What is the recommended initial management and treatment approach for a Canadian patient diagnosed with hypertension, considering potential comorbidities such as cardiovascular disease or diabetes?

Initial Management and Treatment of Hypertension in Canadian Patients

Confirm the Diagnosis First

Before initiating any treatment, confirm hypertension with out-of-office measurements: home blood pressure monitoring ≥135/85 mmHg or 24-hour ambulatory monitoring ≥130/80 mmHg. 1

• Use validated automated upper arm cuff devices with appropriate cuff size, measuring blood pressure in both arms and consistently using the arm with higher readings 1
• Office blood pressure ≥140/90 mmHg defines hypertension but must be confirmed with home or ambulatory monitoring to rule out white coat hypertension 1

Immediate Lifestyle Modifications for All Patients

All patients should begin comprehensive lifestyle modifications immediately, which can reduce blood pressure by 10-20 mmHg and are essential regardless of whether pharmacotherapy is initiated. 2

Dietary Interventions

• Sodium restriction to <1,500 mg/day (65 mmol/day) for adults ≤50 years, 1,300 mg/day (57 mmol/day) for ages 51-70, and 1,200 mg/day (52 mmol/day) for those >70 years 3
• Follow a DASH diet emphasizing 8-10 servings of fruits and vegetables daily, 2-3 servings of low-fat dairy products, whole grains, and reduced saturated/trans fats 2, 4
• Increase dietary potassium to 3,500-5,000 mg/day through food sources 1

Physical Activity

• Perform 30-60 minutes of moderate aerobic exercise 4-7 days per week 1, 5

Weight Management

• Maintain body mass index 18.5-24.9 kg/m² and waist circumference <102 cm for men, <88 cm for women 1, 5

Alcohol Limitation

• Limit alcohol to ≤14 standard drinks per week for men or ≤9 per week for women 1, 3

Pharmacological Treatment Algorithm

When to Start Medication

For patients with diabetes, chronic kidney disease, or established cardiovascular disease: start pharmacologic therapy immediately alongside lifestyle modifications. 2

For stage 2 hypertension (≥140/90 mmHg): initiate pharmacologic therapy immediately in addition to lifestyle modifications. 2

For stage 1 hypertension without high-risk conditions: implement lifestyle modifications for a maximum of 3 months; if blood pressure targets are not achieved, start pharmacologic therapy. 2

First-Line Medication Selection

The preferred initial approach is two-drug combination therapy as a single-pill combination: low-dose ACE inhibitor or ARB + dihydropyridine calcium channel blocker. 2

For Non-Black Patients Without Comorbidities:

• Start with ACE inhibitor (e.g., lisinopril 10 mg once daily) or ARB (e.g., losartan 50 mg once daily) 1, 6, 7
• Alternative first-line options include thiazide diuretics, long-acting calcium channel blockers, or beta-blockers (if age <60 years) 8, 3

For Black Patients:

• Start with ARB plus dihydropyridine calcium channel blocker, or alternatively calcium channel blocker plus thiazide-like diuretic 1
• ACE inhibitors are less effective as monotherapy in Black patients 8

Treatment Based on Comorbidities

For patients with diabetes and albuminuria (urine albumin-to-creatinine ratio ≥30 mg/g): ACE inhibitor or ARB is mandatory as first-line treatment. 9, 2

For patients with chronic kidney disease: ACE inhibitor or ARB at maximum tolerated dose, especially with albuminuria. 9, 2

For patients with heart failure with reduced ejection fraction: guideline-directed medical therapy beta-blockers plus ACE inhibitor or ARB plus diuretic. 9, 2

For patients with coronary artery disease or post-myocardial infarction: beta-blockers plus ACE inhibitor or ARB. 9, 3

For patients with cerebrovascular disease: ACE inhibitor plus thiazide diuretic combination. 9, 8

Blood Pressure Targets

Target blood pressure <130/80 mmHg for patients with diabetes, chronic kidney disease, or established cardiovascular disease. 2

Target blood pressure <140/90 mmHg minimum for all other patients. 2, 8, 3

• The initial goal should be to reduce blood pressure by at least 20/10 mmHg 2

Treatment Intensification Strategy

If blood pressure remains uncontrolled on two medications, add a thiazide or thiazide-like diuretic to complete triple therapy (ACE inhibitor/ARB + calcium channel blocker + thiazide diuretic). 10, 2

• Chlorthalidone 12.5-25 mg daily is preferred over hydrochlorothiazide due to longer duration of action and superior cardiovascular outcomes 10, 2
• Most patients require more than one agent to achieve blood pressure targets 2, 8

If blood pressure remains uncontrolled on optimized triple therapy, add spironolactone 25-50 mg daily as the preferred fourth-line agent for resistant hypertension. 10

Monitoring Strategy

Follow-up approximately monthly for dose titration until blood pressure is controlled. 9, 1

• Target blood pressure should be achieved within 3 months of initiating treatment 2
• Check serum creatinine and potassium 7-14 days after starting or adjusting ACE inhibitors, ARBs, or mineralocorticoid receptor antagonists 2
• Once controlled, recheck blood pressure every 3-6 months 2

Critical Pitfalls to Avoid

Never combine an ACE inhibitor with an ARB—this increases adverse events (hyperkalemia, acute kidney injury) without additional cardiovascular benefit. 10, 3

Do not add a beta-blocker as third-line therapy unless there are compelling indications (angina, post-MI, heart failure with reduced ejection fraction, or heart rate control). 10

Do not delay treatment intensification in patients with stage 2 hypertension—prompt action is required to reduce cardiovascular risk. 10

Verify medication adherence before escalating therapy, as non-adherence is the most common cause of apparent treatment resistance. 10

When to Refer to Specialist

Refer to a hypertension specialist if blood pressure remains uncontrolled on 3 or more medications (resistant hypertension) or if secondary causes of hypertension are suspected. 1