3.1 Hypertension Canada 2020/2025 Guidelines, Dyslipidemia, & Primary Prevention

3.1 Hypertension Canada 2020/2025 Guidelines, Dyslipidemia, & Primary Prevention

Quick Summary: In non-diabetic patients, hypertension is diagnosed when Automated Office Blood Pressure (AOBP) is ≥135/85 mmHg, manual office BP is ≥140/90 mmHg, or out-of-office ABPM 24-hour average is ≥130/80 mmHg. In diabetic patients, the diagnostic and treatment target threshold is strictly <130/80 mmHg. First-line therapies comprise thiazide/thiazide-like diuretics (chlorthalidone/indapamide), ACE inhibitors, ARBs, or dihydropyridine CCBs. High-risk cardiovascular patients according to CCS dyslipidemia guidelines require high-intensity statin therapy to achieve an LDL-C target <1.8 mmol/L.

Diagnostic Criteria & Blood Pressure Thresholds

Hypertension Canada guidelines emphasize Automated Office Blood Pressure (AOBP) as the preferred in-office measurement method. AOBP uses an automated oscillometric device taking 5 sequential unobserved readings while the patient rests quietly alone in an examination room. This significantly attenuates the white-coat effect compared to standard manual auscultatory office blood pressure measurement.

Diagnostic Workflow & Out-of-Office Confirmation

When an initial office BP reading is elevated, out-of-office BP measurement via 24-hour Ambulatory Blood Pressure Monitoring (ABPM) or Home Blood Pressure Monitoring (HBPM) is mandatory before establishing a definitive diagnosis, unless the patient presents with severe hypertension (SBP ≥180 mmHg or DBP ≥110 mmHg) or hypertensive target organ damage (e.g., left ventricular hypertrophy, retinopathy, nephropathy).

1. White-Coat Hypertension: Elevated office BP (≥135/85 AOBP) with normal out-of-office readings (ABPM daytime <135/85 or HBPM <135/85). Reassess annually; drug therapy is not routinely indicated.
2. Masked Hypertension: Normal office BP (<135/85 AOBP) with elevated out-of-office readings (ABPM daytime ≥135/85 or HBPM ≥135/85). Carries cardiovascular risk equivalent to sustained hypertension and requires pharmacotherapy.
3. Hypertensive Urgency vs. Emergency:
   • Hypertensive Urgency: Severe BP elevation (typically SBP >180 mmHg or DBP >110 mmHg) without acute target organ damage. Managed with oral agents (e.g., amlodipine, labetalol, captopril) and outpatient follow-up within 24 to 48 hours.
   • Hypertensive Emergency: Severe BP elevation with acute, progressive end-organ damage (e.g., hypertensive encephalopathy, acute aortic dissection, acute coronary syndrome, acute pulmonary edema, eclampsia, or acute renal failure). Requires immediate ICU admission and IV antihypertensives (e.g., labetalol, nicardipine, hydralazine, or sodium nitroprusside). Target: reduce SBP by no more than 25% within the first hour, then to 160/100 mmHg over 2 to 6 hours (Exception: Acute aortic dissection requires immediate SBP reduction to <120 mmHg within 20 minutes).

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Pharmacological Management of Hypertension

Initial Monotherapy vs. Single-Pill Combination Therapy

First-line monotherapy agents according to Hypertension Canada include:

• Thiazide / Thiazide-like Diuretics: Long-acting thiazide-like diuretics (Chlorthalidone 12.5–25 mg daily or Indapamide 1.25–2.5 mg daily) are preferred over hydrochlorothiazide (HCTZ) due to proven cardiovascular endpoint reduction and longer half-lives.
• ACE Inhibitors (ACEi): Ramipril, perindopril, enalapril. (Monitor serum potassium and creatinine; expect up to a 30% rise in creatinine which is acceptable if stable).
• Angiotensin Receptor Blockers (ARBs): Valsartan, telmisartan, losartan, candesartan.
• Long-Acting Dihydropyridine CCBs: Amlodipine, nifedipine XL.

Note: Beta-blockers (e.g., atenolol, metoprolol) are not recommended as first-line initial monotherapy in uncomplicated hypertension for patients aged 60 years or older due to inferior stroke prevention and all-cause mortality reduction compared to other first-line agents.

Single-Pill Combination Therapy: If initial SBP is ≥20 mmHg above target or DBP is ≥10 mmHg above target, initiating treatment with a single-pill combination of two first-line agents (e.g., ACEi/ARB + CCB, or ACEi/ARB + Thiazide-like diuretic) is strongly recommended to accelerate BP control and improve compliance.

