How to manage a patient with aortic stenosis undergoing non-cardiac surgery?

Management of Aortic Stenosis in Non-Cardiac Surgery

Patients with severe aortic stenosis should undergo aortic valve replacement before elective non-cardiac surgery if they are symptomatic, unless they are at high risk for valve surgery, in which case TAVI or balloon aortic valvuloplasty should be considered as a bridge to surgery. 1

Risk Assessment

• Clinical and echocardiographic evaluation is mandatory for all patients with known or suspected aortic stenosis scheduled for intermediate or high-risk non-cardiac surgery 1
• Severe aortic stenosis is defined as valve area <1.0 cm², indexed valve area ≤0.6 cm²/m², maximum jet velocity ≥4 m/s, or mean gradient ≥40 mm Hg 1
• Severe aortic stenosis constitutes a well-established risk factor for perioperative mortality and myocardial infarction 1
• Patients with severe aortic stenosis who refuse cardiac surgery face approximately 10% mortality risk when undergoing non-cardiac procedures 2, 3

Management Algorithm Based on Symptoms and Surgical Risk

For Symptomatic Patients with Severe AS:

• Aortic valve replacement is recommended before elective non-cardiac surgery if the patient is not at high risk for valve surgery 1
• For patients at high risk for valve surgery who need non-cardiac surgery, TAVI or balloon aortic valvuloplasty should be considered as a bridge 1
• If urgent non-cardiac surgery is required, proceed with more invasive hemodynamic monitoring 1

For Asymptomatic Patients with Severe AS:

• Low to intermediate-risk non-cardiac surgery can be performed safely without prior intervention 1
• For high-risk non-cardiac surgery, aortic valve replacement should be considered if the patient is not at high risk for valve surgery 1
• If high-risk for valve replacement, elective surgery should be performed only if strictly necessary and with invasive hemodynamic monitoring 1

Perioperative Management

• Maintain sinus rhythm and avoid tachycardia, which can decrease diastolic filling time and coronary perfusion 4
• Avoid hypotension through careful fluid management and prompt use of vasopressors (phenylephrine preferred) 4, 3
• Avoid myocardial depression from anesthetic agents 4
• Implement invasive arterial monitoring for all cases involving severe AS 3, 5
• Consider intensive care unit monitoring postoperatively, even if the patient appears stable 1

Common Pitfalls and Caveats

• Rapid changes in volume status can precipitate hemodynamic collapse in patients with severe AS - maintain euvolemia 1, 4
• Beta-adrenergic agonists should be avoided as they may worsen hemodynamics in AS 1
• Tachycardia must be avoided as it reduces diastolic filling time and coronary perfusion 4
• The risk of non-cardiac surgery in patients with AS may be overestimated based on older studies that predate modern anesthetic techniques and perioperative care 6, 7
• Intraoperative hypotension requiring vasopressor use is more common in patients with severe AS (30% vs 17% in controls) and requires prompt, aggressive treatment 8

Special Considerations

• For patients with prosthetic valves, the main challenge is perioperative anticoagulation management 1
• Patients with severe mitral stenosis and pulmonary artery pressure >50 mmHg may benefit from percutaneous mitral commissurotomy before high-risk surgery 1
• When valve surgery is needed before non-cardiac surgery, a bioprosthesis is preferred to avoid anticoagulation issues during subsequent non-cardiac surgery 1

By following this evidence-based approach to managing patients with aortic stenosis undergoing non-cardiac surgery, clinicians can minimize perioperative morbidity and mortality while ensuring optimal patient outcomes.