANES (1999 to 2014)
    • Give Us a Clue to Cancer and Heart Disease (CLUE) II cohort (baseline 1989)
• Exposures
  • IDH as defined by 2017 ACC/AHA
    • Systolic BP <130 mm Hg, diastolic BP ≥80 mm Hg
  • IDH as defined by JNC7
    • Systolic BP <140 mm Hg, diastolic BP ≥90 mm Hg
• Primary outcomes
  • Prevalence of IDH
  • Prevalence of US adults recommended BP pharmacotherapy by the 2017 ACC/AHA guideline based solely on the presence of IDH
  • Risk of incident atherosclerotic cardiovascular disease (ASCVD), heart failure (HF), and chronic kidney disease (CKD) in the ARIC Study

RESULTS:

• 9590 adults from the NHANES study | 8703 adults from the ARIC Study
  • NHANES
    • Mean baseline age 49.6 years; 52.3% women
  • ARIC
    • Mean baseline age 56.0 years; 57.2% women
• Estimated prevalence of IDH
  • By 2017 ACC/AHA standards: 6.5%
  • By JNC7 standards: 1.3%
  • Absolute difference 5.2% (95% CI, 4.7 to 5.7%]
• Among those newly classified 2017 standards
  • Met criteria for antihypertensive therapy: 0.6% (95% CI, 0.5 to 0.6%)
• IDH as defined by the 2017 standards was not significantly associated with
  • ASCVD
    • Hazard ratio (HR) 1.06 (95% CI, 0.89 to 1.26)
    • 1386 events; median follow-up 25.2 years
  • HF
    • HR 0.91 (95% CI, 0.76 to 1.09)
    • n = 1396 events
  • CKD
    • HR 0.98 (95% CI, 0.65 to 1.11)
    • n = 2433 events
• IDH as defined by 2017 standards was also not significantly associated with cardiovascular mortality in the 2 external cohorts
  • NHANES
    • HR 1.17 (95% CI, 0.87 to 1.56); n = 1012 events
  • CLUE II
    • HR 1.02 (95% CI, 0.92 to 1.14); n = 1497 events

CONCLUSION:

• Under the 2017 ACC/AHA guidelines, the estimated prevalence of IDH was higher in the adult US population than it was under the JNC7 guideline
• However, IDH using the new threshold was not associated with an increased risk of worse cardiovascular outcomes
• The authors state

…the above results, demonstrating that diastolic BPs between 80 and 90 mm Hg have no adverse prognostic significance when systolic BP is well controlled, appear to be supported indirectly by other observational data

Learn More – Primary Sources:

Association of Isolated Diastolic Hypertension as Defined by the 2017 ACC/AHA Blood Pressure Guideline With Incident Cardiovascular Outcomes

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