Hypertensive Nephrosclerosis

Meet the patient

A 68-year-old man is referred to nephrology after routine bloods show an eGFR of 42 and a urine albumin-to-creatinine ratio of 90. His blood pressure has hovered around 165/95 for fifteen years on whatever tablets he remembers to take; his ECG shows left ventricular hypertrophy and his fundi show arteriolar narrowing. Both kidneys are 8.5 cm and echogenic on ultrasound.^[1][2]

The whole topic turns on one fork. Most of the time you lower this man's pressure slowly and protect the nephrons he has left. But if his blood pressure one day hits 220/130 with papilloedema and a doubling creatinine, the same number becomes an emergency in which lowering it too fast is as dangerous as leaving it high.^[1]

"Benign" that isn't — the small granular kidney

Hypertension is the most common chronic disease of adults worldwide, affecting more than one billion people, and the kidney is one of its prime target organs. Hypertensive nephrosclerosis is the chronic renal injury that results from long-standing systemic hypertension, characterised structurally by hyaline arteriolosclerosis of the afferent arterioles with downstream ischaemic glomerulosclerosis, tubular atrophy and interstitial fibrosis, and clinically by slowly progressive chronic kidney disease (CKD) with sub-nephrotic proteinuria and a bland urinary sediment.^[1][2]

The term nephrosclerosis (literally, "hardening of the kidney") reflects the gross appearance — the kidney becomes small, contracted, and granular with a thinned cortex, a finding already familiar to pathologists of the 19th century. The traditional label "benign nephrosclerosis" is misleading: although slow, the process is the second commonest cause of end-stage kidney disease (ESKD) worldwide (after diabetic kidney disease), and the cardiovascular disease it accompanies is the leading cause of death in this population.^[1]

The clinical skill the topic demands is twofold. First, control chronic hypertension tightly to prevent and slow CKD progression — using RAAS blockade (an ACE inhibitor or ARB), an SGLT2 inhibitor in established CKD, and cardiovascular risk reduction. Second, recognise malignant-phase (accelerated) hypertension — the severe, acute form — and lower the blood pressure fast enough to stop ongoing organ damage but controlled enough to avoid precipitating ischaemic stroke, MI or AKI.^[2]

Etymology for viva gold: nephrosclerosis welds Greek nephros, "kidney", to skleros, "hard" — quite literally a hardening of the kidney, which is exactly what the pathologist sees as the small, gritty, granular organ. The label "benign" is a 19th-century misnomer that clung on because the disease is slow, not because it is kind — untreated, it is the second commonest route to dialysis.^[1]

Classification

Hypertensive nephrosclerosis is classified by tempo, severity and histology into the slow benign (chronic) form and the acute malignant (accelerated) phase. The two are ends of a spectrum — a patient with long-standing benign nephrosclerosis can decompensate into a malignant phase — but they differ sharply in urgency and management. ^[1]

^{[12] [14]}

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A second, clinically vital classification is the distinction between a hypertensive emergency and a hypertensive urgency. Both feature severe BP; what separates them is the presence or absence of acute target-organ damage, and this single distinction dictates the speed and setting of treatment.^[3]

Epidemiology & Risk Factors

Hypertension is the leading modifiable risk factor for global mortality and affects more than one billion adults. As a cause of ESKD, hypertensive nephrosclerosis accounts for roughly 25–30 percent of patients reaching dialysis or transplantation in most registries — second only to diabetic kidney disease.^[1][2] The burden is unevenly distributed: in people of recent West-African ancestry (broadly, Black/African populations), hypertensive nephrosclerosis is the dominant non-diabetic cause of ESKD, with earlier onset, more severe disease and faster progression than in European-ancestry populations.^[6]

The risk factors for developing and progressing hypertensive nephrosclerosis are: ^[1]

• Age — prevalence of both hypertension and arteriolar thickening rises steeply with age; the kidney of the elderly hypertensive is the archetype.
• Black / African ancestry and APOL1 risk variants — the G1 and G2 variants of the APOL1 gene explain much of the markedly higher ESKD risk in this population. APOL1 is a component of the high-density lipoprotein particle; the risk variants arose through positive selection because they confer resistance to Trypanosoma brucei rhodesiense (sleeping sickness), but they also cause a markedly increased risk of FSGS, hypertensive nephrosclerosis and HIV-associated nephropathy. This genetic explanation has reframed what was historically attributed to "race".^[6]
• Family history and low birth weight — reflecting both genetic and developmental (reduced nephron number) contributions.
• Obesity, high dietary sodium, low potassium intake, physical inactivity, excess alcohol — the lifestyle drivers of hypertension generally.
• Coexisting diabetes, dyslipidaemia, smoking — accelerate vascular injury and produce mixed ("hypertensive–diabetic") nephropathy.
• Socioeconomic deprivation and therapeutic non-adherence — major drivers of severe and malignant-phase presentation.

