What guides decision making for aortic surgery in acute and chronic aortic regurgitation?

Decision Making for Aortic Surgery in Acute and Chronic Aortic Regurgitation

Surgical decision making for aortic regurgitation (AR) is guided primarily by symptom status, left ventricular function, ventricular dimensions, and aortic root pathology, with urgent intervention required for acute severe AR and a more measured approach for chronic AR.

Acute Severe Aortic Regurgitation

Acute severe AR represents a surgical emergency with clear decision-making criteria:

• Urgent/emergent surgical intervention is indicated for all patients with symptomatic acute severe AR 1
• Immediate surgical management is critical as acute AR causes sudden increases in left ventricular volume leading to pulmonary edema and hypotension 2
• Delaying surgery in acute AR can result in rapid hemodynamic deterioration and death

Chronic Severe Aortic Regurgitation

Decision making for chronic AR follows a more structured approach based on symptoms, LV function, and dimensions:

Symptomatic Patients

• Surgery is indicated in all symptomatic patients with severe AR (Class I, Level B) 1
• This includes patients with dyspnea (NYHA class II-IV) or angina 1
• Surgery should not be denied even in symptomatic patients with LV dysfunction or marked LV dilatation 1

Asymptomatic Patients

Decision making follows this algorithm:

1. Surgery is indicated in asymptomatic patients with severe AR and:

   • Resting LVEF ≤50% (Class I, Level B) 1
   • Patients undergoing CABG or surgery of ascending aorta or another valve (Class I, Level C) 1

2. Surgery should be considered in asymptomatic patients with severe AR and:

   • Normal LVEF (>50%) but severe LV dilatation (Class IIa, Level C) 1:
     • LVEDD >70 mm
     • LVESD >50 mm (or >25 mm/m² BSA)

3. Additional factors that should prompt consideration for surgery:

   • Rapid worsening of ventricular parameters on serial testing 1
   • Exercise-induced symptoms revealed through stress testing 3

Aortic Root Disease Considerations

For patients with aortic root disease, regardless of AR severity:

1. Surgery is indicated when maximal ascending aortic diameter is:

   • ≥50 mm for patients with Marfan syndrome (Class I, Level C) 1

2. Surgery should be considered when maximal ascending aortic diameter is:

   • ≥45 mm for patients with Marfan syndrome with risk factors (family history of dissection, aortic size increase >2 mm/year, severe AR/MR, pregnancy desire) 1
   • ≥50 mm for patients with bicuspid valve with risk factors (coarctation, hypertension, family history of dissection) 1
   • ≥55 mm for other patients 1

3. Lower thresholds apply when:

   • Patient requires surgery on the aortic valve for other reasons 1
   • Valve repair is likely and performed in an experienced center 1

Common Pitfalls in Surgical Decision Making

1. Delaying surgery until symptoms develop can result in irreversible LV damage 4

   • Regular monitoring is essential: every 6-12 months for severe AR with normal LVEF
   • Every 1-2 years for moderate AR, every 3-5 years for mild AR 4

2. Failing to adjust thresholds for patient size

   • Lower threshold values should be considered for patients of small stature 4
   • Indexing measurements to BSA is helpful in these cases 1

3. Missing concomitant aortic root disease

   • Patients with aortic root disease may require earlier intervention 4
   • Consider the shape and thickness of the ascending aorta as well as the shape of other parts of the aorta 1

4. Overlooking rapid progression

   • Aortic diameter increase >2 mm/year is a risk factor requiring earlier intervention 1
   • Serial measurements using the same imaging technique are essential 1

Surgical Considerations

• Operative mortality is low (1-3%) in asymptomatic patients undergoing isolated aortic valve surgery 1
• Mortality increases (3-7%) in symptomatic patients, combined aortic valve and root surgery, and concomitant CABG 1
• Strongest predictors of poor outcomes: advanced age, higher preoperative functional class, LVEF <50%, and LVESD >50 mm 1
• Valve repair may be considered in selected patients with favorable anatomy at experienced centers 4

By following these evidence-based guidelines, clinicians can optimize timing of surgical intervention to prevent irreversible myocardial damage and improve long-term outcomes for patients with aortic regurgitation.