When should antihypertensive medication be started based on office blood pressure measurements in an adult?

When to Start Blood Pressure Medication Based on Office Measurements

Initiate antihypertensive medication immediately when confirmed office blood pressure is ≥140/90 mm Hg, regardless of cardiovascular risk, or when BP is ≥130/80 mm Hg in adults with established cardiovascular disease, diabetes, chronic kidney disease, or 10-year ASCVD risk ≥10%. 1

Blood Pressure Thresholds for Medication Initiation

Stage 2 Hypertension (≥160/100 mm Hg or ≥140/90 mm Hg)

• Start dual antihypertensive therapy immediately when office BP is ≥160/100 mm Hg (stage 2), combining two first-line agents from different classes or using a fixed-dose combination. 1
• For BP ≥140/90 mm Hg, initiate pharmacological treatment promptly alongside lifestyle modifications, irrespective of cardiovascular risk. 1
• When BP is >20/10 mm Hg above the patient's individualized target (<130/80 mm Hg for most adults), begin with dual therapy rather than monotherapy. 2

Stage 1 Hypertension (130-139/80-89 mm Hg)

• Initiate medication for BP 130-139/80-89 mm Hg in adults with any of the following high-risk conditions: 1
  • Established atherosclerotic cardiovascular disease (prior MI, stroke, coronary revascularization, peripheral arterial disease)
  • Type 2 diabetes mellitus
  • Chronic kidney disease (any stage)
  • 10-year ASCVD risk ≥10% (calculated using ACC/AHA Pooled Cohort Equations)
  • Age ≥65 years with additional cardiovascular risk factors
• For stage 1 hypertension without these high-risk features, attempt lifestyle modification for 3 months; if BP remains ≥130/80 mm Hg after this trial, start medication. 1

Elevated Blood Pressure (120-129/<80 mm Hg)

• In adults with elevated BP (120-129/<80 mm Hg) and sufficiently high cardiovascular risk, initiate pharmacological treatment after 3 months of lifestyle intervention if confirmed BP remains ≥130/80 mm Hg. 1
• For those with low-to-moderate CVD risk (<10% over 10 years), lifestyle measures alone are recommended initially. 1

Confirmation Requirements Before Starting Medication

Out-of-Office Blood Pressure Confirmation

• Base treatment decisions on an average of ≥2 readings obtained on ≥2 separate office visits, not a single elevated measurement. 1
• Use ambulatory BP monitoring (ABPM) or home BP monitoring (HBPM) to confirm the diagnosis and exclude white coat hypertension before initiating treatment in adults not already on medication. 1
• White coat hypertension (elevated office BP but normal out-of-office BP) carries cardiovascular risk similar to normotension and does not warrant immediate drug therapy. 1
• Masked hypertension (normal office BP but elevated out-of-office BP) carries risk equivalent to sustained hypertension and requires treatment. 1

Diagnostic Thresholds for Out-of-Office Monitoring

• Home BP ≥135/85 mm Hg or 24-hour ambulatory BP ≥130/80 mm Hg confirms true hypertension requiring pharmacological intervention. 2, 3

Initial Medication Selection

First-Line Monotherapy (Stage 1, Low Risk)

• For stage 1 hypertension with BP goal <130/80 mm Hg, initiation with a single antihypertensive drug is reasonable, followed by dosage titration and sequential addition of other agents. 1
• First-line options include thiazide or thiazide-like diuretics (chlorthalidone preferred over hydrochlorothiazide), ACE inhibitors, ARBs, or calcium channel blockers. 1, 4

First-Line Dual Therapy (Stage 2 or High Risk)

• For non-Black patients, combine an ACE inhibitor or ARB with a calcium channel blocker, or an ACE inhibitor or ARB with a thiazide diuretic. 2
• For Black patients, combine a thiazide diuretic with a calcium channel blocker as the preferred initial regimen. 2
• Fixed-dose single-pill combinations are strongly preferred to improve adherence. 1, 2

Blood Pressure Targets After Initiation

• Primary target: Systolic BP 120-129 mm Hg if well tolerated. 1
• Minimum acceptable target: <140/90 mm Hg for all hypertensive adults. 1
• High-risk patients (diabetes, CKD, established CVD, ASCVD risk ≥10%): <130/80 mm Hg. 1
• Reassess BP within 2-4 weeks after initiating therapy, with the goal of achieving target BP within 3 months. 2, 3

Special Populations

Older Adults (≥65 Years)

• Treatment thresholds and targets follow the same guidelines as younger adults if therapy is well tolerated. 1
• Maintain BP-lowering treatment lifelong, even beyond age 85, provided it is well tolerated. 1
• Test for orthostatic hypotension before starting or intensifying medication (measure BP after 5 minutes sitting/lying, then 1 and/or 3 minutes after standing). 1

Pregnancy

• Start drug treatment when confirmed office BP is ≥140/90 mm Hg in women with gestational or chronic hypertension. 1
• Target BP <140/90 mm Hg but not <80 mm Hg diastolic. 1
• Use dihydropyridine calcium channel blockers (extended-release nifedipine), labetalol, or methyldopa; avoid RAS blockers entirely. 1

Critical Pitfalls to Avoid

• Do not initiate treatment based on a single elevated office reading; confirm with repeat measurements or out-of-office monitoring. 1
• Do not delay medication in stage 2 hypertension (≥160/100 mm Hg or ≥140/90 mm Hg); prompt treatment within 2-4 weeks reduces cardiovascular risk. 2, 3
• Do not start monotherapy when BP is >20/10 mm Hg above target; dual therapy is required for adequate control. 1, 2
• Do not combine two RAS blockers (ACE inhibitor + ARB), as this increases adverse events without cardiovascular benefit. 1, 2
• Do not use beta-blockers as first-line agents unless compelling indications exist (heart failure, post-MI, angina, atrial fibrillation). 1, 2