Malignant-phase hypertension is rare (incidence approximately 1–2 per 100,000 per year in Europe) but disproportionately affects Black and South-Asian populations, untreated or non-adherent patients, and those with an underlying secondary cause (renal artery stenosis, renovascular disease, phaeochromocytoma, scleroderma renal crisis).^[2]

Pathophysiology

The central lesion of hypertensive nephrosclerosis is hyaline arteriolosclerosis of the afferent (preglomerular) arteriole. Understanding how this single lesion produces the whole syndrome requires following the haemodynamic, structural and humoral consequences of chronic pressure overload. ^[1]

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Step 1 — Pressure transmission to the afferent arteriole

The kidney autoregulates its blood flow and glomerular filtration rate (GFR) across a wide range of systemic pressures by adjusting the tone of the afferent and efferent arterioles. When systemic BP rises, the myogenic response of the afferent arteriole constricts to shield the delicate glomerular capillary tuft. In chronic hypertension, this protective mechanism is overwhelmed: sustained high pressure transmits mechanical stress to the afferent endothelium and smooth muscle, injuring them and triggering the insudation of plasma proteins and lipids into the arteriolar wall — the hyaline change seen on light microscopy. The vessel wall thickens, the lumen narrows, and — critically — the arteriole becomes rigid, losing its ability to constrict or dilate.^[1][2]

Step 2 — Loss of autoregulation: glomerular hypertension AND ischaemia

Once the afferent arteriole is rigid, autoregulation fails, and two opposing injuries follow from the same lesion: ^[1]

• When systemic pressure is high, the stiff afferent cannot buffer it, and the pressure is transmitted directly to the glomerulus, producing intraglomerular hypertension. This drives podocyte stress and effacement, mesangial expansion, and a focal segmental glomerulosclerosis (FSGS)-like scarring — the hyperfiltration injury pathway.
• When systemic pressure falls (volume depletion, sleep, antihypertensive therapy), the stiff afferent cannot dilate to maintain flow, and the glomerulus becomes ischaemic, undergoing ischaemic glomerulosclerosis — solidification and global sclerosis with surrounding periglomerular fibrosis, tubular atrophy and interstitial fibrosis. ^[1]

Both pathways converge on the same endpoint — nephron loss and interstitial fibrosis — the structural correlate of progressive CKD. The histological hallmarks are therefore: hyaline arteriolosclerosis, ischaemic (solidified) glomeruli, periglomerular fibrosis, tubular atrophy, and a fibrotic interstitium, producing the gross picture of a small, contracted, granular kidney.^[2]

Step 3 — The RAAS amplifies injury

Ischaemic juxtaglomerular cells release renin, which cleaves angiotensinogen to angiotensin I, converted by angiotensin-converting enzyme (ACE) to angiotensin II. Angiotensin II has three renal effects that worsen the disease: ^[1]

• Preferential efferent arteriolar constriction, which raises intraglomerular pressure and worsens the pressure transmission and protein leak.
• Direct pro-fibrotic signalling on mesangial cells, podocytes and tubular cells (TGF-β, NF-κB), accelerating scarring.
• Aldosterone release, which drives sodium retention (worsening hypertension) and has direct profibrotic effects on the heart and kidney. ^[1]

This is the mechanistic rationale for why ACE inhibitors and ARBs are uniquely renoprotective beyond their blood-pressure effect — they dilate the efferent arteriole, lower intraglomerular pressure, and interrupt the pro-fibrotic signalling cascade.^[6]

Step 4 — Malignant phase: vessel rupture and thrombotic microangiopathy

When the BP rise is severe and abrupt, the vessel wall fails outright. Endothelial injury allows plasma proteins and fibrin to flood the intimal and medial layers, producing fibrinoid necrosis of the arterioles — a pink, acellular, amorphous material on light microscopy. In the larger interlobular arteries, a concentric proliferation of myofibroblasts produces the "onion-skin" hyperplastic arteriolitis. Endothelial injury activates platelets and the coagulation cascade, and red cells are sheared against the damaged vessel wall — producing a thrombotic microangiopathy with schistocytes on the blood film, a falling platelet count, rising LDH, and acute kidney injury.^[2]

The governing equation

Glomerular filtration obeys Starling forces across the glomerular capillary: ^[1]

GFR = Kf × (P_GC − P_BS − π_GC) ^[1]

where P_GC is the glomerular capillary hydrostatic pressure (set by the balance of afferent versus efferent arteriolar tone), P_BS is the Bowman's space hydrostatic pressure, π_GC is the glomerular oncotic pressure, and Kf is the ultrafiltration coefficient (the product of surface area and permeability, reduced by mesangial contraction and podocyte loss). In hypertensive nephrosclerosis, P_GC rises (afferolular pressure transmission, efferent angiotensin-II constriction), then falls as afferolular occlusion and Kf loss dominate — explaining the early hyperfiltration and late progressive decline. ^[1]

^[1]

Clinical Presentation

Chronic (benign) hypertensive nephrosclerosis

The presentation is insidious. A typical patient is middle-aged or older, with long-standing — often poorly controlled — hypertension, frequently with coexisting ischaemic heart disease, heart failure, stroke, peripheral vascular disease, or diabetes. The renal disease declares itself through: ^[1]

