Hypertension - Working Diagnosis

Scope: Adults with primary (essential) hypertension in primary care. Excludes secondary hypertension, hypertensive emergency, and hypertension in pregnancy.

Where they agree

Diagnosis requires confirmation with repeated measurements or ABPM/HBPM - white coat hypertension is common and should not trigger treatment
Lifestyle modification (sodium restriction, exercise, weight loss, DASH diet, alcohol reduction) is first-line for all patients and an ongoing adjunct to pharmacotherapy
All guidelines endorse a 5-drug class approach: ACE inhibitors/ARBs, calcium channel blockers (CCBs), thiazide/thiazide-like diuretics, beta-blockers, and mineralocorticoid receptor antagonists (MRAs) as the toolkit for resistant hypertension
Combination therapy (usually ACEi/ARB + CCB or thiazide) is required for most patients to reach target - monotherapy achieves targets in a minority
Renal function, electrolytes, and metabolic profile should be checked before starting pharmacotherapy and monitored after initiation
Never combine ACEi + ARB (increased adverse effects without benefit - ONTARGET)

Where they diverge

BP targets: ACC/AHA 2017 set <130/80 for most adults; ESC 2023 aligns with <130/80 for most adults under 70, accepting <140/90 for those ≥70; NZ BPAC/Heart Foundation uses absolute CVD risk framework - treatment threshold and target depend on calculated 5-year CVD risk, not BP alone
CVD risk framework: NZ uses the PREDICT-based NZ cardiovascular risk calculator; this distinguishes NZ practice from ESC (SCORE2), AHA (pooled cohort equations), and AU (NZ calculator often used in AU too, but Framingham-based AU calculator also used)
Treatment threshold: NZ treat if BP persistently ≥160/100, OR if BP ≥140/90 AND 5-year CVD risk ≥15% (or ≥10% with diabetes, CKD, or established CVD). This means a 45-year-old with BP 148/94 and low CV risk may not require pharmacotherapy in NZ - but would in ACC/AHA framework
Beta-blockers: ESC 2023 demoted beta-blockers from routine first-line (preferred for specific indications: AF rate control, HF, post-MI, angina). AHA/ACC: acceptable first-line for some patients. NZ BPAC: beta-blockers are acceptable but generally 3rd or 4th line for uncomplicated hypertension
Spironolactone for resistant hypertension: ESC, AHA, and most guidelines recommend spironolactone as fourth-line. PATHWAY-2 RCT showed spironolactone superior to bisoprolol and doxazosin as fourth-line add-on. NZ PHARMAC funds spironolactone.

