HIGH BLOOD PRESSURE





Acronyms



SCREENING RECOMMENDATIONS


  • Use the follow-up interval for the reading (SBP or DBP) that is most out of range
Blood pressure reading (mmHg) Follow-up
< 120 / 80 Recheck in 2 years
120 - 139 / 80 - 89 Recheck in 1 year
140 - 159 / 90 - 99 Recheck within 2 months
160 - 179 / 100 - 110 Recheck within 1 month
≥ 180 / ≥ 110 Treat now or recheck within 1 week




BLOOD PRESSURE PHYSIOLOGY



MEASURING BLOOD PRESSURE




  • Arm circumference should be measured at the midpoint of the acromion and olecranon
Arm circumference (cm) Cuff size
22 - 26 Small adult
(size 12X22 cm)
27 - 34 Standard adult
(size 16X30 cm)
35 - 44 Large adult
(size 16X36 cm)
45 - 52 Extra-large adults (thigh cuff)
(size 16X42 cm)


  • Reference [1,2,47,51]
Proper BP measurement technique
Measurement preparation
  • The patient should relax for 3 - 5 minutes while sitting in a chair with legs uncrossed, feet flat on the floor, and back supported
  • Caffeine, exercise, and smoking should be avoided within 30 minutes of the measurement
  • The patient should empty their bladder before the measurement if necessary
  • The arm should be bare if possible, but a shirtsleeve should not be rolled up if it is too tight because it may act as a tourniquet
Comments
  • If back is not supported, SBP and DBP may be increased by 5 - 15 and 6 mmHg, respectively
  • Crossed legs during a BP measurement can raise SBP by 5 - 8 mmHg and DBP by 3 - 5 mmHg
  • STUDY
    A small study (N=113) published in 2021 found that different rest periods of 0, 2, and 5 minutes before automated BP measurements did not affect the average reading. [PMID 34601959]
Measurement technique
  • Use an upper arm cuff
  • Arm should be supported (e.g., resting on a table), but not by the patient
  • Position the middle of the cuff on the upper arm at the level of the right atrium (midpoint of the sternum)
  • Use correct cuff size (see cuff size above)
Comments
  • If the upper arm is below the level of the right atrium (e.g., when the arm is hanging down while in the seated position), the readings will be too high
  • The cuffed arm should be held up by the observer or resting on a table at heart level. If the arm is held up by the patient, BP will be raised.
Measurement frequency
  • At first clinic visit or reading, measure blood pressure on both arms. The arm that gives the highest reading should be used from then on.
  • At least 2 measurements should be made (at least 1 minute apart), and the average should be used
  • If taking BP medication, take two readings in the morning before taking meds and two readings in the evening
  • Use the average of ≥ 2 readings on ≥ 2 separate occasions to estimate BP. Ideally, BP monitoring period will be ≥ 7 days.
Comments
  • Persistent BP differences between arms of ≥ 10 mmHg are common and occur in 11.2% of people with hypertension and 4% of the general population. Significant BP arm differences can be a sign of coarctation of the aorta (see secondary causes), but this condition is rare, affecting only 0.1% of patients with hypertension.
  • STUDIES
    A study that included over 38,000 patients found that, on average, the median change in clinic SBP on a second reading among patients with hypertension who had a high initial reading was -8 mmHg. [PMID 29710186]
  • In another study, 35% of people with a BP measurement of 140 - 159/90 - 99 mm Hg on their first measurement had a BP < 140/90 mm Hg when the average of 3 measurements was used [51]
  • A small study published in 2021 (N=102) found that a 30-second time interval between automated BP measurements was as accurate and reliable as a 60-second interval [PMID 34488436]


