Kembara Xtra - Medicine - Secondary and Resistant Hypertension

Kembara Xtra - Medicine - Secondary and Resistant Hypertension 
Those who have uncontrolled hypertension (HTN) include:
Resistant HTN is characterized as blood pressure (BP) that remains above target despite the use of three antihypertensive medications simultaneously from various classes. One of the three medications should ideally be a diuretic, and other medications should be prescribed at the right doses. Despite being typical mimics, the "white-coat effect" and drug nonadherence should not be included in the diagnosis.
Secondary HTN: high BP brought on by a discernible underlying cause
The 2017 ACC/AHA guideline revision advises changing how HTN is categorised. Systolic blood pressure (SBP) 140 mm Hg or diastolic blood pressure (DBP) 90 mm Hg are considered stage 2 HTN for the purposes of this chapter. The recommendation is somewhat debatable (1). The topic "Hypertension, Essential" is discussed here.
Many medical professionals continue to follow the JNC 8 recommendation, which calls for a target blood pressure of 150/90 mm Hg for patients older than 60 years old and rejects the classification of HTN for values lower than 140/90.


Aspects of Geriatrics
Secondary HTN is strongly predicted by the age at which HTN first appears in persons older than 60.
In patients over 80, a higher goal SBP of 150 mm Hg should be taken into account. To prevent excessive diastolic dropping, exercise caution.
Systolic HTN is particularly problematic in the elderly, who may also be more susceptible to diuretics and dihydropyridine calcium channel blockers.
Sleep apnea, renal illness, atherosclerotic renal artery stenosis, and primary aldosteronism (PA) are secondary reasons that are more prevalent in the elderly.
Noncompressible arteries (Osler phenomenon) are more common in older people with aortic stenosis. At high cuff pressures, brachial and radial artery pulsations are noticeable.

Caution 
Pseudoresistance: Patient not at rest; not sitting quietly for five minutes; inaccurate blood pressure reading; too-small cuff.
Poor adherence: It's been estimated that 40–60% of HTN patients have this in primary care settings.
White coat effect: 20–40% occurrence. Never base clinical decisions about HTN exclusively on measurements taken in a clinic environment. It is more dependable to use ABPM or home BP monitoring. Consult the AHA and USPSTF recommendations.
– The preferred technique for taking blood pressure is automated office blood pressure, or AOBP. When deciding on a course of treatment, home blood pressure measurement (HBPM) is suggested if AOBP is not feasible.
Insufficient care

Epidemiology 

 Predominant age: HTN often develops between the ages of 30 and 50. The combined consequences of death, myocardial infarction, congestive heart failure (CHF), stroke, or chronic renal disease are more common in patients with resistant HTN. The age of onset can change depending on the etiology. The chance of a secondary etiology for HTN increases with age of onset 20 or >50 years.

● Age (>75 years), the presence of left ventricular hypertrophy (LVH), obesity (BMI >30), and high baseline SBP are the best indicators of resistant HTN. Other risk factors include having diabetes, having chronic kidney disease, living in the Southeast of the United States, being an African American (particularly a woman), and consuming too much salt.
Incidence
In the United Kingdom, the age-standardized incidence in 2015 was 0.4 cases per 100 person-years. The clarity of information is lower in the United States.

Prevalence

According to data from clinics, the prevalence of resistant HTN is between 10 and 15 percent (5). According to NHANES research, just 53% of individuals had their blood pressure kept under 140/90 mm Hg.
The most frequent cause of hypertension that appears to be resistant to treatment is probably failure to take prescribed medications as directed.

Pathophysiology and Etiology 

Obstructive sleep apnea (25 to 50 percent): Interventions have produced a range of results.
8–20% of resistant HTN cases have primary hyperaldosteronism.
1–2% of hypertensives have chronic renal illness.
Renovascular disease (0.1-0.7%), which affects up to 35% of older people and 20% of people having a cardiac catheterization
Cushing disease (0.1%)
0.04-0.1% of hypertensives have pheochromocytoma.

Other uncommon reasons include aortic coarctation, hyperparathyroidism, hyperthyroidism, and brain tumors.
Drug-related causes include prescription drugs, particularly NSAIDs (which may also reduce the effectiveness of ACE inhibitors), decongestants, stimulants (such as amphetamines and ADHD medications), anorectic substances (such as modafinil, ephedra, guarana, ma huang, and bitter orange), erythropoietin, natural licorice (found in some chewing tobacco), yohimbine, and glu
- Oral contraceptives (OCP): Due mostly to the estrogen content, women who use oral contraceptives may experience more severe HTN and poorer BP control. The BP may return to normal when OCP is stopped. Estrogen after menopause does not seem to correlate as significantly.
- Cocaine, amphetamines, and other illegal drugs; withdrawal symptoms from alcohol and drugs

 Lifestyle variables: Dietary salt and obesity may counteract the curative effects of diuretics. Alcohol abuse may contribute to or worsen HTN. The lack of exercise also plays a role.
Genetics Heritable and more common in some families, BP has a genetic basis. Although genetic variations have been found in people with resistant HTN, they are only thought to contribute about 3% of the variance in BP.


