Hypertension and Blood Pressure Classification

Hypertension (HTN)

• Hypertension is persistently elevated arterial blood pressure (BP).
• Isolated systolic hypertension involves DBP values <90 mm Hg and SBP values ≥140 mm Hg.
• Hypertensive crisis is BP >180/120 mm Hg.
  • Hypertensive emergency involves extreme BP elevation with acute or progressing end-organ damage.
  • Hypertensive urgency involves high BP elevation without acute or progressing end-organ injury.

Classification of Blood Pressure in Adults (Age 18 and Older)

• Normal: Systolic BP <120 mm Hg and Diastolic BP <80 mm Hg
• Elevated: Systolic BP 120-129 mm Hg and Diastolic BP <80 mm Hg
• Stage 1 Hypertension: Systolic BP 130-139 mm Hg or Diastolic BP 80-89 mm Hg
• Stage 2 Hypertension: Systolic BP ≥140 mm Hg or Diastolic BP ≥90 mm Hg

Pathophysiology of Hypertension

• Primary (essential) hypertension accounts for 90% of cases.
  • It is often secondary to underlying issues like:
    • Humoral abnormalities
    • Central nervous system (CNS) abnormalities
    • Renal or tissue abnormalities
    • Vasodilating substances deficiency
    • Excess vasoconstricting substances
    • High sodium intake or lack of dietary calcium
• Secondary hypertension contributes to <10% of cases and can be caused by:
  • Chronic kidney disease (CKD) or renovascular disease
  • Cushing's syndrome
  • Coarctation of the aorta
  • Obstructive sleep apnea
  • Hyperparathyroidism
  • Pheochromocytoma
  • Primary aldosteronism
  • Hyperthyroidism
  • Drugs (e.g., corticosteroids, estrogens, NSAIDs, amphetamines, sibutramine, cyclosporine, tacrolimus, erythropoietin, venlafaxine)

Clinical Presentation of Hypertension

• Primary HTN is usually asymptomatic initially.
• Secondary HTN may manifest symptoms of the underlying disorder, such as:
  • Pheochromocytoma: headaches, sweating, tachycardia, palpitations, and orthostatic hypotension.
  • Primary aldosteronism: hypokalemic symptoms of muscle cramps and weakness.
  • Cushing's syndrome: weight gain, polyuria, edema, menstrual irregularities, recurrent acne, or muscular weakness in addition to classic features (moon face, buffalo hump, and hirsutism).

Diagnosis of Hypertension

• Diagnosis relies on the average of two or more BP readings taken at two or more clinical encounters.
• Physical exam to assess for signs of end-organ damage (eye, brain, heart, kidneys, and peripheral blood vessels).
• Funduscopic examination: look for arteriolar narrowing, focal arteriolar constrictions, arteriovenous nicking, retinal hemorrhages and exudates, and disk edema. -Papilledema often indicates hypertensive emergency.
• Consider ambulatory/home blood pressure monitoring.
• Laboratory tests like BUN, creatinine, lipid panel, glucose, electrolytes, hemoglobin, hematocrit, spot urine albumin-to-creatinine ratio, and estimated GFR are helpful in evaluating for secondary causes of hypertension. -Tests for secondary hypertension: plasma norepinephrine/urinary metanephrines, plasma and urine aldosterone, plasma renin activity, captopril stimulation test, and renal vein/renal artery angiography.

Risk Factors for Hypertension

• Age (≥55 yrs in men, ≥65 yrs in women)
• Diabetes (type 1 or 2)
• Dyslipidemia
• Albuminuria
• Family History of premature cardiovascular (CV) disease
• Overweight (BMI 25-29.9 kg/m²) or obesity (BMI ≥30 kg/m²)
• Physical inactivity
• Tobacco use

Treatment Goals for Hypertension

• Reduce morbidity and mortality by the least intrusive means possible.
• Target BP goal range, based on individual risk factors and specifics.
• Use appropriate and specific anti-hypertensive agents based on evidence (compelling indications and efficacy).

Benefits of Treating High Blood Pressure

• Forty-percent decrease in stroke
• Twenty-five-percent decrease in Myocardial Infarction (MI)
• Fifty-percent decrease in Heart Failure (HF)

Desired Outcomes for Chronic HTN Treatment

• Most patients (including those with clinical ASCVD, diabetes, and CKD) should have a target BP of <130/80 mmHg.
• Older ambulatory/community-dwelling patients should aim for SBP of <130 mmHg.
• For institutionalized older patients or those with high disease burden/limites life expectancy, Consider a relaxed SBP goal of at least <150 mmHg or <140 mmHg if tolerable.

Non-Pharmacological Therapy for Hypertension

• Weight loss
• DASH (Dietary Approaches to Stop Hypertension) eating plan
• Dietary sodium restriction (ideally to 1.5 g/day)
• Regular aerobic physical activity
• Moderation of alcohol consumption
• Smoking cessation

Lifestyle Modifications for Hypertension (Approximate SBP reduction, With/Without Hypertension)

• Weight loss: Aim for normal BMI (18.5-24.9 kg/m^2) or at least 1 kg weight loss (5mm Hg/1kg loss)
• DASH-type dietary patterns: Consume fruits, vegetables, and low-fat dairy with reduced saturated and total fat (11 mm Hg with, 3mm Hg without)
• Reduced salt intake: Ideally reduce daily sodium intake to 1.5 g/day (5-6 mm Hg with, 2-3 mm Hg without)
• Physical activity (aerobic/dynamic): Perform 90-150 min/week involving moderate-to-vigorous intensity aerobic or dynamically resistance training (5-8 aerobic/dynamic with, 2-4 aerobic/dynamic without)
• Moderation of alcohol intake: Men ≤2 drinks/day; Women ≤1 drink/day (3 mm Hg with, or without change)

Pharmacological Therapy for Hypertension

• Initial drug selection depends on the degree of BP elevation, and compelling indications.
  • ACE inhibitors, ARBs, CCBs, and thiazide diuretics are acceptable first-line options.
• B-blockers; treat specific compelling indications.
• Combination therapy with a first-line antihypertensive agent when indicated.

