How to manage a patient with uncontrolled hypertension and worsening microalbuminuria?

Management of Uncontrolled Hypertension with Worsening Microalbuminuria

Adding a thiazide diuretic to the current regimen is the most appropriate next step for this patient with uncontrolled hypertension and worsening microalbuminuria. 1

Current Clinical Situation

The patient presents with:

• Uncontrolled hypertension (BP 140/95 mmHg) despite maximum doses of perindopril (8mg) and amlodipine (10mg)
• Worsening microalbuminuria (ACR increased from 2.6 to 6.2 mg/mmol; albumin from 23 to 89 mg/L)
• Normal renal function (eGFR >90)
• HbA1c of 39 mmol/mol (pre-diabetic range)

Treatment Algorithm

Step 1: Optimize RAAS Blockade

• The patient is already on maximum dose of perindopril (4mg × 2 tablets)
• ACE inhibitors are first-line therapy for patients with microalbuminuria 2, 1

Step 2: Add Thiazide Diuretic

• Since BP remains uncontrolled on maximum doses of ACE inhibitor and calcium channel blocker, add a thiazide diuretic 1, 3
• Thiazide diuretics are particularly effective when combined with RAAS blockers and CCBs for resistant hypertension 3

Step 3: Consider ARB Substitution if No Response

• If BP control remains suboptimal after adding a thiazide diuretic, consider switching from ACE inhibitor to ARB 2, 1
• Both ACE inhibitors and ARBs are effective in reducing microalbuminuria 2

Target Blood Pressure

• Target BP should be <130/80 mmHg for this patient with microalbuminuria 2, 1
• This more aggressive target is appropriate given the evidence of target organ damage (microalbuminuria) 2

Rationale for Treatment Approach

1. Microalbuminuria Significance:

   • Microalbuminuria indicates glomerular filtration barrier damage and predicts progression to overt nephropathy 2
   • It's a potent predictor of future cardiovascular events and mortality 2
   • Worsening microalbuminuria (as in this patient) signals progressive kidney damage 2

2. RAAS Blockade:

   • ACE inhibitors and ARBs delay progression of nephropathy in patients with microalbuminuria 2
   • The patient is already on maximum dose of perindopril (ACE inhibitor)

3. Thiazide Diuretic Addition:

   • Adding a thiazide diuretic is recommended when BP remains uncontrolled on maximum doses of RAAS blocker and CCB 1, 3
   • Thiazide diuretics complement the action of RAAS blockers and CCBs in resistant hypertension 3

4. Continuing Statin:

   • Continue simvastatin despite normal lipid levels as statins provide renal and cardiovascular protection 1

Monitoring Plan

1. Short-term Follow-up:

   • BP review in 4 weeks as planned is appropriate
   • Monitor serum creatinine and potassium 1-2 weeks after adding thiazide diuretic 1

2. Long-term Follow-up:

   • Repeat urine ACR and renal function in 6 months as planned
   • Annual screening for microalbuminuria thereafter 2, 1

Lifestyle Modifications

• Reinforce importance of:
  • Increased water intake (patient reported low water intake)
  • Low sodium diet (sodium restriction <2,300 mg/day) 1
  • Regular exercise
  • Medication adherence (consider morning dosing instead of night dosing given afternoon work shifts)

Cautions and Pitfalls

1. Avoid Dual RAAS Blockade:

   • Do not combine ACE inhibitor with ARB as this increases risk of hyperkalemia without additional benefit 2, 1

2. Monitor for Hyperkalemia:

   • Adding a thiazide diuretic may help mitigate hyperkalemia risk from RAAS blockade 1

3. Transient Creatinine Rise:

   • A slight increase in serum creatinine (up to 20%) may occur with intensified antihypertensive therapy but should not be taken as a sign of progressive renal deterioration 2

4. Pre-diabetic Status:

   • Monitor HbA1c as thiazide diuretics may worsen glycemic control
   • Current HbA1c of 39 mmol/mol indicates pre-diabetes, requiring close monitoring

By implementing this treatment approach, the goal is to achieve optimal blood pressure control (<130/80 mmHg) and reduce microalbuminuria, thereby slowing the progression of kidney damage and reducing cardiovascular risk.