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

Abstract

Importance: In the 2017 American College of Cardiology (ACC)/American Heart Association (AHA) guideline, the definition of hypertension was lowered from a blood pressure (BP) of greater than or equal to 140/90 to greater than or equal to 130/80 mm Hg. The new diastolic BP threshold of 80 mm Hg was recommended based on expert opinion and changes the definition of isolated diastolic hypertension (IDH).

Objective: To compare the prevalence of IDH in the United States, by 2017 ACC/AHA and 2003 Joint National Committee (JNC7) definitions, and to characterize cross-sectional and longitudinal associations of IDH with outcomes.

Design, setting, and participants: Cross-sectional analyses of the National Health and Nutrition Examination Survey (NHANES 2013-2016) and longitudinal analyses of the Atherosclerosis Risk in Communities (ARIC) Study (baseline 1990-1992, with follow-up through December 31, 2017). Longitudinal results were validated in 2 external cohorts: (1) the NHANES III (1988-1994) and NHANES 1999-2014 and (2) the Give Us a Clue to Cancer and Heart Disease (CLUE) II cohort (baseline 1989).

Exposures: IDH, by 2017 ACC/AHA (systolic BP <130 mm Hg, diastolic BP ≥80 mm Hg) and by JNC7 (systolic BP <140 mm Hg, diastolic BP ≥90 mm Hg) definitions.

Main outcomes and measures: Weighted estimates for prevalence of IDH in US adults and 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: The study population included 9590 adults from the NHANES (mean [SD] baseline age, 49.6 [17.6] years; 5016 women [52.3%]) and 8703 adults from the ARIC Study (mean [SD] baseline age, 56.0 [5.6] years; 4977 women [57.2%]). The estimated prevalence of IDH in the NHANES was 6.5% by the 2017 ACC/AHA definition and 1.3% by the JNC7 definition (absolute difference, 5.2% [95% CI, 4.7%-5.7%]). Among those newly classified as having IDH, an estimated 0.6% (95% CI, 0.5%-0.6%) also met the guideline threshold for antihypertensive therapy. Compared with normotensive ARIC participants, IDH by the 2017 ACC/AHA definition was not significantly associated with incident ASCVD (n = 1386 events; median follow-up, 25.2 years; hazard ratio [HR], 1.06 [95% CI, 0.89-1.26]), HF (n = 1396 events; HR, 0.91 [95% CI, 0.76-1.09]), or CKD (n = 2433 events; HR, 0.98 [95% CI, 0.65-1.11]). Results were also null for cardiovascular mortality in the 2 external cohorts (eg, HRs of IDH by the 2017 ACC/AHA definition were 1.17 [95% CI, 0.87-1.56] in the NHANES [n = 1012 events] and 1.02 [95% CI, 0.92-1.14] in CLUE II [n = 1497 events]).

Conclusions and relevance: In this analysis of US adults, the estimated prevalence of IDH was more common when defined by the 2017 ACC/AHA BP guideline compared with the JNC7 guideline. However, IDH was not significantly associated with increased risk for cardiovascular outcomes.

Figure 1.. Cumulative Incidence of Cardiovascular Events in the Atherosclerosis Risk in Communities (ARIC) Study, According to Both 2003 Joint National Committee (JNC7) and 2017 American College of Cardiology (ACC)/American Heart Association (AHA) Definitions of Isolated Diastolic Hypertension (IDH)

A, The median follow-up in the sample testing the JNC7 definition was 25.1 years (interquartile range [IQR], 16.6-26.4) in the no IDH group and 25.1 years (IQR, 14.6-26.4) in the IDH group. B, The median follow-up in the sample testing the 2017 ACC/AHA definition was 25.2 years (IQR, 17.4-26.5) in the no IDH group and 25.4 years (IQR, 17.9-26.6) in the IDH group. ASCVD indicates atherosclerotic cardiovascular disease.

Figure 2.. Associations Between Isolated Diastolic Hypertension (IDH), by 2003 Joint National Committee (JNC7) and 2017 American College of Cardiology (ACC)/American Heart Association (AHA) Definitions, and Incident Atherosclerotic Cardiovascular Disease (ASCVD) Events in the Atherosclerosis Risk in Communities (ARIC) Study

All comparisons are vs ARIC Study participants with normal blood pressure (BP) (when studying IDH by the JNC7 definition, this group consists of those with systolic BP <140 mm Hg and diastolic BP <90 mm Hg; when studying IDH by the 2017 ACC/AHA definition, this group consists of those with systolic BP <130 mm Hg and diastolic BP <80 mm Hg). Model 1 is adjusted for age, sex, race-center, and educational attainment. Model 2 is adjusted for model 1 plus smoking status, alcohol consumption, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglycerides, body mass index, antihypertensive medication, diabetes, and estimated glomerular filtration rate. Model 3 is adjusted for model 2 plus baseline systolic BP.