Pharmacological Therapy by Stage

• Stage 1 (Preferable): Combination therapy(initial) or a first-line agent.
• Stage 2 (Preferable): Two (2) first line agents in combination therapy.
• Other classes of antihypertensives can be used (table 10.3).

Algorithm for Hypertension Treatment

• The algorithm outlines a stepwise approach to managing hypertension based on BP stages and compelling indications.

Compelling Indications for Pharmacotherapy (Additional information)

(A table that lists specific conditions for which certain drugs are first-line treatment choices will be presented elsewhere).

Angiotensin-converting enzyme inhibitors

• First-line option or second most frequent,
• Block angiotensin I to angiotensin II (potent vasoconstrictor).
• Stimulates aldosterone release.
• Has potential to block degradation of bradykinin, thus having vasodilatory effects
• Start low and go slow to avoid acute hypotension

Side Effects of ACE Inhibitors

• Decrease aldosterone, ↑ serum potassium, particularly in CKD patients
• Increased serum creatinine
• Rare acute renal failure, commonly in pre-existing kidney disease
• Angioedema (rare), dry cough (up to 20%), contraindicated during pregnancy

Angiotensin II Receptor Blockers (ARBs)

• First-line, similar to ACE inhibitors
• Block angiotensin II, Type 1 receptor.
• No effect on bradykinin breakdown, thus less effective in some cases as an anti-hypertensive.

Calcium Channel Blockers (CCBs)

• First-line therapy options, especially for CAD and diabetes.
• Cause relaxation of cardiac and smooth muscle.
• Vasodilation of blood vessels and reduced BP.
• Dihydropyridine CCBs, may cause reflex sympathetic activation requiring slow release to avert adverse effects
• Negative inotropic effects in most and lack thereof in some.
• Possible side effects to be aware of

Diuretics

• Thiazides: preferred first-line and combination therapy.
• Loop diuretics: Potent but not ideal for general antihypertensive use, except if edema is present.
• Potassium-sparing diuretics: Counteract potassium-wasting effects (weak) of other agents. These are aldosterone antagonists, thus requiring a prolonged waiting period(up to 6 weeks) to take effect.

Beta-Blockers

• First-line in specific conditions.
• Hypotensive effects via decreased cardiac output and negative chronotropic and inotropic effects on the heart. Block renin release from the kidney.
• Atenolol, betaxolol, bisoprolol, metoprolol and nebivolol, better for patients with asthma or COPD, are better options for such cases.
• Avoid abrupt cessation in patients with CAD

Direct Arterial Vasodilators

• Hydralazine vs. minoxidil: potency and effects diminish over time, not for long-term use. May not be necessary if patients initially get treatment with B-blockers and diuretics.

Direct Renin Inhibitor (Aliskiren)

• Renin antagonist
• Contraindicated in pregnancy; diabetic patients (Renal impairment, hyperkalemia, hypotension risk)
• Combination with ACEi or ARBs avoid if renal impairment is present (CrCl <60 mL/min.)
• Avoid usage with itraconazole or cyclosporine.

American Society of Hypertension Recommendations: Combination Therapy

• Preferred combination therapies
• Acceptable combination therapies
• Less effective combination therapies

Considerations with specific antihypertensive agents

• Patients with ischemic heart disease avoid potent vasodilators.
• Elderly patients should avoid agents associated with orthostatic hypotension and start with lower doses.

Resistant Hypertension

• Improper BP Measurement: Excess sodium intake, Volume retention from kidney disease, Inadequate diuretic therapy.
• Drug-induced or other causes: Nonadherence, Inadequate doses, Agents listed.
• Associated conditions: Obesity, Excess alcohol intake, Obstructive sleep apnea.
• Secondary hypertension

Monitoring Hypertension Treatment

• Patients returned in 4 weeks to assess treatment efficacy.

Hypertensive Urgency and Emergency

• Definitions
  • Hypertensive Urgency: Acutely elevated BP, especially diastolic ≥120-130 mmHg, without target organ damage.
  • Hypertensive Emergency: Hypertension with evidence of target organ damage.
  • Target organ damage includes: brain, heart, kidneys, eyes (e.g., encephalopathy, hemorrhage, MI, acute heart failure, acute kidney failure, aortic dissection, or eclampsia)
• Goals
  • Urgency: Lower mean arterial pressure to goal or near goal within 24 hours via oral medications.
  • Emergency: Lower mean arterial pressure by 25% or diastolic pressure. to goal within 30-60 minutes.

Patient Care Process for Hypertension Management

• The patient-centered approach to management of hypertension includes following steps:
  • Collect: Information from the patient (medical history, social factors)
  • Assess: Patient's status (vital signs)
  • Communicate/Collaborate: Discuss with the patient about the treatment
  • Document: Record all assessments, interventions, and progress.
  • Plan: Create an appropriate treatment plan, and monitor its efficacy
  • Implement: Follow the outlined treatment plan
  • Follow-up: Ongoing monitoring, and re-evaluation

Test your knowledge on hypertension, including its definitions, classifications, and underlying causes. This quiz covers important concepts related to blood pressure levels and the pathophysiology of hypertension.