13 Hypertension

 Hypertension

Learning Objectives

 

  • Describe proper blood pressure measurement technique
  • Identify the blood pressure goals recommended by JNC-8
  • Choose appropriate blood pressure medications
  • Describe side effects of common antihypertensive agents

 

JNC 8 (January 2014)

  • Goal <140/90 for <60 yo
  • Goal <150/90 for 60 yo and older
  • Lifestyle modification still first line
  • DM2 and Chronic Kidney Disease (CKD) –> Goal is <140/90 for all ages
  • Thiazides, CCBs, ACEis (ARB if cough) first line
    (exception: ACEis/ARBs not first line in AA patients)
  • Beta-blockers now considered second line
  • Do not use ACEi and ARB together
  • Use ACEi (ARB if cough) first line if CKD (DM2 no longer specified here)

Prepared by Wayne Altman, MD, FAAFP (Tufts Family Medicine)

 

Reading: Management of Hypertension

 

Treating Hypertension: JNC- 8 (2014) vs AHA/ACC (2017)

 

In 2014, The Eighth Joint National Committee released evidence-based guidelines for the management of high blood pressure in adults, including treatment thresholds, target BP goals, and specific medications. These were more robust, evidence-based evidence based guidelines that expanded on the predominantly, expert consensus-based guidelines of JNC-7, released 10 years prior. A major change in JNC-8 was the shift to more permissive (higher) blood pressure goals. A major contributor to this decision was the ACCORD BP 1 trial which failed to show statistically significant morbidity and mortality benefits for diabetics when they were treated with stricter blood pressure goals. A summary of JNC-8 recommendations can be found in the Tufts Mobile Medicards.2

 

In 2017, the American Heart Association and the American College of Cardiology released another set of hypertension guidelines that proposed new hypertension definitions, and advised stricter blood pressure control due to the mortality benefits seen from the SPRINT trial (published in 2015 after JNC 8)3. These guidelines focused on stricter treatment thresholds, lower target BP goals, called for more accurate blood pressure monitoring, and highlighted the need for lifestyle changes. Earlier this year, the American Academy of Family Physicians criticized the AHA/ACC guidelines for disproportionately weighing the SPRINT trial and not considering the totality of evidence. The AAFP announced that they would not be adopting these guidelines and would continue to endorse JNC-8.4

 

Why did stricter BP control have a mortality benefit in SPRINT but not ACCORD BP? ACCORD BP was about half the size of SPRINT and therefore may have been insufficiently powered. On the other hand SPRINT was stopped early due to the mortality benefit seen between the two groups, yet truncated RCTs can be associated with an overestimation of effect size.5 In SPRINT, the significant benefit was in rates of heart failure and all cause cardiovascular mortality, but there was no difference in rates of stroke, myocardial infarction, and acute coronary syndrome.

 

Guidelines from abroad:

 

  • European Society of Hypertension/European Society of Cardiology 2014 guidelines recommend blood pressure goal of <140/90 in all patients unless over 80 yo in which case they recommend <150/90 is suggested, (Diabetes: recommend DBP <85)|
  • Canada’s 2017 guidelines released on the diagnosis, management and treatment of hypertension emphasized the importance of accurate BP measurement and established a threshold for hypertension as >135/85 or >130/80 with diabetes.

 

So where do we go from here? Can we reach a general consensus on how to define hypertension and how to manage patients with hypertension?

 

 

JNC-8 (2014) AHA/ACC Guidelines (2017-2018)
Methodology Initial systematic review of RCTs from 1996 to 2013, with subsequent review of RCT evidence and recommendations based on standardized protocols Disproportionate weight to the SPRINT trial, an RCT assessing standard vs. strict blood pressure treatment goals.
Definitions Normal: <120/<80

Pre-hypertension: 120-139/80-89

Stage 1: 140-159/90-99

Stage 2: >160/>100

Normal: <120/80

Elevated: SBP 120-129

Stage 1: 130-139/80-89

Stage 2: >140/>90

Thresholds for initiating treatment >60 yo: >150/90
<60 yo or comorbid conditions        (DM, CKD): >140/90
>130 SBP or >80 DBP if history of CVD or >10% ASCVD risk.
>140/90 if no clinical CVD and <10% ASCVD risk
Treatment Goals <140/90 if <60 yo or comorbid conditions (DM, CKD); (Grade E recommendation)

<150/90 if >60 yo (Grade A recommendation)

<130/80
Medication Selection Non-African American:                Thiazide, ACEi/ARB, or CCB

