Hypertension: Diagnosis and Impact

Hypertension Overview

• Hypertension (HTN) is elevated blood pressure (BP), a serious medical condition increasing risks of heart, brain, kidney, and other diseases.
• Worldwide, it's the most common primary diagnosis.
• Over 1 billion people globally have HTN, many in low- and middle-income countries.
• HTN is a major cause of premature death.

Defining Hypertension

• Sustained elevation of systemic arterial blood pressure.
• Systolic BP (SBP) ≥140 mmHg and/or diastolic BP (DBP) ≥90 mmHg.
• Average of two or more properly measured, seated BP readings taken on two or more office visits.
• At least two measurements should be recorded and averaged.

Accurate BP Measurement

• Equipment should be regularly inspected and validated.
• Measuring operator should be trained and retrained.
• Patients should be properly prepared (seated quietly for at least 5 minutes), and caffeine, exercise, and smoking should be avoided for 30 minutes before measurement.
• Appropriate-sized cuff should be used.
• Auscultatory method should be employed.

Classification of Hypertension in Adults

• A table categorizing hypertension in adults by systolic and diastolic blood pressure levels and accompanying recommendations for follow-up is presented.

Prehypertension

• SBP >120 mmHg and <140 mmHg and/or DBP >80 mmHg and <90 mmHg.
• Prehypertension is not a disease, but a high-risk designation for developing hypertension.
• Prehypertensive patients aren't typically treated with medications but advised to modify their lifestyle.
• Drug therapy indicated if lifestyle changes fail to reduce BP to ≤130/80.

Isolated Systolic Hypertension

• Isolated systolic hypertension isn't treated differently than other hypertension cases.
• Systolic BP more crucial after age 50, while diastolic BP is more important before age 50.
• Primary concern during treatment is systolic blood pressure.

Hypertension Crises

• Hypertensive Urgencies: No progressive target-organ dysfunction.
• Hypertensive Emergencies: Progressive end-organ dysfunction (often called malignant hypertension).

Hypertension Urgencies

• Severe elevation of BP in the upper range of stage II hypertension.
• Without progressive end-organ dysfunction.
• Examples: severe headache, shortness of breath, or chest pain. Usually due to poorly controlled HTN.

Hypertension Emergencies

• Severely elevated BP (>180/120 mmHg).
• With progressive target organ dysfunction.
• Require emergent lowering of BP.
• Examples: hypertensive encephalopathy, acute LV failure with pulmonary edema, acute MI, or unstable angina pectoris, dissecting aortic aneurysm.

Types of Hypertension

• Primary (Essential): Accounts for ~95% of cases--no known, universally established cause.
• Secondary: Lesser prevalent; caused by other potentially treatable conditions.

Causes of Secondary Hypertension:

• Common: Intrinsic renal disease, renovascular disease, mineralocorticoid excess, and sleep breathing disorders.
• Uncommon: Pheochromocytoma, glucocorticoid excess, coarctation of the aorta, hyper/hypothyroidism.

Secondary Hypertension Clues: History & Physical Examination

• Patient onset of HTN <30 or >55 years.
• Episodic headache, chest pain, palpitation.
• Obesity/history of snoring/sleepiness.
• Pallor, edema, abdominal bruit, truncal obesity, purple striae, buffalo hump.
• All relevant details include severity.

Secondary Hypertension Clues: Routine Laboratory Tests

• Increased creatinine, abnormal urinalysis.
• Unexplained hypokalemia, impaired blood glucose, and impaired thyroid function tests (TFTs).

Secondary Hypertension: Screening Tests

• Estimated GFR, CT angiography
• Dexamethasone suppression test, drug screening.
• 24-hour urinary metanephrine and normetanephrine.
• 24-hour urinary aldosterone, mineralocorticoid measurements, Doppler flow study, magnetic resonance angiography.
• Sleep study, thyroid stimulating hormone (TSH), parathyroid hormone (PTH).

Renal Parenchymal Disease

• Renal disease is the second most prevalent causative factor of secondary HTN.
• Multifactorial causes: imbalances in Na/water balance, vasodepressors/prostaglandins.
• Etiologies vary from atherosclerosis (more common in elderly) to fibromuscular dysplasia (more common in younger patients, esp. females).

RenoVascular Hypertension

• Atherosclerosis is the most common cause (~75-90% of cases).
• Fibromuscular dysplasia is another significant contributing factor (10-25%).
• Other contributing conditions include aortic/renal dissection, Takayasu's arteritis, thrombotic/cholesterol emboli, post-transplantation stenosis, and post-radiation.

Complications of Prolonged Uncontrolled HTN

• Changes in blood vessel walls leading to arteriosclerosis throughout the vasculature.
• Target organ dysfunction and failure.
• Fundoscopic evidence of blood vessel damage.

Effects of HTN on Target Organs

• Cardiovascular system—ventricular hypertrophy, dysfunction, and failure, arrhythmias, coronary artery disease, acute myocardial infarction (MI), arterial aneurysms, and dissection.
• Kidneys—glomerular sclerosis, impaired kidney function, ending in kidney disease, and specifically ischemic kidney disease (often linked with renal artery stenosis).
• Nervous system—stroke, intracerebral and subarachnoid hemorrhages, cerebral atrophy, and dementia.
• Eyes—retinopathy, retinal hemorrhages, impaired vision, vitreous hemorrhage, retinal detachment, neuropathy that compromises extraocular muscle function.