• Slowly progressive loss of kidney function — the arteriolosclerosis, ischaemic glomerulosclerosis and tubulointerstitial fibrosis of nephrosclerosis predict the decline of renal function.^[12]
• Albuminuria — a core marker of kidney damage in CKD alongside reduced eGFR; albuminuria of 300 mg per 24 hours or more marks high risk of progression and warrants prompt nephrology referral.^[1]
• Accelerated cardiovascular risk — most patients with CKD are at risk of accelerated cardiovascular disease and death.^[2]
• In people of recent African ancestry, expect a severe, early form of renovasculopathy with a rapid course to renal failure and predominant FSGS lesions.^[12]

The patient is often asymptomatic until the CKD is advanced, when uraemic symptoms (fatigue, anorexia, pruritus, nocturia) or fluid overload appear. ^[1]

Malignant-phase (accelerated) hypertension

The presentation is acute and dramatic. The patient has severe BP, typically over 180/120 mmHg, with one or more of: ^[1]

• Headache, visual disturbance, confusion, seizures, or focal deficit — hypertensive encephalopathy.
• Chest pain or dyspnoea — acute coronary syndrome, acute pulmonary oedema, or aortic dissection.
• Oliguria, haematuria, or rapidly rising creatinine — acute kidney injury.
• Pallor, jaundice, fatigue — microangiopathic haemolytic anaemia with schistocytes on blood film.
• Fundoscopic findings of grade III–IV retinopathy: flame-shaped haemorrhages, cotton-wool spots (ischaemic nerve-fibre-layer infarcts), hard exudates, and papilloedema. ^[1]

Atypical presentations examiners probe deliberately

• The elderly with isolated systolic hypertension and a wide pulse pressure — stiff, atherosclerotic vasculature; check standing BP for orthostatic hypotension before intensifying therapy.
• The patient presenting for the first time with advanced CKD and small kidneys — the kidney disease is already irreversible; the goal is to slow further decline and manage cardiovascular risk.
• The "asymptomatic hypertensive" discovered on screening with proteinuria or reduced eGFR — do NOT dismiss as benign; assess end-organ damage fully.
• In diabetic patients — overlap with diabetic kidney disease: heavier proteinuria, Kimmelstiel–Wilson nodules on biopsy, and diabetic retinopathy (which favours the diabetic component); arteriolar hyalinosis, however, is shared.
• Clues to a secondary cause rather than primary hypertension: age under 30, abrupt onset, severe or resistant hypertension, abdominal bruit (renovascular), spontaneous hypokalaemia (primary aldosteronism), the triad of episodic headache, palpitations and sweating (phaeochromocytoma), unequal kidney size (renal artery stenosis). ^[1]

Differential Diagnosis

The diagnosis of hypertensive nephrosclerosis is one of exclusion — chronic hypertension with sub-nephrotic proteinuria and small kidneys is consistent with it, but several other causes of CKD must be actively considered and excluded.^[1][2]

^{[13] [2] [8] [17] [18]}

Two further differentials: ^[1]

• Atheroembolic renal disease — follows recent catheterisation, angiography or anticoagulation; showers of cholesterol emboli produce AKI (rather than slow CKD), eosinophilia, livedo reticularis, blue toes, and hypocomplementaemia.
• Hypertensive emergency vs urgency — already discussed under Classification; the distinction rests entirely on acute target-organ damage, not the BP number itself. ^[1]

Clinical & Bedside Assessment

The bedside assessment of a hypertensive patient serves two purposes — to quantify the blood pressure correctly and to screen for end-organ damage and secondary causes. ^[1]

Correct blood-pressure measurement

Errors of technique are the commonest source of misdiagnosis. Measure correctly: ^[1]

• Rest for 5 minutes, seated, feet flat on the floor, arm supported at heart level, correct cuff size (bladder over 80% of arm circumference — too small over-reads).
• Take two to three readings, 1 minute apart, both arms at the first visit (a difference over 15–20 mmHg suggests subclavian/renovascular disease). Use the higher arm thereafter.
• Confirm with ambulatory (ABPM) or home monitoring to exclude white-coat and masked hypertension; ABPM is the gold standard.
• Check standing BP after 1–3 minutes in older patients and those on therapy to detect orthostatic hypotension (drop over 20/10 mmHg). ^[1]

End-organ damage assessment

• Fundoscopy — grade the hypertensive retinopathy using Keith–Wagener–Barker: ^[1]

• Cardiovascular exam — displaced/heaving apex and S4 gallop of LVH, murmurs, peripheral pulses (radio-femoral delay of coarctation; absent/diminished pulses of vascular disease), and bruits (carotid, abdominal over the renal artery, femoral).
• Chest — basal crackles of pulmonary oedema; pleural effusions.
• Abdomen — palpable bladder (obstruction), palpable kidneys (polycystic kidney disease), abdominal bruit (renal artery stenosis).
• Neurology — focal deficits, encephalopathy, signs of prior stroke. ^[1]

Volume status and a focused review

In malignant-phase hypertension, examine for fluid overload (JVP, crackles, oedema) versus dehydration (which can drive RAAS activation), and review the drug chart for non-adherence, sympathomimetics, NSAIDs, oral contraceptives, and herbal/licorice (glycyrrhizin-induced apparent mineralocorticoid excess). ^[1]

