What is the management of aortic insufficiency (aortic regurgitation) with anesthesia?

From the Guidelines

Management of aortic insufficiency during anesthesia requires careful hemodynamic control to maintain forward cardiac output and avoid worsening regurgitation, with a focus on maintaining a relatively high heart rate, normal to slightly elevated systemic vascular resistance, and adequate preload while avoiding bradycardia and extreme hypertension. The anesthetic approach should be tailored to the individual patient's needs, taking into account the severity of the aortic insufficiency and any underlying cardiac disease. According to the 2020 ACC/AHA Guideline for the Management of Valvular Heart Disease 1, patients with significant aortic regurgitation undergoing noncardiac surgery had a higher in-hospital mortality rate and higher morbidity rate, including postoperative myocardial infarction, stroke, pulmonary edema, intubation >24 hours, and major arrhythmias, than those of case-matched controls without aortic regurgitation.

Key considerations in the management of aortic insufficiency during anesthesia include:

• Maintaining a relatively high heart rate (80-100 beats per minute) to reduce diastolic time and regurgitant volume
• Avoiding bradycardia, which can prolong diastole and increase regurgitant volume
• Maintaining normal to slightly elevated systemic vascular resistance to reduce the pressure gradient driving retrograde flow across the aortic valve
• Maintaining adequate preload to ensure optimal cardiac output
• Avoiding extreme hypertension, which can increase the pressure gradient driving retrograde flow across the aortic valve

Induction can be performed with etomidate (0.2-0.3 mg/kg) or carefully titrated propofol, combined with fentanyl (2-3 mcg/kg) or remifentanil infusion (0.05-0.2 mcg/kg/min) 1. Maintenance can include volatile anesthetics at 0.5-1.0 MAC, which provide some afterload reduction. Phenylephrine (50-200 mcg boluses or 0.1-0.5 mcg/kg/min infusion) is preferred for hypotension rather than ephedrine, which can cause tachycardia and worsen regurgitation. Invasive monitoring with arterial line and possibly central venous pressure or pulmonary artery catheter is recommended for moderate to severe aortic insufficiency. Transesophageal echocardiography can be valuable for assessing ventricular function and regurgitation severity.

The 2014 ACC/AHA Guideline on Perioperative Cardiovascular Evaluation and Management of Patients Undergoing Noncardiac Surgery 2 also provides guidance on the management of patients with valvular heart disease, including aortic insufficiency, undergoing noncardiac surgery. However, the 2020 ACC/AHA Guideline for the Management of Valvular Heart Disease 1 is more recent and provides more specific guidance on the management of aortic insufficiency during anesthesia.

From the Research

Management of Aortic Insufficiency with Anesthesia

• The management of patients with aortic insufficiency depends on the severity of the valve lesion and the acuity with which it develops 3.
• Medical therapy, including vasodilator therapy, can be used to improve long-term outcomes in patients with aortic insufficiency 3, 4.
• Sodium nitroprusside has been shown to be effective in the management of patients with severe acute aortic insufficiency, and its effect can be monitored by noninvasive means 5.
• The use of vasodilators, such as hydralazine, calcium-channel blockers, and angiotensin-converting enzyme inhibitors, can improve hemodynamic and structural parameters in asymptomatic patients with chronic aortic insufficiency, but the impact on clinical outcomes is uncertain 4.
• Aortic valve replacement is a surgical option for patients with severe aortic insufficiency, and the optimal timing for valve replacement depends on various factors, including the severity of the valve lesion and the patient's symptoms 6.

Anesthetic Considerations

• Patients with aortic insufficiency require careful anesthetic management to prevent exacerbation of the condition 7.
• The use of anesthetics that reduce systemic vascular resistance, such as sodium nitroprusside, can be beneficial in patients with aortic insufficiency 7, 5.
• However, the effects of anesthetics on ventricular function parameters, such as end-systolic elastance and end-systolic volume at zero pressure, must be carefully considered to avoid adverse effects 7.