African-American: Thiazide or CCB

Non-African American:      Thiazide, ACEi/ARB, or CCB

African-American:Thiazide or CCB

Treatment Algorithm Start 1 med→ follow up 1 mo. → add med or increase dose if not at goal BP. 1 med for stage 1.
2 meds for stage 2 with different mechanism of action
The Numbers ACCORD BP

N=4733

2632 intensive BP control

2371 less intensive

 

No sig difference in nonfatal MI, nonfatal stroke, CV death
NNT non fatal stroke 476/yr

Fatal Stroke 588/yr

 

NNH: Adverse Events attributable to BP meds 49

From SPRINT

N=9,361

4678 targeted SBP at <120

4683 targeted SBP at 135-139

 

NNT primary outcome (1st MI, stroke, CHF or death) 63

 

NNH (adverse events possibly or definitely related to intervention) 45

Pitfalls Based primarily on data prior to 2013; limited data prior to 2013 that assessed the long term sequelae of overtreatment. -New definition increases number    of Americans with hypertension   from 72 million to 103 million                    (32–>46% of US adults)
-Chair of SPRINT trial was also Chair of the AHA/ACC guidelines

Conclusions

While much of the focus has been on the definitions of hypertension and thresholds for treatment, there is a good amount of overlap between the ACA/AHA and JNC 8 guidelines:

 

  1. The ACA/AHA and JNC-8 guidelines both recognize that lifestyle modifications (DASH diet, weight loss, exercise, smoking cessation) are first line and are paramount for reducing morbidity and mortality associated with elevated BP. These interventions do not carry any of the risks associated with medications.
  2. Proper measurement of blood pressure (appropriate cuff size, pt seated in a chair with feet on floor and back support, no talking by patient or person measuring BP) is vital. The SPRINT trial identifies a possible variation of 20 points on SBP related to improper measurement.
  3. Ambulatory blood pressure monitoring may be helpful in circumventing white coat hypertension and placing patients on unnecessary medications. The Canadian guidelines incorporate ambulatory monitoring into their initial diagnosis of hypertension.
  4. Medication management for Non-African American patients should feature Thiazides ACEis, ARBs, and CCBs. African American patients should be prescribed Thiazides and CCBs as ACEi/ARBs have been shown to have reduced efficacy in lowering blood pressure in AA patients.

 

As for how to deal with the differences in blood pressure guidelines, it is necessary to account for the different demographics of the patients in both trials. SPRINT (2017) enrolled patients who were at high risk for cardiovascular events, therefore the risks and benefits associated with treatment regimens in SPRINT are most applicable to patients with CV disease or high risk for CV disease, and not as applicable for patients who are at lower risk for cardiovascular disease or who are more frail.

 

So high-risk patients (ASCVD>10%), diabetics and non-frail older adults may benefit from lower BP targets per the ACC/AHA Guidelines. In particular, patients with heart failure may benefit significantly from intensive blood pressure control. Healthy adults (<65 with no evidence of cardiovascular disease) with elevated blood pressure would likely benefit most from focusing on lifestyle modifications and initiation of medication at a threshold of 140/90 as the risk-benefit ratio is much more narrow in this population.

 

Patients with limited mobility (e.g. frail elderly) would benefit from more conservative BP targets, independent of their comorbidities because the risk of falls and acute kidney injury may outweigh the benefits of stricter blood pressure control.

 

Ultimately, there is not a one-sized fits all approach and the treatment of hypertension represents another opportunity to engage our patients in shared decision-making.

 

 

Braidie Campbell M19, C. Dan Earley M19, Wayne Altman MD

 

REFERENCES

  1. The ACCORD Study Group, et al. Effects of intensive blood-pressure control in type 2 diabetes mellitus. N Engl J Med. 2010;362:1575–85

 

  1. Tufts Mobile Medicards: http://tusk.tufts.edu/mobi/view/content/Medical/3052/1741982

 

  1.  The SPRINT research Group. A randomized trial of intensive versus standard blood-pressure control. N Engl J Med. 2015;373(22):2103–16

 

  1.  Chris Crawford. “AAFP decides not to endorse AHA/ACC Hypertension Guideline- continues to endorse JNC-8 guidelines” https://www.aafp.org/news/health-of-the-public/20171212notendorseaha-accgdlne.html

 

  1. Bassler D, Briel M, Montori VM, et al. Stopping Randomized Trials Early for Benefit and Estimation of Treatment Effects Systematic Review and Meta-regression Analysis. JAMA. 2010;303(12):1180–1187. doi:10.1001/jama.2010.310

 

  1. Munter, Paul, et al. “Potential US Population Impact of the 2017 ACC/AHA High Blood Pressure Guideline.” Circulation, vol. 137, no. 2, 2017, pp. 109-118., doi: 10.1161/circulationaha.117.032582.

 

 

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