BLOOD PRESSURE GOALS


HOME BLOOD PRESSURE MONITORS



STORE-BASED BLOOD PRESSURE MACHINES



AMBULATORY MONITORING



HYPERTENSION









  • Percentages represent prevalence among patients with hypertension
Causes of secondary hypertension
(percentages represent prevalence among patients with hypertension)
Obstructive sleep apnea (25 - 50%)
  • Signs and symptoms: snoring; daytime sleepiness; obesity; apnea during sleep
  • Diagnosis: sleep study
Renal vascular disease (5 - 34%)
  • Signs and symptoms: resistant hypertension; hypertension of abrupt onset; young females (fibromuscular hyperplasia); abdominal bruit
  • Diagnosis: renal doppler ultrasound; MRA/CT
  • Treatment: A randomized controlled trial found no benefit of renal artery stenting in atherosclerotic renal artery stenosis (see renal artery stenosis below)
Primary aldosteronism (8 - 20%)
Drugs and alcohol (2 - 4%)
Renal parenchymal disease (1 - 2%)
  • Signs and symptoms: family history of polycystic kidney disease; abnormal urinalysis; elevated serum creatinine
  • Diagnosis: renal ultrasound
Aortic coarctation (0.1%)
  • Signs and symptoms: young patient (< 30 years) with hypertension; BP higher in upper extremities than in lower extremities; absent femoral pulses
  • Diagnosis: Echocardiogram
Cushing's syndrome (rare, < 0.1%)
  • Signs and symptoms: central obesity; moon face; supraclavicular fat pads; violaceous striae, hirsutism
  • Diagnosis: see HPA axis testing
Hyper / hypothyroidism (rare, < 0.1%)
  • Signs and symptoms: depends on cause
  • Diagnosis: TSH
Primary hyperparathyroidism (rare)
  • Signs and symptoms: none
  • Diagnosis: Serum calcium
Pheochromocytoma (rare, 2 - 8 cases per million persons annually) [27]
  • Signs and symptoms: resistant hypertension; paroxysmal hypertension with headache, sweating, palpitations, and pallor
  • Diagnosis: 24-hour urinary fractionated metanephrines or plasma metanephrines; CT/MRI of adrenals [47]
Congenital adrenal hyperplasia (rare)
  • Signs and symptoms: virilization or incomplete masculinization
  • Diagnosis: Newborn screening, hormone studies
Acromegaly (rare)
  • Signs and symptoms: large hands, feet, head
  • Diagnosis: Growth hormone level




  • Reference [50]
AHA 2018 recommendations for treating resistant hypertension
  • Start with Step 1 and proceed to the next step if blood pressure is still elevated
Step 1
  • Ensure that the patient meets the definition of resistant hypertension
  • Maximize lifestyle interventions
    • Low sodium diet (< 2400 mg/day)
    • ≥ 6 hours of uninterrupted sleep
    • Weight loss and exercise
  • STUDY
    A small study (N=60) found that three 40-minute weekly exercise sessions significantly lowered blood pressure in patients with resistant hypertension. [PMID 34347008]
Step 2
Step 3
Step 4
Step 5
  • Add hydralazine 25 mg three times a day and titrate
  • Patients with heart failure and reduced EF should receive isosorbide mononitrate with hydralazine
  • Hydralazine can cause tachycardia and edema, so it should be given with a beta blocker and loop diuretic
Step 6
  • Substitute minoxidil 2.5 mg two to three times a day for hydralazine and titrate
  • Minoxidil can cause tachycardia and edema, so it should be given with a beta blocker and loop diuretic


HYPERTENSIVE EMERGENCY



HYPERTENSIVE URGENCY



MEDICATIONS THAT CAN RAISE BLOOD PRESSURE



LIFESTYLE CHANGES TO LOWER BLOOD PRESSURE

  • Heart rate reserve (HRR) = Max heart rate [208 - (age X 0.7)] minus resting heart rate. Add percent of HRR to resting heart rate for target rate.
  • References [1,5,6,47,53]
Effect of lifestyle changes on blood pressure
Weight loss
  • SBP reduction: 1 mmHg reduction for every 2.2 lbs (1 kg) of weight loss
  • Maintain a BMI of 18 - 25. See weight loss for more.
Adopt a DASH diet
  • SBP reduction: 8 - 14 mmHg
  • Consume a diet rich in fruits, vegetables, whole grains, and low-fat dairy products, with reduced content of saturated and total fat (see DASH diet for more)
Decrease sodium intake
  • SBP reduction: 2 - 8 mmHg
  • Optimal goal is < 1500 mg of sodium/day, but a 1000 mg/day reduction can be beneficial. See sodium below.
Increase potassium intake
  • SBP reduction: 4 - 5 mmHg
  • Potassium intake of 3500 – 5000 mg/d (89 - 128 mEq), preferably from dietary sources, is recommended. Daily intake of 4 - 5 servings of fruits and vegetables usually provides 1500 to >3000 mg (38 to >77 mEq). See potassium content of foods and potassium homeostasis for more.
Increase exercise
  • Aerobic: SBP reduction - 5 mmHg | 90 – 150 min/wk at 65 - 75% of heart rate reserve
  • Dynamic resistance: SBP reduction - 4 mmHg | 90 - 150 min/wk at 50 - 80% of 1 rep maximum. 6 exercises, 3 sets/exercise, 10 repetitions/set
  • Isometric resistance: SBP reduction - 5 mmHg | 4 sets, each for 2 minutes (e.g., hand grip), 1 min rest between exercises, 30% – 40% maximum contraction, 3 sessions/wk
Moderate alcohol consumption
  • BP reduction: 4 mmHg
  • No more than 2 drinks/day for males, and 1 drink/day for females
Smoking cessation


