What are the recommendations for managing a patient according to the International Society of Hypertension (ISH) guideline (ISHP)?

International Society of Hypertension (ISH) Guidelines for Hypertension Management

The 2020 ISH guidelines recommend targeting blood pressure <130/80 mmHg for most adults through a stepwise approach starting with lifestyle modifications and progressing to combination pharmacotherapy, with specific algorithms based on patient demographics and comorbidity status. 1, 2

Diagnosis and Blood Pressure Measurement

• Diagnose hypertension when office BP measurements are consistently ≥140/90 mmHg 2
• Use validated automated upper arm cuff devices with appropriate cuff size, averaging multiple readings 2
• Measure BP in both arms simultaneously at first visit; use the arm with higher readings for subsequent measurements 2
• Confirm elevated office BP (≥130/85 mmHg) with home BP monitoring (target <135/85 mmHg) or 24-hour ambulatory monitoring (target <130/80 mmHg) 2

Treatment Initiation Strategy

For Grade 1 Hypertension (140-159/90-99 mmHg):

• Start drug treatment immediately in high-risk patients (those with CVD, CKD, diabetes, organ damage, or aged 50-80 years) 2
• For low-moderate risk patients, trial lifestyle modifications for 3-6 months before medications if BP remains elevated 2

For Grade 2 Hypertension (≥160/100 mmHg):

• Start both lifestyle interventions and drug treatment immediately for all patients 2

Pharmacological Treatment Algorithm

For Non-Black Patients: 2

1. Start with low-dose ACE inhibitor or ARB
2. Increase to full dose
3. Add thiazide/thiazide-like diuretic
4. Add spironolactone (if K+ <4.5 mmol/L and eGFR >45 ml/min/1.73m²) or alternatives (amiloride, doxazosin, eplerenone, clonidine, beta-blocker) 1, 2

For Black Patients: 2

• Start with low-dose ARB plus DHP-CCB, or DHP-CCB plus thiazide/thiazide-like diuretic

Key Pharmacological Considerations:

• Replace hydrochlorothiazide with chlorthalidone for resistant hypertension (provides greater 24-hour BP reduction) 2
• Use thiazide-like diuretics rather than thiazides 1
• Initiate loop diuretics for eGFR <30 ml/min/1.73m² or clinical volume overload 1
• Simplify regimens with once-daily dosing and single-pill combinations 2
• Consider taking at least one medication at bedtime for improved 24-hour control 2

Target Blood Pressure Goals

• Aim for BP <130/80 mmHg for most adults 2
• Minimum reduction of at least 20/10 mmHg 2
• Achieve target within 3 months of treatment initiation 2
• For elderly patients (>80 years) or frail individuals, individualize targets based on frailty status 2, 3

Resistant Hypertension Management

Definition: BP >140/90 mmHg despite three or more antihypertensive medications at optimal doses including a diuretic 1

Stepwise Approach: 1

1. First, exclude pseudoresistance: poor BP measurement technique, white coat effect, medication nonadherence, suboptimal drug choices
2. Second, exclude substance-induced hypertension: NSAIDs, decongestants, stimulants, alcohol
3. Third, screen for secondary causes (see below)
4. Optimize current regimen: maximize diuretic therapy, ensure thiazide-like rather than thiazide diuretics
5. Add spironolactone as 4th-line agent (if K+ <4.5 mmol/L and eGFR >45 ml/min/1.73m²) 1
6. Refer to specialist centers with expertise in resistant hypertension 1

Secondary Hypertension Screening

Screen for secondary causes in: 1

• Early onset hypertension (<30 years) without risk factors (obesity, metabolic syndrome, family history)
• Resistant hypertension
• Sudden deterioration in BP control
• Hypertensive urgency/emergency
• Strong clinical clues suggesting secondary etiology

Basic Screening Includes: 1

• Thorough history and physical examination
• Basic blood biochemistry: serum sodium, potassium, eGFR, TSH
• Dipstick urinalysis

Most Common Secondary Causes: 1

• Renal parenchymal disease
• Renovascular hypertension
• Primary aldosteronism
• Chronic sleep apnea
• Substance/drug-induced hypertension

Further Diagnostic Tests (when indicated): 1

• Kidney ultrasound
• Adrenal imaging (CT)
• Renal artery imaging (duplex ultrasound, CT/MR angiography)
• Confirmatory testing for primary aldosteronism (saline suppression test, adrenal vein sampling)
• Sleep studies for obstructive sleep apnea
• Dexamethasone suppression tests and 24-hour urinary free cortisol for Cushing syndrome

Monitoring and Follow-up

• Check serum electrolytes and renal function within 1 month of adding or increasing diuretics or ACE inhibitors 2
• Monitor for adverse effects, particularly electrolyte abnormalities with diuretics 2
• Assess for orthostatic hypotension, especially in elderly patients 3

Critical Caveats

• Never combine ACE inhibitor with ARB due to increased hyperkalemia and renal dysfunction risk without additional BP benefit 2
• Use caution with thiazide diuretics in patients with gout history due to hyperuricemia risk 2
• Approximately 50% of patients diagnosed with resistant hypertension have pseudoresistance rather than true resistant hypertension 1
• Resistant hypertension affects around 10% of hypertensive individuals and increases risk of coronary artery disease, heart failure, stroke, end-stage renal disease, and all-cause mortality 1

Special Population: Hypertension in Pregnancy

For Preeclampsia Management: 1

• Treat hypertension urgently with oral nifedipine or IV labetalol/hydralazine if BP ≥160/110 mmHg
• Limit total fluid intake to 60-80 mL/h to avoid pulmonary edema
• Use MgSO4 for seizure prophylaxis in all preeclamptic women in low-middle income countries; selective use reasonable in high-income specialized centers
• Continue MgSO4 for 24 hours postpartum
• Monitor BP at least 4-6 hourly for at least 3 days postpartum
• Avoid NSAIDs in women with preeclampsia, especially with acute kidney injury