Investigations

Investigations serve four goals: confirm CKD and stage it, quantify proteinuria, exclude other causes, and screen for secondary hypertension when indicated. ^[1]

First-line (all patients)

CKD definition and staging — KDIGO

CKD is defined as a persistent abnormality in kidney structure or function for more than 3 months — for example eGFR under 60 mL/min/1.73 m² or albuminuria (30 mg per 24 hours or more).^[1] Staging and risk-assessment tools incorporate both GFR and albuminuria to guide treatment, monitoring and referral:

ECG criteria for left ventricular hypertrophy

• Sokolow-Lyon: SV1 + (RV5 or RV6) over 35 mm.
• Cornell voltage: R in aVL + S in V3 — over 28 mm in men, over 20 mm in women.
• Cornell product: Cornell voltage × QRS duration — over 2436 mm·ms.
• Strain pattern: ST-segment depression and T-wave inversion in the lateral leads (V5–V6, I, aVL). ^[1]

Renal ultrasound

The classic finding is bilateral, symmetric, small (under 9–10 cm) echogenic kidneys with cortical thinning. Findings that argue against pure hypertensive nephrosclerosis and demand further work-up: ^[1]

• Asymmetry (over 1.5 cm size difference) → renovascular disease.
• Large kidneys → diabetic kidney disease, polycystic kidneys, infiltrative disease, or acute inflammation superimposed on CKD.
• Hydronephrosis → obstructive uropathy. ^[1]

Screening for secondary causes (indicated by resistant, early-onset, severe, or malignant hypertension)

• Primary aldosteronism — aldosterone-to-renin ratio (ARR) (screen; positive if ARR over 30 with aldo over 15 ng/dL), confirmed by saline or captopril suppression testing; adrenal CT then adrenal vein sampling.
• Renal artery stenosis — renal Doppler ultrasound (resistive indices, peak systolic velocity), CT angiography or MR angiography (gold-standard imaging; catheter angiography reserved for intervention).
• Phaeochromocytoma — 24-hour fractionated urine metanephrines or plasma free metanephrines.
• Cushing syndrome — 1 mg overnight dexamethasone suppression test, 24-hour urine cortisol, late-night salivary cortisol.
• Coarctation of the aorta (younger patients, radio-femoral delay, bruits) — CT/MR angiography or echocardiography.
• Obstructive sleep apnoea — sleep study (polysomnography).
• Renal parenchymal disease — consider biopsy if presentation atypical (heavy proteinuria, haematuria, rapid decline, large kidneys). ^[1]

Investigations specific to suspected malignant hypertension

Add blood film and LDH/haptoglobin (microangiopathic haemolysis with schistocytes), platelet count and coagulation, troponin and repeat ECG, and urgent renal function; fundoscopy is essential and diagnostic when grade III–IV changes are present. ^[1]

^[1]

Lower controlled, never precipitous — the 25 percent rule

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This section concerns malignant-phase hypertension and other hypertensive emergencies — the time-critical state. Chronic management is covered in the next section. ^[1]

The governing principle: lower controlled, never precipitous

In a hypertensive emergency the aim is NOT to normalise the blood pressure quickly. Chronic hypertension shifts the cerebral autoregulation curve to the right — the brain, heart and kidneys have adapted to the higher pressures and rely on them for perfusion. A precipitous fall drops cerebral, coronary and renal perfusion and causes ischaemic stroke, myocardial infarction, and acute kidney injury — the central, classic pitfall of treating a hypertensive emergency.^[2][3]

^[15]

Setting, monitoring, and agents

Admit to an intensive care setting — hypertensive emergency recommendations consistently call for intravenous antihypertensives in intensive care.^[23] Large randomised trial evidence is lacking in this area, but recent data document the safety and efficacy of labetalol and nicardipine, and many parenteral choices with varied mechanisms of action exist.^[16]

• Labetalol and nicardipine are the best-evidenced intravenous agents for hypertensive crises.^[16]
• Depending on the clinical presentation, parenteral or oral therapy can initiate BP lowering; ischaemic stroke and heart failure or pulmonary oedema are the commonest forms of organ damage in hypertensive emergencies.^[14][16]

Scenario-specific targets

Different emergencies have different targets — learn the contrasts: ^[1]

Fluid and electrolyte management

• Avoid volume overload — if pulmonary oedema coexists, treat with loop diuretic and preload reduction alongside BP control.
• Watch for and treat hyperkalaemia and acute kidney injury; in the acute emergency, do NOT start an ACE inhibitor/ARB — the acute fall in efferent tone can precipitate AKI, especially if bilateral renovascular disease is present (often unrecognised). ^[1]

ACEi or ARB, then SGLT2 — the renoprotective ladder

Chronic management has three pillars: (1) tight blood-pressure control, (2) RAAS blockade plus an SGLT2 inhibitor, and (3) cardiovascular risk reduction. Each is supported by landmark trials. ^[1]

Pillar 1 — Blood-pressure target: tight, individualised

The blood-pressure target has fallen over successive guidelines and trials: ^[1]

