Reference: JAMA. 2020 Jan 28;323(4):329-338
As American culture continues to super-size servings and SUVs, it should come as no surprise that there is a similar trend with medical diagnoses. An additional 12.1 million Americans were recently labeled as “hypertensive” based on isolated diastolic hypertension (IDH) after the 2017 AHA/ACC Guideline for High Blood Pressure in Adults defined high blood pressure as ≥ 130/80 (compared to the 2003 JNC7 level of ≥ 140/90). Of those 12.1 million patients, 4.2 million were newly eligible for treatment with antihypertensives based on a diastolic blood pressure of ≥ 80 mm Hg but systolic blood pressure < 130, which defines IDH. The first systematic review of blood pressure studies (Arguedas et al. 2009) analyzed data from 7 trials that used lower diastolic blood pressure cut-offs as treatment targets, and concluded that these lower targets did not reduce cardiovascular mortality. However, investigators and guideline development panels still struggle to accept the dichotomy of what should happen based on decades-old observational associations between higher blood pressure and cardiovascular mortality and what the evidence shows does happen.
An Irish group recently examined prevalence data from the National Health and Nutrition Examination Survey 2013-2016 (NHANES) and Atherosclerosis Risk in Communities 1990-2017 (ARIC) studies comparing AHA/ACC versus JNC7 definitions of IDH. Rates of incident heart failure, chronic kidney disease, athersclerotic cardiovascular disease (a composite of nonfatal myocardial infarction, nonfatal ischemic stroke, and cardiovascular death), and all-cause mortality were also validated in two external cohorts (NHANES 1999-2014 and the Give Us a Clue to Cancer and Heart Disease [CLUE] II cohort [baseline 1989]).
Of the 9,590 adults from NHANES evaluated, 1.3% met criteria for IDH by the JNC7 definition and 6.5% by the AHA/ACC guideline, a difference of 5.2%. This difference in prevalence was most pronounced in younger age categories. Fortunately, few patients were recommended by either the JNC7 or the AHA/ACC guidelines to initiate drug therapy based on IDH alone. The ARIC cohort looked at 14,348 adults aged 46-69 (median age 55), finding IDH in 2% as defined by JNC7 and 11% by the AHA/ACC classification. Those with IDH by either definition were less likely than normotensive participants to smoke, but more likely to be younger, black, overweight, or have higher cholesterol. Comparing the different thresholds for IDH diagnosis, there was no difference in all-cause mortality or cardiovascular mortality in validation analyses combining NHANES III and NHANES 1999-2014 data at median 9.8 years follow-up. Likewise, the CLUE II cohort with median 28.7 years follow-up showed no association between IDH by 2017 ACC/AHA guidelines and all-cause or cardiovascular mortality.
So alas, here we are, eleven years after the first meta-analysis concluded that there was no mortality benefit with lower diastolic blood pressure targets with the AHA/ACC guideline again making a recommendation that is not evidence-based. The current study reinforces that more aggressive treatment of isolated diastolic blood pressure appears to confer no mortality benefit while labeling people with a disease. Five percent of the population of the US is a large number. These data demonstrate that 12 million more Americans are at increased risk of paying more for their life insurance while likely living just as long as those labeled normotensive.
For more information, see the topic Hypertension in DynaMed.
The following link is to a recent EBSCO blog entry co-authored by Dr. DeGeorge exploring some of the external implications of the 2017 ACC/AHA 2017 hypertension guidelines:
https://health.ebsco.com/blog/article/whats-the-target-of-the-new-acc-aha-performance-measures
Below is a link to a paper from November 2019 co-authored by Dr. Brian Alper, founder of DynaMed, considering ways to improve consistency between recommendations for evaluation and management of hypertension:
https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2755862
DynaMed EBM Focus Editorial Team
This EBM Focus was written by Katharine DeGeorge, MD, MS, Associate Professor of Family Medicine at the University of Virginia and Clinical Editor at DynaMed. Edited by Alan Ehrlich, MD, Executive Editor at DynaMed and Associate Professor in Family Medicine at the University of Massachusetts Medical School, Dan Randall, MD, Deputy Editor for Internal Medicine at DynaMed.