Regimens for Specific Comorbid Conditions

• Diabetes Mellitus with Renal Disease (ACR >2.0 mg/mmol or eGFR <60 mL/min): ACEi or ARB is mandatory first-line therapy to slow diabetic nephropathy progression.
• Heart Failure with Reduced Ejection Fraction (HFrEF): Quad therapy: ARNI (Sacubitril/Valsartan) or ACEi/ARB + Beta-blocker (Bisoprolol, Carvedilol, Metoprolol Succinate) + MRA (Spironolactone/Eplerenone) + SGLT2 inhibitor (Dapagliflozin/Empagliflozin).
• Stable Ischemic Heart Disease: ACEi or ARB + Beta-blocker ± Dihydropyridine CCB.
• Pregnancy (Chronic/Gestational Hypertension or Preeclampsia): Labetalol, Methyldopa, or Long-acting Nifedipine are first-line. ACE inhibitors, ARBs, and direct renin inhibitors are strictly contraindicated in pregnancy due to fetotoxicity (renal dysgenesis, oligohydramnios, skull hypoplasia).

Secondary Hypertension Screening

Secondary hypertension should be suspected in young patients (<30 years), abrupt onset, resistant hypertension (uncontrolled despite 3 drugs including a diuretic at optimal doses), or sudden loss of BP control.

1. Renal Parenchymal Disease: Most common secondary cause overall. Diagnosed via urinalysis, ACR, and renal ultrasound.
2. Primary Aldosteronism (Conn Syndrome): Most common endocrine secondary cause. Suspect if unprovoked hypokalemia or resistant HTN. Screen with Aldosterone-to-Renin Ratio (ARR) while off MRAs.
3. Renovascular Hypertension (Renal Artery Stenosis): Fibromuscular dysplasia in young females; atherosclerotic RAS in older males. Clues: flash pulmonary edema, abdominal bruit, >30% rise in serum creatinine after initiating ACEi/ARB. Test: Renal Doppler US or CCTA.
4. Pheochromocytoma: Triad of episodic headache, sweating, and tachycardia. Test: 24-hour plasma or urinary fractionated metanephrines.
5. Obstructive Sleep Apnea (OSA): Resistant nocturnal HTN, snoring, daytime somnolence. Test: Polysomnography.

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Dyslipidemia Management (CCS 2021 Guidelines)

The Canadian Cardiovascular Society (CCS) dyslipidemia guidelines advocate a risk-stratified, target-driven approach to primary and secondary prevention of atherosclerotic cardiovascular disease (ASCVD).

Risk Stratification & Statin-Indicated Conditions

Patients are risk-stratified using the 10-year Framingham Risk Score (FRS): Low (<10%), Intermediate (10–19%), High (≥20%). However, patients meeting any of the following Statin-Indicated Conditions are automatically categorized as High Risk and require statin therapy regardless of FRS:

• Clinical ASCVD (MI, ACS, Stable Angina, Stroke, TIA, Peripheral Artery Disease)
• Abdominal Aortic Aneurysm (AAA >3.0 cm or prior repair)
• Diabetes Mellitus (Age ≥40, OR Age <40 with diabetes duration >15 years or microvascular complications)
• Chronic Kidney Disease (Age ≥50 with eGFR <60 mL/min/1.73m² or ACR >3.0 mg/mmol)
• Severe Hypercholesterolemia (Baseline LDL-C ≥5.0 mmol/L, suggesting Familial Hypercholesterolemia)

Therapeutic Targets & Escalation Strategy

• High-Risk / Statin-Indicated Target: Achieve LDL-C <1.8 mmol/L OR ≥50% reduction in baseline LDL-C; alternate targets: ApoB <0.7 g/L, Non-HDL-C <2.6 mmol/L.
• Intermediate-Risk Target (FRS 10–19%): Initiate statin if baseline LDL-C ≥3.5 mmol/L, ApoB ≥1.0 g/L, or Non-HDL-C ≥4.2 mmol/L. Statin therapy is also recommended if high-risk features are present (e.g., hsCRP >2.0 mg/L, Coronary Artery Calcium [CAC] score >0, or family history of premature CAD).
• First-Line Therapy: High-intensity statins (Atorvastatin 40–80 mg daily or Rosuvastatin 20–40 mg daily).
• Second-Line Escalation: Add Ezetimibe 10 mg daily if LDL-C target is unmet on maximum tolerated statin dose.
• Third-Line Escalation: Add PCSK9 Inhibitors (Evolocumab or Alirocumab SC) for secondary prevention or heterozygous familial hypercholesterolemia if LDL-C remains elevated despite maximal statin + ezetimibe.

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Primary Prevention & Lifestyle Interventions

• Dietary Modification: The DASH (Dietary Approaches to Stop Hypertension) diet—rich in vegetables, fruits, whole grains, and low-fat dairy products, with reduced saturated and total fat—lowers SBP by 8–14 mmHg.
• Sodium Restriction: Reduce elemental sodium intake to <2000 mg daily (<5 g salt/day).
• Physical Activity: 150 minutes per week of moderate-to-vigorous aerobic physical activity in sessions of 10 minutes or more.
• Alcohol Moderation: ≤2 standard drinks/day for men (max 10/week), ≤1 standard drink/day for women (max 5/week).
• ASA for Primary Prevention: Routine acetylsalicylic acid (ASA 81 mg daily) is not recommended for primary cardiovascular prevention due to major gastrointestinal and intracranial bleeding risks outweighing ischemic benefits. ASA remains mandatory for secondary prevention in established ASCVD.