RENAL ARTERY STENOSIS (RAS)


RCT
CORAL Trial - Renal Artery Stenting + Medical Therapy vs Medical Therapy, NEJM (2014) [PubMed abstract]
  • The CORAL trial enrolled 947 patients with atherosclerotic renal artery stenosis
Main inclusion criteria
  • Severe renal artery stenosis (defined as ≥ 80%; or ≥ 60% with a systolic pressure gradient of at least 20 mmHg)
  • SBP ≥ 155 mm Hg while receiving ≥ 2 BP meds OR GFR < 60 ml/min
Main exclusion criteria
  • Fibromuscular dysplasia
  • Chronic kidney disease other than ischemic nephropathy
  • Serum creatinine > 4 mg/dl
  • Vascular lesion requiring more than one stent
Baseline characteristics
  • Average age 69 years
  • Average systolic BP - 150 mmHg
  • Average GFR - 58 ml/min
  • Average % stenosis - 67%
  • Bilateral stenosis - 20%
Randomized treatment groups
  • Group 1 (459 patients): Renal artery stent + medical therapy
  • Group 2 (472 patients): Medical therapy alone
  • Medical therapy consisted of antiplatelet therapy, candesartan, amlodipine, atorvastatin, and HCTZ if needed
  • Target blood pressure was < 140/90 in general, and < 130/80 in patients with diabetes or chronic kidney disease
Primary outcome: Composite of death from cardiovascular or kidney causes, stroke, heart attack, hospitalization for congestive heart failure, progressive kidney disease, or the need for permanent kidney-replacement therapy
Results

Duration: Median of 43 months
Outcome Stent None Comparisons
Primary outcome 35.1% 35.8% HR 0.94, 95%CI [0.76 - 1.17], p=0.58
Overall mortality 13.7% 16.1% HR 0.80, 95%CI [0.58 - 1.12], p=0.20
Progressive kidney disease (defined as 30% reduction in GFR) 16.8% 18.9% HR 0.86, 95%CI [0.64 - 1.17], p=0.34
  • Average SBP was slightly lower in the Stent group (diff -2.3 mmHg, p=0.03)

Findings: Renal-artery stenting did not confer a significant benefit with respect to the prevention of clinical events when added to comprehensive, multifactorial medical therapy in people with atherosclerotic renal-artery stenosis and hypertension or chronic kidney disease.




RENAL DENERVATION FOR RESISTANT HYPERTENSION



BEETROOT JUICE TO LOWER BLOOD PRESSURE


RCT
Beetroot juice vs Nitrate-depleted beetroot juice for Hypertension, Hypertension (2015) [PubMed abstract]
  • The study enrolled 68 patients with hypertension
Main inclusion criteria
  • Age 18 - 85 years
  • Ambulatory daytime BP > 130/85 mmHg
  • BMI 18 - 40
Main exclusion criteria
  • History of CVD
  • CrCl < 50 ml/min
  • History of heart failure
Baseline characteristics
  • Average age 56 years
  • Average ambulatory BP - 148/88
  • Average # of Hypertension drugs - 1
Randomized treatment groups
  • Group 1 (32 patients): Beetroot juice 250 ml (∼6.4 mmol of nitrates) every morning for 4 weeks
  • Group 2 (32 patients): Nitrate-depleted beetroot juice for 4 weeks
  • Half the randomized patients were drug-naïve and half were receiving hypertension meds
  • The study included a 2-week run-in phase in which baseline BP was assessed. The study also included a 2-week post-treatment phase where BP was assessed again.
Primary outcome: Change in clinic, ambulatory, and home BP compared with placebo
Results

Duration: 4 weeks
Outcome Beetroot juice Placebo Comparisons
Change in ambulatory BP (SBP / DBP) -6.6 / -4.3 mmHg +0.8 / +0.9 mmHg p<0.001
Change in clinic BP (SBP / DBP) -8.7 / -3.2 mmHg -1 / -0.7 mmHg p<0.001
  • Home BP was significantly reduced in the beetroot juice group compared to the placebo group (Beetroot juice minus Placebo: SBP 8.1 mmHg, DBP 3.8 mmHg)
  • Markers of endothelial function and arterial stiffness were also significantly improved in the beetroot juice group when compared to placebo
  • There was no evidence of methemoglobinemia or tachyphylaxis (sudden loss of effect) in the beetroot juice group
  • Discoloration of the urine and feces was common (known side effect of beets)

Findings: These findings suggest a role for dietary nitrate as an affordable, readily-available, adjunctive treatment in the management of patients with hypertension


SODIUM/SALT AND HYPERTENSION













BIBLIOGRAPHY