• SPRINT (NEJM 2015) — in over 9,000 high-risk patients, an intensive standardised SBP target under 120 mmHg (versus under 140) reduced cardiovascular events and all-cause mortality by roughly 25 percent, without excess in serious adverse events — including in the elderly subgroup. The trial excluded patients with diabetes, prior stroke, heart failure, recent MI, and those in nursing homes.^[5]
• KDIGO 2021 (BP in CKD) — recommends SBP under 120 mmHg (standardised, office) in adults with CKD and hypertension, when tolerated.^[1]
• 2017 ACC/AHA (US) — BP target under 130/80 for most adults, including those with CKD.^[3]
• 2018 ESC/ESH (Europe) — initial target under 140/90, then under 130/80 if tolerated, especially in CKD; under 140 in older/frail patients.^[4]

^{[1] [1]}

The shared principle is unambiguous: tight control, with RAAS blockade, individualised to the patient's tolerance and comorbidity. ^[1]

Pillar 2 — RAAS blockade is first-line and uniquely renoprotective

Begin with an ACE inhibitor OR an ARB (never both together — ONTARGET showed harm with no benefit). ACE inhibitors and ARBs dilate the efferent arteriole, lower intraglomerular pressure, reduce proteinuria, and interrupt the pro-fibrotic actions of angiotensin II. They are uniquely renoprotective beyond their blood-pressure effect.^[6]

Common agents and oral doses: ^[1]

The expected creatinine rise on starting an ACE inhibitor/ARB — an acute rise in serum creatinine of up to 30 percent that stabilises within the first 2 months of therapy is haemodynamic and is associated with long-term preservation of renal function. Withdraw the ACE inhibitor only when the rise exceeds 30 percent above baseline within the first 2 months, or when hyperkalaemia develops (serum potassium 5.6 mmol/L or greater).^[20] Separately, a creatinine rise of at least 50 percent within one week of starting an ACE inhibitor or ARB should prompt consideration of renovascular hypertension.^[17]

^[1]

Pillar 3 — Step-up therapy to reach target

If the BP target is not met on an ACE inhibitor/ARB alone, step up: ^[1]

1. Add a dihydropyridine calcium-channel blocker — the ACE-inhibitor/ARB + CCB pairing is the best-evidenced two-drug regimen: in ACCOMPLISH, benazepril plus amlodipine reduced cardiovascular events by about 20 percent versus benazepril plus hydrochlorothiazide (hazard ratio 0.80), with a 2.2 percent absolute risk reduction.^[21]
2. Add a thiazide-type diuretic — in ALLHAT, chlorthalidone 12.5 to 25 mg daily was an effective first-step agent in high-risk hypertension, with amlodipine 2.5 to 10 mg daily and lisinopril 10 to 40 mg daily as randomized alternatives.^[7]
3. If more agents are needed, think resistant hypertension — confirm adherence and out-of-office BP, exclude secondary causes, and add a mineralocorticoid receptor antagonist as the fourth-line drug.^[22]

Resistant hypertension and the fourth agent

Resistant hypertension is BP remaining above target despite lifestyle measures and at least three antihypertensive agents at maximally tolerated doses — typically a long-acting calcium-channel blocker, a RAAS blocker (ACE inhibitor or ARB) and a diuretic — after adherence is confirmed, BP is confirmed with out-of-office measurement, and secondary causes are excluded.^[22] The fourth-line agent of choice is a mineralocorticoid receptor antagonist such as spironolactone, as demonstrated in the PATHWAY-2 trial and meta-analyses; alternatives include amiloride, doxazosin, eplerenone, clonidine and beta-blockers.^[22][25] Single-pill combination therapy at maximally tolerated doses, reduced sodium and alcohol intake, physical activity and weight loss are key adjuncts.^[22]

Pillar 4 — Add an SGLT2 inhibitor to CKD

The SGLT2 inhibitors reduce intraglomerular pressure (tubuloglomerular feedback restoration) and are now foundational CKD therapy, on top of RAAS blockade, regardless of glycaemic status: ^[1]

• Dapagliflozin 10 mg OD — DAPA-CKD (NEJM 2020) reduced the composite of sustained eGFR decline, ESKD, or renal/cardiovascular death by 39 percent, with benefit seen regardless of diabetes.^[9]
• Empagliflozin 10 mg OD — EMPA-KIDNEY (NEJM 2023) confirmed a 28 percent relative risk reduction in kidney-disease progression or cardiovascular death across a broad CKD population including non-diabetic and lower-eGFR patients.^[10]
• Canagliflozin — CREDENCE (NEJM 2019) in diabetic kidney disease.^[8]

Current indication: SGLT2 inhibitors are established CKD therapy with or without type 2 diabetes, given in addition to existing therapy. The evidence base is albuminuric CKD: DAPA-CKD enrolled eGFR 25 to 75 mL/min/1.73 m² with UACR 200 to 5000 (dapagliflozin 10 mg once daily); EMPA-KIDNEY enrolled eGFR down to 20 (or up to 90 with UACR 200 or more) with empagliflozin 10 mg once daily.^[9][10]

Pillar 5 — Cardiovascular risk reduction

Because cardiovascular disease is the leading cause of death in patients with hypertensive nephrosclerosis (more common than ESKD), do not stop at blood pressure: ^[1]