Hypertension Management: Patient Evaluation Objectives

• Evaluate lifestyle and concurrent cardiovascular risk factors/disorders impacting prognosis & treatment planning.
• Determine identifiable causes of elevated BP.
• Assess presence/absence of target organ damage and cardiovascular disease (CVD).

Hypertension Management: Cardiovascular Risk Factors

• Hypertension
• Cigarette smoking
• Obesity (BMI ≥30 kg/m²)
• Physical inactivity
• Dyslipidemia
• Diabetes mellitus
• Microalbuminuria (or estimated GFR <60 mL/min)
• Age (≥55 for men, ≥65 for women)
• Family history of premature CVD (<55 for men, <65 for women).

Hypertension Management: Identifiable Causes

• Sleep apnea
• Drug-induced or related causes
• Chronic kidney disease
• Primary aldosteronism
• Renovascular disease
• Chronic steroid therapy/Cushing's syndrome.
• Pheochromocytoma
• Coarctation of the aorta
• Thyroid or parathyroid disease

Hypertension Management: Target Organ Damage

• Heart: Left ventricular hypertrophy, angina, prior myocardial infarction (MI), prior coronary revascularization, heart failure.
• Brain—stroke, transient ischemic attack.
• Kidneys—chronic kidney disease.
• Peripheral artery disease.
• Retinopathy.

Hypertension Management: History

• Angina/myocardial infarction (MI)
• Stroke.
• Past history of hypertension.
• Premature death from hypertension.
• Diabetes.
• Smoking status.
• Excessive alcohol intake.
• High salt intake.
• Family history of HTN, diabetes, and premature death.

Hypertension Management: History (continued)

• Use of steroids or NSAIDs.
• Medications (e.g., diuretics).
• Other medical conditions, including DM, Asthma, COPD. Relevant information includes presence of polyuria, nocturia, and symptoms impacting mobility.

Hypertension Management: Examination

• Appropriate BP measurement in both arms.
• Calculation of BMI, especially for abdominal and femoral bruits.
• Physical exam of the thyroid, heart, lungs, abdomen (looking for enlarged kidneys or masses), and lower extremities for edema.
• Neurological system assessment.
• Optic fundus examination/retinopathy analysis.

Hypertension Management: Investigations

• Urinalysis (blood, protein, glucose).
• Full blood count (hematocrit, blood glucose, urea, creatinine, potassium, calcium).
• Lipid profile (total cholesterol, HDL, LDL, and triglycerides).
• Thyroid function tests.
• ECG & echocardiography (in certain cases).
• Optional tests: LVH & CAD, urinary albumin-to-creatinine ratio.

Hypertension Treatment: Goals

• Reduce BP to target levels to reduce cardiovascular risk.
• Target BP levels tailored to individual patient characteristics and comorbidities.
• <140/90 mmHg is the general target; lower goal (<130/80 mmHg) for patients with diabetes or renal disease.

Hypertension Treatment: Benefits

• Reductions in stroke are about 35-40%.
• Reductions in MI incidence are about 20-25%.
• Reductions in heart failure risk are typically above 50%.

Hypertension Treatment: Lifestyle Modifications

• Healthy diet rich in fruits, vegetables, whole grains, and lean proteins, low in saturated fats, cholesterol, and sodium.
• Regular physical activity (e.g., brisk walking, cycling, swimming).
• Weight management.
• Limit alcohol and caffeine intake.
• Managing conditions like diabetes.

Hypertension Treatment: Lifestyle Modifications

• Managing conditions like diabetes—control glucose and lipids.
• Controlling blood glucose and lipid levels.
• Moderate or vigorous physical activity of 30 to 40 minutes, three to four times a week.
• Reducing sodium intake (below 2400 mg/day).
• Healthy diet (including fruits, vegetables, whole grains, and lean proteins, and limiting intake of saturated and total fats).

Hypertension Treatment: Medications

• Pharmacotherapy is often necessary to achieve target BP.
• Medication selection should be individualized based on patient factors like age, comorbidities, and drug interactions.

Hypertension Treatment: Medications - Classes

• Angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs).
• Beta-blockers.
• Calcium channel blockers.
• Diuretics (thiazide or thiazide-like).

Hypertension Treatment: Combination Therapy

• In many cases, combining two or more antihypertensive medications is necessary to achieve optimal control.
• Combination therapies that combine drugs from different classes, often with synergistic effects that minimize side effects, are common.

Hypertension Treatment: Antihypertensive Drug Combinations-Algorithm

• JNC 7 & 8 guideline algorithms are detailed, showing stages of hypertension treatment based on patient age, comorbidities, and BP levels.

Hypertension Conclusions

• Hypertension is a prevalent and complex condition requiring a comprehensive approach to optimize patient outcomes through regular monitoring and adherence to treatment plans.
• Interprofessional collaborations between clinicians are essential for appropriate care.

Test your knowledge of hypertension's global impact, diagnosis criteria, and management. This quiz includes questions about blood pressure readings, patient education, and ensuring accurate blood pressure measurements in clinical settings. Evaluate understanding of hypertension classification and appropriate follow-up recommendations.