Risk Elements 

According to a large cohort research, male, Caucasian, older, and diabetic individuals were more likely to have resistant HTN (16.2%). In addition, compared to other drug classes, they were more likely to be taking -blockers, calcium channel blockers, and -adrenergic blockers. Obesity, diabetes, worsening of control in previously stable hypertensive patients, onset in patients younger than 20 or older than 50, the absence of a family history of the disease, significant damage to target end organs, stage 2 HTN (SBP >160 mm Hg or DBP >100 mm Hg), renal disease, and drug or alcohol use are risk factors for resistant or secondary HTN.
DURATIONAL PREVENTION
It is believed that main or essential HTN can be prevented in the same ways as resistant and secondary HTN: It may be advantageous to follow the Dietary Approaches to Stop Hypertension (DASH) diet, eat less sodium, exercise, cut back on alcohol use, and stop smoking. Techniques for relaxation may be beneficial, although the evidence is sparse.

Accompanying Conditions 
problems of sleep; obesity

History 
Request or evaluate at each visit: SANS acronym: (i) Consuming salt; (ii) Consuming alcohol; (iii) Using NSAIDs; and (iv) Sleeping (author's recommendation based on references provided). (1)
Inquire about your drug compliance. According to estimates, 20% of HTN patients adhere to their treatment regimens well enough to see a clinical effect in the first year of their treatment.

Review your home BP readings and think about using an ambulatory BP ABMP.
The etiology of secondary HTN will affect the history.
- OSA: daytime somnolence and loud snoring during sleeping
- Pheochromocytoma: headache, palpitations, and sweating attacks
Cushing syndrome symptoms include weight gain, weakness, bruising easily, and amenorrhea. Increased intravascular volume symptoms include edema.


clinical assessment 

Make sure the blood pressure is accurately measured. Prior to measurement, the patient should sit quietly with their backs supported for at least five minutes. A bladder that covers at least 80% of the arm is the ideal cuff size. Keep your arm at chest height. at least two readings, separated by at least one minute.
Take the BP in both arms. For orthostasis, also assess standing blood pressure.

● The USPSTF advises "obtaining measurements outside of the clinical setting for diagnostic confirmation."
Pay attention to information about potential etiologies:
For renovascular hypertension, listen for systolic/diastolic abdominal bruit; for pheochromocytoma, listen for diaphoresis and tachycardia; for Cushing syndrome, listen for hirsutism, moon facies, dorsal hump, purple striae, and truncal obesity; for thyroid disease, listen for enlarged thyroid, tremor, exophthalmos, and 

Diagnosis Differential Pseudoresistance

Laboratory Results 
An initial workup ECG was performed; LVH is a key indicator of resistant HTN.
If your history and physical indicate it, a sleep study. It is advised to use the Epworth Sleepiness Scale.
It has been demonstrated that home-based polysomnography is reliable for detecting OSA. A night of oximetry is useless.
Initial examinations (lab, imaging)
Urinalysis, CBC, potassium, sodium, glucose, creatinine, lipids, thyroid-stimulating hormone (TSH), and calcium should be part of the initial restricted diagnostic tests. In 50% of people with hyperaldosteronism, potassium levels may be normal.
Imaging tests are only required if history, physical exam, or lab results suggest it.
If renal illness is suspected, abdominal ultrasound
It's possible that duplex ultrasonography will be the test of choice for renovascular disease. Although sensitive, MR angiography (MRA) of the renal vasculature is less specific and may perhaps be more damaging. To confirm the diagnosis, conventional catheter angiography or CT angiography may be needed.
In this era of numerous CT examinations, adrenal "incidentalomas" regularly develop. If resistant HTN is evident, hyperaldosteronism or hyperadrenal corticoid states should be taken into consideration.