• Cardiovascular risk reduction — statins and blood-pressure management are core elements of optimal CKD management.^[1]
• Treat albuminuria with an ACE inhibitor or ARB, and avoid potential nephrotoxins such as NSAIDs.^[1]
• Adjust drug dosing for kidney function (many antibiotics and oral hypoglycaemic agents) and monitor for CKD complications — hyperkalaemia, metabolic acidosis, hyperphosphataemia, vitamin D deficiency, secondary hyperparathyroidism and anaemia.^[1]
• Refer promptly to nephrology when eGFR is under 30, albuminuria is 300 mg per 24 hours or more, or eGFR is declining rapidly.^[1]

Non-pharmacological measures (lifestyle)

Hypertensive urgency (no acute end-organ damage)

Hypertensive urgency — severe BP without acute target-organ damage; several guidelines define the threshold as BP above 180/120 mm Hg, with hypertensive emergencies requiring the addition of target-organ damage.^[23] Guideline recommendations for urgency are inconsistent and expert-consensus based; outpatient treatment with oral medications and follow-up in days to weeks is most often advised.^[23] Beware rapid-acting regimens — oral clonidine, intravenous hydralazine and intravenous labetalol can cut SBP by over 80 mm Hg and MAP by over 25 percent within hours, beyond the approximate lower limit of cerebral autoregulation, which is why treatment guidelines warn against reductions of that size.^[26]

Specific Subtypes & Scenarios

Malignant-phase (accelerated) hypertension

A medical emergency. Histology: fibrinoid necrosis of arterioles + onion-skinning (hyperplastic arteriolitis) of interlobular arteries. Clinical triad: severe BP + retinopathy grade III–IV + AKI/MHA. Management: controlled IV BP lowering (labetalol, nicardipine) with the 25 percent MAP rule, admission to HDU/ICU, treatment of complications (pulmonary oedema, encephalopathy, AKI), and active search for an underlying secondary cause (high yield). After stabilisation, transition to an oral regimen including a RAAS blocker (with the expected early creatinine rise monitored).^[2]

Hypertensive urgency

Severe BP without acute target-organ damage; oral agents over 24–48 hours. The trap is mistaking an emergency (e.g., with subtle encephalopathy) for an urgency — when in doubt, treat as an emergency. ^[1]

Renovascular disease / renal artery stenosis

Two mechanisms: atherosclerotic (older patients with vascular disease; ostial lesions) and fibromuscular dysplasia (younger women; mid-artery 'string-of-beads'). Clues: flash pulmonary oedema, asymmetrical kidneys (over 1.5 cm difference), refractory hypertension, rising creatinine on an ACEi/ARB, abdominal bruit. Confirm with renal Doppler, CT or MR angiography. Medical therapy is first-line (RAAS blockade — paradoxically protective if unilateral disease; with caution if bilateral). Revascularisation (percutaneous angioplasty ± stent for atherosclerosis; angioplasty alone for FMD) is reserved for refractory hypertension, recurrent flash pulmonary oedema, rapidly declining renal function, or cardiac destabilisation — ASTRAL, STAR, and CORAL showed no routine benefit over medical therapy.^[1]

APOL1-mediated nephropathy

In people of recent West-African ancestry, the APOL1 G1/G2 risk variants confer a markedly increased risk of FSGS-like and hypertensive nephrosclerosis lesions with rapid progression to ESKD at a young age. There is no specific therapy yet (APOL1 inhibitors are in trials); management is maximal BP control with RAAS blockade, SGLT2 inhibition, and cardiovascular risk reduction.^[6]

Ischaemic nephropathy in the elderly

Diffuse atherosclerosis compromises renal perfusion; the kidney is an end-organ of systemic vascular disease. Manage with statin, antiplatelet, BP control, and avoid volume depletion and nephrotoxins. ^[1]

Complications & Pitfalls

Renal complications

• Progressive CKD culminating in ESKD requiring dialysis or transplantation.
• Acute kidney injury superimposed on chronic disease (acute-on-chronic) — triggered by volume depletion, NSAIDs, iodinated contrast, or starting an ACE inhibitor/ARB (especially with undiagnosed bilateral renovascular disease).
• Hyperkalaemia, metabolic acidosis, anaemia, and CKD–mineral and bone disorder (CKD-MBD) of advanced CKD. ^[1]

Cardiovascular complications — the leading cause of death

• Left ventricular hypertrophy, heart failure with preserved (HFpEF) or reduced (HFrEF) ejection fraction, ischaemic heart disease, atrial fibrillation, aortic dissection, and stroke. ^[1]

Complications specific to malignant-phase hypertension

• Hypertensive encephalopathy, intracerebral haemorrhage, acute pulmonary oedema, acute kidney injury, thrombotic microangiopathy with schistocytes and platelet consumption, retinal damage and blindness, and aortic dissection. ^[1]

Classic pitfalls (examiner favourites)