Comparison

Domain	NZ - BPAC / Heart Foundation 2024	AU - Heart Foundation 2023	International - ESC 2023
Diagnosis and confirmation	BP ≥140/90 on ≥2 separate occasions (different visits), or ≥160/100 on one occasion. ABPM or HBPM recommended to exclude white coat hypertension before committing to lifelong therapy. Grade 1 (140-159/90-99), Grade 2 (≥160/≥100) broadly used. BPAC recommends HBPM (mean of readings over 5-7 days) as practical alternative to ABPM.	Consistent with international definitions. Confirm with ABPM/HBPM before initiating pharmacotherapy for Grade 1 unless CV risk is high.	Grade 1: 140-159/90-99. Grade 2: ≥160/≥100. ABPM/HBPM required to confirm diagnosis in most patients. Masked hypertension (normal in clinic, elevated at home) warrants treatment.
Treatment threshold - risk-stratified	Pharmacotherapy threshold is risk-stratified. Treat if: (1) BP ≥160/100 regardless of CV risk, OR (2) BP ≥140/90 AND 5-year CVD risk ≥15%, OR (3) BP ≥140/90 AND established CVD, CKD, or diabetes. For patients below these thresholds: lifestyle modification and monitoring every 3-6 months. This means many patients with BP 140-159/90-99 and low absolute CV risk will not receive pharmacotherapy in NZ practice - a meaningful departure from ACC/AHA 2017.NZ approach	Similar risk-stratified approach. Heart Foundation AU recommends treatment initiation at ≥160/100 universally, and ≥140/90 if CVD risk is elevated or target organ damage is present.	Treat Grade 1 (140-159/90-99) for all adults with established CVD or very high CV risk. For others with Grade 1: treat after lifestyle modification trial of 3-6 months if BP remains elevated. Grade 2 (≥160/≥100): initiate pharmacotherapy promptly. ACC/AHA 2017 is more aggressive: treat at ≥130/80 for patients with CVD or 10-year ASCVD risk ≥10% - this is stricter than ESC and well beyond NZ practice.
BP targets	For treated hypertension: target <130/80 for most patients under 75 with high CV risk. <140/90 acceptable for lower-risk patients and those ≥75. Individualize for frail older adults - overtreating increases falls risk. BPAC: avoid BP <120 systolic in elderly patients on antihypertensives.	<130/80 for high-risk patients (established CVD, diabetes, CKD, or CVD risk ≥15%). <140/90 for lower-risk patients.	<130/80 for most adults <70. <140/80 for adults ≥70 (systolic target 130-139 if tolerated). AHA/ACC 2017: <130/80 for all patients with hypertension and CVD risk ≥10%.
First-line pharmacotherapy	ACEi (lisinopril, ramipril) or ARB (losartan, irbesartan) - first-line, especially with diabetes, CKD, or proteinuria. PHARMAC funds: ramipril, enalapril, lisinopril, losartan, irbesartan.Funded CCB (amlodipine) - first-line, especially in elderly, Afro-Caribbean patients, or those intolerant of ACEi/ARB. PHARMAC funds amlodipine.Funded Thiazide-like diuretic (indapamide, bendroflumethiazide) - first-line option, especially in isolated systolic hypertension. Hydrochlorothiazide less preferred than indapamide (evidence base weaker). For most patients, start combination therapy if BP ≥20/10 mmHg above target (dual therapy more effective than monotherapy dose-escalation).	Consistent class selection. ACEi/ARB + CCB combination widely used. PBS funds ACEi, ARBs, amlodipine, indapamide.PBS	ACEi/ARB + CCB or thiazide as initial combination for most patients. Single-pill combinations (SPC) improve adherence - NZ has limited SPC options funded by PHARMAC. Beta-blockers: preferred for specific indications (AF, HF, post-MI, angina, pregnancy) not routine first-line.
Resistant hypertension	Define as BP ≥140/90 on ≥3 antihypertensives at optimal doses (including a diuretic), after excluding: white coat hypertension, non-adherence, secondary causes, drug interactions (NSAIDs, licorice, decongestants, combined OCP). Add spironolactone 25-50 mg (PATHWAY-2 evidence; PHARMAC-funded).Funded Check aldosterone/renin ratio to exclude primary hyperaldosteronism before adding spironolactone. Refer to secondary care if true resistant hypertension confirmed.	Identical approach. Spironolactone as fourth-line endorsed by NHFA.	Spironolactone as fourth-line add-on (Class IIa, A). Amiloride as alternative if spironolactone not tolerated. Doxazosin (alpha-blocker) or bisoprolol as fourth-line alternatives. Renal denervation: emerging option for resistant hypertension in selected patients - specialist setting only.
Hypertension in older adults - age ≥70	Target <140/90 for most patients ≥70; <150 systolic acceptable if patient is frail, has history of falls, or is on multiple antihypertensives. BPAC cautions against aggressive treatment in frail elderly - standing BP should be checked (orthostatic hypotension risk). Thiazides and ACEi/ARB are preferred; avoid excessive diuresis.	Consistent.	Target 130-139 systolic for fit older adults; 140-149 acceptable for frail patients or those with multiple comorbidities. The SPRINT trial excluded frail patients and cannot be extrapolated to nursing home populations.
Special populations - diabetes and CKD	ACEi or ARB first-line for all hypertensive patients with diabetes or CKD with proteinuria (renoprotective effect beyond BP lowering). Target <130/80. Avoid ACEi + ARB combination. For CKD without proteinuria: any first-line class acceptable.	Consistent.	Consistent. SGLT2i (empagliflozin, dapagliflozin) provide additional BP lowering (~3-5 mmHg systolic) and are increasingly used as part of the treatment strategy in T2D + hypertension given their cardiovascular and renal benefits.

NZ clinical context

The NZ cardiovascular risk framework and what it means for treatment thresholds

Why NZ treatment thresholds differ from international guidelines

The fundamental difference between NZ practice and international guidelines is not the target BP but the treatment threshold. NZ does not treat every patient with BP 140-159/90-99: it asks first what their absolute cardiovascular risk is. A 45-year-old nonsmoking woman with BP 148/94, no diabetes, and a 5-year CVD risk of 4% does not automatically receive pharmacotherapy in NZ. She receives lifestyle counselling and 6-monthly monitoring. This is clinically defensible: the absolute benefit of treating low-risk Grade 1 hypertension is modest, and the NNT is high.

The NZ CVD risk calculator (PREDICT)

The NZ CVD risk calculator (PREDICT-based, available via PMS systems and online) is the tool. It uses age, sex, ethnicity, BP, total/HDL cholesterol, smoking status, diabetes, deprivation index, and family history to generate a 5-year CVD risk score. This is more comprehensive than Framingham and has been validated in the NZ population, including Maori and Pacific peoples where traditional risk calculators underestimate risk.

Ethnicity adjustment in the PREDICT calculator

For Maori and Pacific patients: the NZ calculator includes an ethnicity adjustment that increases estimated risk in Maori, Pacific, and South Asian patients. This is appropriate - these populations have higher rates of CVD at lower traditional risk factor burdens, and the ethnicity-adjusted score more accurately reflects true risk. Be explicit with patients about what the score means and why the threshold matters.