Tests in the Future & Special Considerations

PA testing may be done in the future.
Spironolactone or eplerenone, an aldosterone antagonist that is less estrogenic than spironolactone, may be more clinically relevant and preferable for empiric treatment.
Amiloride might be a possibility for potassium sparing, however it hasn't been proven to have an impact on the level of aldosterone.
The ideal laboratory test is the plasma aldosterone-to-renin ratio (ARR), although it is challenging to do and accurately interpret. Consult your reference lab and use caution when interpreting data.
– Pheochromocytoma screening (further testing):
Metanephrines in plasma
– Other tests to take into account for secondary or resistant HTN include:
24-hour urine testing for free cortisol, calcium, and parathyroid hormone (PTH), a suppression test with 1-mg dexamethasone overnight, and a toxicology urine screen
Other/Diagnostic Procedures
ABM should be taken into consideration, especially if the white coat effect is thought to be present. Results from a home blood pressure monitor are more accurate at forecasting death, stroke, and other target organ damage. The ideal protocol calls for morning and evening measurements in pairs, each lasting four to seven days.
Oscillometric, electronic, upper arm, memory-equipped device: average readings from various days' worth of time

Management The etiology of HTN determines the treatment approach. For details on how to treat each given etiology, please go to that entry.
The National Institute for Health Care and Excellence (5) provides a helpful management strategy that emphasizes lifestyle adjustment, including nutrition, less sodium intake, exercise, and moderate alcohol consumption.
Place a focus on following JNC 8 and/or AHA/ACC recommendations, with a focus on modifying one's lifestyle.
– Patients who are obese and the elderly may respond to diuretics especially well.
– Diuretic tolerance may develop as a result of long-term thiazide adaptation or the "braking effect." Think about raising the thiazide dosage or incorporating an aldosterone inhibitor.


 Specific treatment for some secondary etiologies
Aldosterone receptor antagonists include eplerenone or spironolactone (the latter has a reduced estrogenic impact).
- Aldosterone receptor antagonist for Cushing syndrome
- OSA: oxygen, surgery, continuous positive airway pressure (CPAP), and weight reduction
In some patients, mandibular advancement devices may be similarly successful.
- Nighttime hypoxia: oxygen administration
– Renal sympathetic denervation is a contentious procedure since existing methods have mostly fallen short of proving a therapeutic advantage. A recent trial on renal denervation using a catheter revealed a slight reduction in SBP, but bigger studies are required to assess the total benefit.

Atherosclerotic renal artery stenosis (ARAS) treatment is debatable. A recent meta-analysis doubts percutaneous stenting's utility once more. ACEi and ARB medicines may reduce mortality over the long term.


Medication 

Adhere to the treatment recommendations and algorithms provided by JNC 8 and AHA/ACC/CDC while being aware of their distinctions.

 Increasing the dose of existing drugs may not always be more effective (see JNC 8 management algorithm option B).

Nondiuretic drugs taken at night may be more effective and have less negative effects on HTN.
Aldosterone antagonists are frequently effective when used orally.
Although central-acting medications like clonidine are successful in lowering blood pressure, there aren't many data on their effects.

Caution 

Instances where end-organ damage can be prevented or limited by an immediate BP lowering should be treated with HTN-specific agents.
The CORAL research found that renal artery stenting did not enhance outcomes over medical therapy alone in individuals with atherosclerotic renovascular disease and HTN. Angioplasty is the preferred treatment for fibromuscular dysplasia of a renal artery.
Retrospective studies show that patients with resistant HTN who are referred to specialized HTN clinics have better control rates.


First-line treatments for non-black people include CCB, ACEi, or ARB (but not both).
Thiazide diuretics and CCBs are recommended for black patients. Options include hydralazine and isosorbide mononitrate or dinitrate. Note: Recently, race-based prescription has come under scrutiny. However, ACEi or ARB medicines may not work for people of African origin.
Next Line
Add a K+-sparing diuretic or combine thiazide diuretics with ACEi, ARB, or CCB. -Blockers may be indicated, especially if there is a strong medical reason, such as CHF or ischemic heart disease, as well as migraines and tachyarrhythmias.
Fourth Line
If the second line's additional medication does not sufficiently drop blood pressure, work up for secondary reasons (chronic NSAID usage, alcohol abuse, RAS, etc.) should be started.

Referral 
Consider referring the patient to a hypertension center or nephrology if management is ineffective. If a secondary cause is found, contact the relevant specialization.

Further Treatment 
Other than the usual lifestyle changes, non-drug therapies may be beneficial.

Various Therapies 
An great handout and patient information are available from the University of Wisconsin Integrative Medicine program.

Admission 
Immediate general measures for hypertension

Constant Care 
Encourage 30 minutes of aerobic exercise every day, depending on the patient's health.

Diet: Suggest the DASH diet or the Mediterranean diet. Reduced salt intake may lower blood pressure in some patients.

Patient Education: Home blood pressure monitoring is advised.