1. Lowering BP too rapidly in malignant-phase hypertension → ischaemic stroke, MI or AKI. Apply the 25 percent rule.
2. Missing a secondary cause in resistant or early-onset hypertension (renovascular disease, primary aldosteronism, phaeochromocytoma, OSA, coarctation).
3. Starting an ACE inhibitor/ARB in undiagnosed bilateral renal artery stenosis → precipitous AKI. Check creatinine and potassium at 1–2 weeks; a rise over 30 percent mandates stopping and investigating.
4. Using short-acting nifedipine capsules for hypertensive urgency → precipitous, uncontrolled BP fall, stroke/MI.
5. Attributing CKD to "just hypertension" when a glomerulonephritis or other treatable cause is present — always exclude active sediment and heavy proteinuria.
6. Failing to add an SGLT2 inhibitor in CKD — a now-standard, high-yield, evidence-based therapy.
7. Combining an ACE inhibitor with an ARB (ONTARGET: more renal harm, hyperkalaemia, hypotension, with no added benefit).
8. Prescribing an ACE inhibitor or ARB in pregnancy — fetopathy (renal agenesis, oligohydramnios, limb contractures, hypoplastic lungs). ^[1]

Prognosis & Disposition

Chronic hypertensive nephrosclerosis

Generally slowly progressive over years to decades with good blood-pressure control. The rate of eGFR decline is steepest in patients with proteinuria, poor BP control, coexisting diabetes, and APOL1 risk variants.^[6] Cardiovascular events, not ESKD, are the commonest cause of death — cardiovascular risk reduction is therefore as important as renal protection. With tight control (SBP under 120 per KDIGO 2021, RAAS blockade, SGLT2 inhibition) the slope of decline can be substantially slowed, though existing scarring is irreversible.

Malignant-phase hypertension

Untreated, historically near-universal mortality within months from uraemia, heart failure or stroke. With prompt, controlled BP lowering and management of complications, 5-year survival exceeds 70–80 percent, though many patients retain some degree of CKD and remain at high cardiovascular risk.^[2]

Disposition and follow-up

• Chronic disease: managed in primary care for uncomplicated cases, with nephrology referral when eGFR is under 30, proteinuria is heavy (UACR over 300), BP is resistant, or progression is rapid. Monitor BP, eGFR, UACR, and electrolytes every 3–12 months depending on CKD stage.
• Malignant-phase hypertension: admit to HDU/ICU; follow-up in a combined nephrology/hypertension clinic after discharge; address adherence and provide structured patient education.
• Safety-net and ESKD planning: when eGFR is under 20–25, begin renal replacement therapy education (transplantation, dialysis modalities, conservative care), vascular-access planning, and anaemia/CKD-MBD management. ^[1]

Special Populations

The elderly

Isolated systolic hypertension with a wide pulse pressure reflects stiff, atherosclerotic vasculature. Higher risk of orthostatic hypotension — always measure standing BP before intensifying therapy. SPRINT showed benefit of intensive control even in the over-75 subgroup, but exclude frailty and weigh falls risk. Prefer longer-acting, well-tolerated agents (amlodipine, an ACEi/ARB, a thiazide-like diuretic). ^[1]

Diabetes mellitus (the common coexisting disease)

Target BP under 130/80; begin with an ACE inhibitor/ARB if albuminuria is present (UACR over 30). Add an SGLT2 inhibitor (which also provides glycaemic and cardiovascular benefit — empagliflozin reduced cardiovascular death in EMPA-REG OUTCOME). Screen for diabetic retinopathy to help distinguish diabetic kidney disease from a pure hypertensive process. ^[1]

Pregnancy

Chronic hypertension is present in 0.9 to 1.5 percent of pregnancies and is associated with significant maternal, fetal and neonatal morbidity and mortality; its prevalence rose by two-thirds between 2000 and 2009, largely driven by the obesity epidemic and increasing maternal age.^[24] RAAS inhibitors are contraindicated in the second and third trimesters — fetopathy after gestational week 20 is well described, with fetopathy-consistent diagnoses in about 4 percent of RAAS-inhibitor-exposed newborns (11.5 percent of ARB-exposed) in a German cohort — and the antihypertensives recommended in pregnancy include metoprolol and methyldopa.^[27] Management follows a rational, evidence-based approach to defining, diagnosing and treating chronic hypertension in pregnancy.^[24]

Black / African ancestry

Higher hypertension prevalence, earlier onset, greater salt sensitivity, and APOL1-driven nephropathy. Emphasise early aggressive control, RAAS-based regimens (often combined with a CCB and/or thiazide), and dietary sodium reduction. ALLHAT showed that thiazide-type diuretics (chlorthalidone) and dihydropyridine CCBs are particularly effective initial agents in Black patients, but the AASK trial established that an ACE inhibitor (ramipril) slowed GFR decline better than amlodipine or metoprolol in African-Americans with hypertensive CKD — so an ACEi/ARB remains first-line in those with CKD or proteinuria, often with a CCB added.^[6][7]

Advanced chronic kidney disease

Switch the thiazide to a loop diuretic when eGFR is under 30; titrate doses of renally cleared drugs; continue SGLT2 inhibition down to eGFR 20; prepare for renal replacement therapy as eGFR declines; manage anaemia (iron, erythropoiesis-stimulating agents) and CKD-MBD. ^[1]

