What is the best course of action for a patient with a history of stroke and carotid artery (CA) stenosis, who has uncontrolled hypertension (HTN) with a blood pressure (BP) of 192/86, and may have underlying renal artery stenosis, after missing a day of antihypertensive medication?

Management of Uncontrolled Hypertension in High-Risk Patient with Medication Non-Adherence

The immediate priority is to address medication adherence and optimize the current antihypertensive regimen before pursuing workup for renal artery stenosis, as this patient's BP of 192/86 after missing one day of medication suggests inadequate baseline control rather than an acute hypertensive emergency requiring hospitalization. 1

Immediate Blood Pressure Management

• Do not aggressively lower BP acutely in this patient with a history of stroke and carotid stenosis, as rapid reduction risks cerebral hypoperfusion and ischemic injury 2
• The current BP of 192/86, while severely elevated, does not constitute a hypertensive emergency requiring IV therapy since there are no symptoms of acute target organ damage 1, 3
• Gradually reduce BP over several days to weeks through optimization of oral antihypertensive therapy rather than immediate aggressive reduction 1
• Avoid reducing BP by more than 10-15% in the first 24 hours in patients with cerebrovascular disease to prevent watershed infarction 2

Addressing Medication Adherence

The single missed day of medication causing this degree of BP elevation strongly suggests the current regimen is inadequate for sustained control. 4

• Reinforce the critical importance of daily medication adherence, particularly given her stroke history and carotid stenosis 2
• Consider simplifying to once-daily dosing and single-pill combinations to improve adherence 2
• Implement home BP monitoring with self-measurement to enhance patient engagement and treatment adherence 2

Optimizing Antihypertensive Therapy

This patient requires intensification of therapy given uncontrolled BP despite current treatment. 2

Recommended Medication Algorithm:

• Add a thiazide-like diuretic (preferably chlorthalidone over hydrochlorothiazide) if not already prescribed, as this is highly effective for resistant hypertension 5
• Ensure the regimen includes an ACE inhibitor or ARB given her history of stroke and cardiovascular disease 2, 5
• Add a calcium channel blocker if not already part of the regimen to create guideline-recommended triple therapy 5
• Target BP should be <140/90 mmHg with reassessment within 2-4 weeks after medication adjustment 2, 5

If BP Remains Uncontrolled on Triple Therapy:

• Add spironolactone 25-50 mg daily as the preferred fourth-line agent for resistant hypertension, which provides significant additional BP reduction (average 25/12 mmHg) 2, 5
• Alternative fourth-line agents if spironolactone is not tolerated include eplerenone, amiloride, or doxazosin 2

Evaluation for Renal Artery Stenosis

The workup for renal artery stenosis should be pursued systematically but is not the immediate priority before optimizing medical therapy. 2, 6

Indications Supporting Further Workup:

• History of carotid stenosis increases the likelihood of atherosclerotic renal artery stenosis, as these conditions commonly coexist 6
• Resistant hypertension despite optimized triple therapy is a key indication for screening 2, 7
• The presence of unexplained renal dysfunction or worsening creatinine (>20 μmol/L increase) during ACE inhibitor/ARB therapy would strengthen the indication 7

Diagnostic Approach:

• Renal artery ultrasound is a reasonable initial non-invasive screening test as suggested by the provider's note 2
• However, functional testing with nuclear medicine differential GFR before and after ACE inhibitor/ARB administration is more specific for identifying hemodynamically significant stenosis 6
• Renal angioplasty with stenting may be considered only if hemodynamically significant stenosis (≥70% or 50-69% with post-stenotic dilatation) is confirmed AND the patient has resistant hypertension despite maximally tolerated medical therapy 2

Important Caveats:

• Do not avoid ACE inhibitors/ARBs due to fear of acute renal failure in suspected renal artery stenosis—this complication occurs in <5% of patients and is reversible with revascularization 6
• Renal angioplasty is not recommended without confirmed hemodynamically significant stenosis 2
• Medical therapy remains the cornerstone of treatment even when renal artery stenosis is present 6, 7

Monitoring Plan

• Reassess BP within 1-2 weeks after medication adjustment 2
• Achieve target BP within 3 months of treatment modification 2, 5
• Monitor renal function (creatinine, eGFR) 1-2 weeks after starting or increasing ACE inhibitor/ARB dose 7
• If BP remains uncontrolled despite optimized four-drug therapy including spironolactone, refer to hypertension specialist 2

Key Clinical Pitfalls to Avoid

• Do not pursue renal artery stenosis workup before optimizing medical therapy, as medication non-adherence and suboptimal regimens are far more common causes of uncontrolled BP 4, 7
• Avoid rapid BP reduction in patients with cerebrovascular disease, as this increases stroke risk 2
• Do not use short-acting nifedipine for acute BP lowering due to unpredictable rapid drops 2
• Do not hospitalize for asymptomatic severe hypertension without evidence of acute target organ damage 1