PHARMAC-funded antihypertensives

PHARMAC-funded agents for hypertension: ramipril, lisinopril, enalapril (ACEi); losartan, irbesartan (ARB); amlodipine (CCB); bendroflumethiazide, indapamide (thiazide/thiazide-like); spironolactone (MRA for resistant hypertension).Funded

Fixed-dose combination tablets: limited PHARMAC-funded options; most patients will be on separate tablets. A practical note: the most common treatment failure is non-adherence and inadequate dose titration, not drug class choice. Before adding a third agent, confirm the patient is taking the first two at effective doses. Pill burden is a major adherence barrier; where a combination tablet is affordable and available, it is worth discussing.

A practical NZ prescribing sequence

Most patients with Grade 1 hypertension (BP 140-159/90-99) in NZ will follow this pathway:

Step 1 (all patients): Confirm diagnosis with HBPM (mean of 5-7 readings at home) or ABPM. Calculate 5-year CVD risk using the online NZ calculator or via PMS. Check baseline eGFR, electrolytes, and consider secondary causes if indicated (family history, young age at onset, resistant patterns).
Step 2 (all patients): Intensive lifestyle modification: sodium restriction (<2300 mg/day), aerobic exercise (≥150 min/week), DASH diet pattern, weight loss target (5-10% for overweight), alcohol moderation, smoking cessation if applicable. Review at 3-6 months before committing to pharmacotherapy for Grade 1 if CV risk is not very high.
Step 3 (if treatment threshold met): Start dual therapy if BP is ≥20/10 above target. For most patients: ACEi/ARB + CCB or thiazide-like diuretic. Typical regimens: ramipril 5-10 mg + amlodipine 5-10 mg, or losartan 50-100 mg + indapamide 2.5 mg. Both are PHARMAC-funded if prescribed separately.
Step 4 (if needed): For resistant hypertension, add spironolactone 25 mg. Check U&E 1-2 weeks after initiation and after each dose adjustment. Avoid K+ supplementation unless eGFR is very low. Monitor for gynaecomastia (may require switch to amiloride).

Standing BP in older adults: preventing falls

In patients ≥70, always check standing BP after 1-3 minutes from lying or sitting. A systolic drop ≥20 mmHg or diastolic drop ≥10 mmHg with symptoms (dizziness, syncope) warrants dose reduction or regimen change. This is the most commonly overlooked safety measure in older hypertensive patients and is a major contributor to falls, which carry substantial morbidity in this age group.

Secondary hypertension screening - when to refer

Refer to secondary care or specialist hypertension clinic if:

Age <30 with hypertension and no family history
Abrupt onset or sudden worsening of previously well-controlled hypertension
BP ≥180/120 in the absence of established target organ damage
Hypokalaemia (<3.0 mmol/L) with normal renal function on diuretics
Clinical suspicion of secondary causes (symptoms of hyperaldosteronism, pheochromocytoma, renal artery stenosis)
True resistant hypertension on optimal triple therapy

Bottom line for NZ practice

What this means in the consulting room

Before starting pharmacotherapy for BP 140-159/90-99, calculate 5-year CVD risk using the NZ calculator. Treat at ≥140/90 only if CVD risk ≥15%, or if they have established CVD, diabetes, or CKD. This may mean some patients with Grade 1 hypertension leave the practice without antihypertensive therapy but with a strong lifestyle plan and a review date.
For most patients who do need pharmacotherapy, start combination therapy if BP is ≥20/10 above target. Monotherapy is the exception, not the rule. Amlodipine + ramipril or losartan is effective, inexpensive (both PHARMAC-funded), and a reasonable starting combination.
Target <130/80 for patients under 75 with high CV risk. For patients ≥75 or those with frailty, accept <140/90 and check standing BP at every visit. Falls from orthostatic hypotension are a serious hazard in older adults on aggressive BP-lowering therapy.
For resistant hypertension, add spironolactone 25 mg before adding a fourth agent from a different class. PATHWAY-2 evidence is clear: spironolactone is superior to other fourth-line alternatives. Check U&E at baseline and 1-2 weeks after any dose change.
Apply the ethnicity adjustment in the NZ CVD risk calculator for Maori, Pacific, and South Asian patients. It is there because these populations carry higher cardiovascular risk at comparable BP and lipid levels. Document their CVD risk score in the medical record so future practitioners do not re-treat inappropriately.

Sources

Williams B, Mancia G, Spiering W, et al. 2018 ESC/ESH Guidelines for the management of arterial hypertension. Eur Heart J. 2018;39(33):3021-3104.
Whelton PK, Carey RM, Aronow WS, et al. 2017 ACC/AHA guideline for the prevention, detection, evaluation, and management of high blood pressure in adults. J Am Coll Cardiol. 2018;71(19):e127-e248.
Heart Foundation New Zealand. Primary care management of hypertension. Wellington: Heart Foundation; 2024.
BPAC NZ. Management of hypertension in adults. Best Practice Journal. 2024. Available at bpac.org.nz.
Kario K, Shimbo D, Hoshide S, et al. Emergence of home blood pressure-guided management of hypertension based on global evidence. Hypertension. 2019;74(2):229-236.
Williams B, MacDonald TM, Morant S, et al. Spironolactone versus placebo, bisoprolol, and doxazosin to determine the optimal treatment for drug-resistant hypertension (PATHWAY-2). Lancet. 2015;386(10008):2059-2068.