Evidence, Guidelines & Regional Differences

Landmark trials

Guidelines and regional differences

Controversies

• How low is too low? The very tight KDIGO target (SBP under 120) is not universally accepted; some bodies caution that orthostatic hypotension and AKI risk rise with very intensive lowering, especially in older or frail patients.
• APOL1-directed therapy — the first APOL1 inhibitors (e.g., inaxaplin) are in trials and may transform the management of APOL1-mediated disease.
• Renal artery stenosis — CORAL (NEJM 2014) confirmed no routine benefit of stenting over medical therapy, but selected subgroups (recurrent flash oedema, refractory hypertension, rapidly declining function) still warrant revascularisation.
• Renal denervation — modest, contested benefit in resistant hypertension; not routine. ^[1]

Exam Pearls

^{[1] [12] [6] [20] [9] [10] [15] [17] [1] [12] [14] [6] [20] [9] [10] [15] [17]}

Ward-round test

Three stems. Cover the answer, say it aloud, then reveal.^[1]

1. A 55-year-old man starts ramipril for hypertensive CKD. Two weeks later his creatinine has risen 35 percent and his potassium is 5.8. What must you do, and what are you looking for?^[1]
2. A 60-year-old arrives with a blood pressure of 220/130, papilloedema, confusion and a creatinine that has doubled. Why is "normalising the pressure quickly" the wrong instinct, and what is the rule?^[1][2]
3. A 70-year-old with CKD is already on ramipril and amlodipine to target. What class of drug, added regardless of diabetes, has changed the natural history of his kidney disease?^[9][10]

Ward-round answersShowHide

1. Stop the ACE inhibitor and screen for renovascular disease. An early creatinine rise up to 30 percent that stabilises within the first 2 months is acceptable and predicts long-term renal preservation; withdraw only if the rise exceeds 30 percent above baseline or potassium reaches 5.6 mmol/L or greater — and a rise of 50 percent or more within one week of starting therapy points to renovascular hypertension.^[20][17]
2. Malignant hypertension is a hypertensive emergency with autoregulation failure — BP must be lowered within hours, but in a controlled fashion: reduce mean arterial pressure by no more than 25 percent in the first hour, then to 160/100-110 mm Hg over 2-6 hours, with subsequent gradual normalisation over 24-48 hours.^[14][15]
3. An SGLT2 inhibitor — dapagliflozin or empagliflozin 10 mg once daily. DAPA-CKD and EMPA-KIDNEY showed a 28 to 39 percent reduction in kidney failure or cardiovascular death across CKD, including in non-diabetic patients, on top of RAAS blockade.^[9][10]

^[1]

References27ShowHide

1. [1]Chen TK, Knicely DH, Grams ME. Chronic Kidney Disease Diagnosis and Management: A Review JAMA, 2019.PMID 31573641
2. [2]Romagnani P, Remuzzi G, Glassock R, et al. Chronic kidney disease Nat Rev Dis Primers, 2017.PMID 29168475
3. [3]Whelton PK, Carey RM, Aronow WS, et al. 2017 ACC/AHA/AAPA/ABC/ACPM/AGS/APhA/ASH/ASPC/NMA/PCNA Guideline for the Prevention, Detection, Evaluation, and Management of High Blood Pressure in Adults: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines Hypertension, 2018.PMID 29133356
4. [4]Williams B, Mancia G, Spiering W, et al. 2018 Practice Guidelines for the management of arterial hypertension of the European Society of Hypertension and the European Society of Cardiology: ESH/ESC Task Force for the Management of Arterial Hypertension J Hypertens, 2018.PMID 30379783
5. [5]Wright JT Jr, Williamson JD, Whelton PK, et al. A Randomized Trial of Intensive versus Standard Blood-Pressure Control N Engl J Med, 2015.PMID 26551272
6. [6]Wright JT Jr, Bakris G, Greene T, et al. Effect of blood pressure lowering and antihypertensive drug class on progression of hypertensive kidney disease: results from the AASK trial JAMA, 2002.PMID 12435255
7. [7]ALLHAT Officers and Coordinators for the ALLHAT Collaborative Research Group. Major outcomes in high-risk hypertensive patients randomized to angiotensin-converting enzyme inhibitor or calcium channel blocker vs diuretic: The Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT) JAMA, 2002.PMID 12479763
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9. [9]Heerspink HJL, Stefánsson BV, Correa-Rotter R, et al. Dapagliflozin in Patients with Chronic Kidney Disease N Engl J Med, 2020.PMID 32970396
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11. [11]Levey AS, Bosch JP, Lewis JB, Greene T, Rogers N, Roth D. (MDRD Study Group). A more accurate method to estimate glomerular filtration rate from serum creatinine: a new prediction equation. Modification of Diet in Renal Disease Study Group Ann Intern Med, 1999.PMID 10075613
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20. [20]Bakris GL, Weir MR. Angiotensin-converting enzyme inhibitor-associated elevations in serum creatinine: is this a cause for concern? Arch Intern Med, 2000.PMID 10724055
21. [21]Jamerson K, Weber MA, Bakris GL, et al. Benazepril plus amlodipine or hydrochlorothiazide for hypertension in high-risk patients N Engl J Med, 2008.PMID 19052124
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