Mitral Regurgitation Part 3: Surgical Management and Hemodynamic Considerations

Types of Surgical Interventions¹

• MV repair vs. replacement: In patients with severe MR for whom surgery is indicated, MV repair is preferred to replacement if the cause of MR is degenerative valvular disease. Decisions regarding repair and replacement are complex, and patients are often evaluated by a multidisciplinary team.
• Transcatheter edge-to-edge mitral repair (TEER) can be offered to patients with severe symptomatic primary MR if the risk of open repair is high or prohibitive due to other medical comorbidities. TEER may also be offered to patients with severe secondary MR who remain symptomatic despite optimal GDMT.
• Transcatheter mitral valve replacement (TMVR) utilizes transcatheter aortic valves that are implanted in the mitral position for patients with bioprosthetic dysfunction (Valve-in-Valve or Valve-in-Ring) or severe mitral annular calcifications (Valve-in-MAC). This intervention can be employed using either a minimally invasive or open approach.

Perioperative Considerations²

• Open surgical mitral repair or replacement may be performed via traditional median sternotomy or via a minimally invasive right thoracotomy approach. The latter approach requires lung isolation and may be associated with hypoxemia, given that the patient is not in the left lateral decubitus position (resulting in worse V/Q mismatch).
• In addition to standard American Society of Anesthesiologists monitors, continuous invasive arterial blood pressure monitoring is warranted. A pulmonary artery catheter may be considered in patients with reduced left ventricular (LV) function, significant pulmonary hypertension, or those undergoing complex operations (e.g., redo sternotomy, multiple valves, coronary artery bypass grafting).
• TEER and TMVR are typically performed in cardiac catheterization labs or hybrid rooms, under general anesthesia, with continuous transesophageal echocardiography and fluoroscopic guidance. These patients are often of advanced age and carry multiple comorbidities. Pre-induction arterial line and large-bore peripheral access are warranted, given the risk of cardiac chamber perforation with transcatheter interventions. Central access may be considered if postoperative vasoactive support is anticipated.

Hemodynamic Management²

• The overall goal of hemodynamic management for a patient with MR during general anesthesia is to optimize forward flow and minimize the regurgitant volume; this can be done with relative tachycardia and reduced afterload.
• Heart rate goal: Relative tachycardia to avoid worsening MR
  • Bradycardia increases regurgitant volume by increasing time in diastole and LV filling. This causes the left ventricle to overfill, which distends the mitral annulus and worsens the regurgitation.
• Contractility goal: Maintain to ensure adequate cardiac output
  • Inodilators (e.g., milrinone, dobutamine) are preferred as they have the added advantage of reducing afterload. Afterload reduction increases forward flow. Increases in afterload will increase regurgitation fraction and reduce cardiac output.
• Preload goal: Euvolemia to maintain cardiac output
  • Maintain preload to support cardiac output.
  • Avoid volume overload, which may worsen regurgitation, pulmonary edema, and contribute to further dilation of the left ventricle.
• Afterload goal: Reduce afterload to augment forward flow
  • Treat hypertension with vasodilators as needed.
  • Decreases in afterload during induction may be advantageous in augmenting forward flow, but must be balanced with the need to maintain coronary perfusion.