Aortic Coarctation

Introduction

Stenosis of the descending aorta
(in the area of ligamentum arteriosum)

    • Rare in desc or abdominal aorta
    • Usually discrete (sometimes aortic hypoplasia)
  • Majority distal to L-subclavian
  • Pathophysiology (proposed)
    • Cells in the PDA migrate to the aorta.
    • After birth, cells exposed to high pO2 (sVO2 is 70% in utero), causing cytokine activation
    • Results in narrowing/closure of the PDA and aorta
  • Associated with Turner’s Syndrome
    (+Bicuspid Aortic Valve)
  • “Aortopathy”
    • Intima abnormal in entire aorta, and it is
    • Susceptible to dissection/dilation (not just coarct site)

Classification

  • Types (Pediatrics)
    • Pre-Ductal (worse, relies on PDA, once PDA closes, circulation is compromised)
    • Juxta-Ductal
    • Post-Ductal (better b/c develops collaterals in-utero)
  • Types:
    • Simple: No other cardiac lesions (50%)
    • Complex: associated with other lesions (50%)

Associations

  • Bicuspid Aortic Valve (80%) = worse outcomes! (aortic syndromes)
  • Berry (intracranial) aneurysms of the circle of Willis (3-5%)
  • Brachiocephalic anomalies (5%)
    • I.e. anomalous origin of R-subclavian
  • Collaterals
    • Anterior –> IMA
    • Posterior –> Intercostal Arteries
  • VSD

Presentation / History

  • Symptoms: (often absent)
    • Headaches
    • Exertional Leg Fatigue
  •  Vitals
    • Upper limb hypertension
    • Differential arm-leg pulses
  • Incidental Murmur
  • Severe Presentation:
    • Heart Failure (30-40yo) (28%)
    • Aortic rupture/dissection (21%)
    • Cerebral Hemorrhage (12%)
    • Premature CAD
    • Aortic Valve Disease

Diagnosis

Physical Exam

  • Blood Pressure –> Upper & Lower Limb (>20 sBP differential)
  • Cardiac
    • Systolic murmur LSE–> continuous
    • Collaterals cause murmurs radiate to back
    • 4th sound w/ LVH & HTN
    • Loud A2 if hypertension
    • Ejection click (bicuspid AoV)
  • Delayed femoral pulses
    • Radio-femoral delay

ECG

  • Left Ventricular Hypertrophy
Coarctation ECH (LVH)

Chest Xray

  • A ‘3-sign’ (Classic, but rare)
    • indentation of the aorta at coarctation
    • post-stenotic dilation
  • Dilation before and after coarctation
  • ‘rib notching’ caused by erosion of inferior rib border of posterior ribs due to large intercostal collaterals
Chest Xray Coarctation

Echocardiogram

  • Screening:
  • ***Diastolic runoff of abdominal Aorta doppler***
  • Suprasternal arch view is the best for identifying anatomic coarctation
  • Rarely can be seen in the PA window (mostly in pediatrics)

Management

  • Workup:
    • ECG, Chest Xray, Echo
    • MRI is very important (aneurysms/collaterals etc..)
    • CTA/MRA of head! (berry aneurysms)
    • Cath –> gradient (can treat percutaneously)
      • Significant Aortic Coarctation
        • Peak pull back gradient of > 20 mmhg across coarctation site on angiography
          OR
        • Peak pullback > 10 mmHg and collaterals
          (Canadian guidelines don’t define cutoff if collaterals present)

Indications for repair

  • Surgical vs. percutaneous
    • (Generally percutaneous is preferred unless additional problems coexist)
  • Surgical Techniques:
    • End-to-end anastomosis (preferred)
    • Subclavian flap aortoplasty (children – supply to arm may be compromized)
    • Dacron patch
    • Tube graft
AHA 2018 Guidelines
Indications for Repair (AHA 2018)
  • Hypertesion + Significant native/recoarctation (Class I)

  • “Significant native/recurrent coarctation”:
    • Anatomic coarctation (CTA/MRA) AND
      • Upper-lower peak-peak >20 mmHg or mean doppler systolic > 20 mmHg
        OR
      • Upper-Lower peak-peak > 10 mmHg or mean doppler > 10mmHg +
        • Decreased LVEF
        • AR
        • Collateral Flow
Indications for Repair (Canadian 2008)
CachNet Guidelines 2018 (Canada)
  • “All patients with significant coarctation/recoarctation … whether symptomatic or asymptomatic warrant intervention”

Ongoing Care (Post-Op)

  • Surgery is NOT a cure
    • Remember: Aortopathy!
    • 80% have HTN (AHA 2018) at 30y
    • Surgival is LOWER than population (30y survival 72%)
    • Age of repair predicts survival (< 20yo survival better but not normal)
  • Need lifelong cardiology follow-up
  • Premature death due to:
    • Coronary Artery Disease
    • Heart Failure
    • Stroke
  • Post-Repair Complications:
    • Re-Coarctation
    • Dacron patch aneurysms
    • Aortic emergencies (dissection/aneurysm/rupture)
  • New HTN must be treated aggressively with GDMT
    • Exclude re-coarctation
    • B-blockers often quoted first line
  • Screen for HTN with exercise/rest/ambulatory (AHA 2018)
  • MRI Head q5-10 years (Class IIB)
    • (10% have aneurysms – AHA 2018)
    • Cannot MRI if has a aortic stent
  • Follow-up aortic imaging CTA/MRA post-repair  (some say q5-10y) (Class I)
  • Ambulatory 24-hr BP monitor can be useful (Class IIA)
  • Exercise BP testing if patient exercises (Class IIB)

References

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