Diagnosis and Management of Resistant Hypertension Related to Coarctation of the Aorta
All patients with a history of coarctation repair who develop resistant hypertension must be evaluated for residual or recurrent aortic arch obstruction with CT angiography or cardiac MRI, and if a significant gradient is confirmed invasively (peak-to-peak >20 mmHg), surgical or catheter-based intervention should be pursued. 1
Diagnostic Approach
Initial Clinical Assessment
Measure blood pressure in both arms and at least one lower extremity to detect the characteristic upper-to-lower extremity gradient that defines hemodynamically significant coarctation. 1, 2, 3 This is the single most important bedside diagnostic maneuver.
On physical examination, specifically assess for:
- Diminished or delayed femoral pulses compared to brachial pulses 1
- A systolic murmur over the back (interscapular region) 1
- Blood pressure differential: upper extremity hypertension with lower extremity hypotension 1
Confirming True Resistant Hypertension
Before attributing hypertension to coarctation, confirm true treatment resistance using 24-hour ambulatory blood pressure monitoring to exclude white-coat hypertension, which accounts for approximately 50% of apparent resistant cases. 4 The patient should be on maximally tolerated doses of at least 3 antihypertensive agents including a renin-angiotensin system blocker, long-acting calcium channel blocker, and appropriate diuretic. 4
Imaging to Define Coarctation Anatomy
CT angiography or cardiac MRI of the entire thoracic aorta is mandatory for all patients with suspected coarctation-related resistant hypertension. 1, 2, 3 These imaging modalities will:
- Define the exact location and severity of coarctation (>50% narrowing is significant) 2, 3
- Identify residual or recurrent obstruction after prior repair 1, 5
- Detect collateral vessels 2
- Screen for aneurysms or pseudoaneurysms (ascending or descending aorta) 1, 2
- Assess for associated bicuspid aortic valve 2, 3
Hemodynamic Confirmation
A non-invasive arm-to-leg systolic gradient >20 mmHg (mean) or >35 mmHg (peak) suggests hemodynamically significant coarctation. 3 However, invasive catheterization with direct pressure measurement remains the gold standard, with a peak-to-peak gradient >20 mmHg confirming the need for intervention. 1, 2, 3
Treatment Strategy
Indications for Intervention
Intervention is indicated when hypertension (>140/90 mmHg in adults) is present along with:
- An invasive peak-to-peak gradient >20 mmHg, OR 1, 2, 3
50% aortic narrowing relative to the diameter at the diaphragm level (even if gradient <20 mmHg) 2
Even normotensive patients with invasive gradient >20 mmHg should be considered for intervention to prevent future cardiovascular complications. 2
Choice of Intervention
Transcatheter treatment with covered stent placement is the first-choice treatment for adults and older children (>25 kg) with native or recurrent coarctation. 2, 3, 6 This approach is preferred over surgery when technically feasible. 1, 2
Balloon angioplasty without stenting may be considered only if stent placement is not feasible and surgery is not an option, though it carries higher recurrence rates and risk of aneurysm formation. 2
Medical Management of Hypertension
β-blockers are the most useful first-line agents because persistent hypertension after coarctation repair is often secondary to increased sympathetic tone. 1
Antihypertensive therapy should also include an ACE inhibitor or ARB as standard second-line therapy. 1, 6 This combination addresses both the sympathetic overactivity and renin-angiotensin system activation that characterize post-coarctation hypertension.
Diuretic therapy should be optimized based on renal function: thiazide-like diuretics are effective down to eGFR 30 mL/min/1.73m², with loop diuretics reserved for eGFR <30 mL/min/1.73m². 4
Critical Pitfalls to Avoid
Do not assume that prior coarctation repair in childhood eliminates the diagnosis—recurrence can occur decades later, even in patients over 70 years old. 5 Patients with operated coarctation have lifelong elevated blood pressure burden and exaggerated BP response to exercise. 1
Do not rely solely on office blood pressure measurements—24-hour ambulatory monitoring or exercise testing better detects hypertension in coarctation patients. 2, 3
Do not overlook associated conditions: Screen for bicuspid aortic valve dysfunction and ascending aortic dilation, which commonly coexist with coarctation. 2, 3 Consider screening for intracranial aneurysms by MRA or CTA, particularly in patients with family history or neurological symptoms. 2, 3
Lifelong Surveillance Requirements
All coarctation patients require lifelong follow-up regardless of treatment success, with CT angiography or cardiac MRI every 3-5 years to monitor for re-coarctation, aneurysms, pseudoaneurysms, and dissection. 1, 2, 3 Patients with repaired coarctation remain at elevated risk for myocardial infarction, aortic aneurysm, stroke, and heart failure throughout their lifetime. 1, 7
Hypertension should be treated according to standard guidelines with aggressive blood pressure targets to reduce the lifetime cardiovascular disease burden. 1, 2, 3