Impact of Aortic Valve Replacement on Mitral Stenosis

Pathophysiological Mechanism

When aortic valve replacement (AVR) is performed in a patient with concurrent mitral stenosis, the left ventricular (LV) afterload is reduced, which can lead to hyperdynamic LV function with increased ejection fraction, according to the European Society of Cardiology 1, 2
This hyperdynamic state increases cardiac output and blood flow velocity, forcing more blood volume through the stenotic mitral valve at higher velocities, as reported by the European Journal of Heart Failure 3
The increased flow across a fixed mitral valve orifice results in higher transmitral pressure gradients according to the fluid dynamics principle that pressure gradient is proportional to the square of flow velocity, as stated by the European Heart Journal 4, 5

Higher transmitral gradients will exacerbate left atrial pressure elevation, potentially leading to worsening pulmonary hypertension, as noted by the European Heart Journal 5
Higher transmitral gradients will also increase the risk of pulmonary edema, according to the European Heart Journal 4
Atrial enlargement and higher risk of atrial fibrillation can occur due to increased transmitral gradients, as reported by the European Heart Journal 5

For patients with significant mitral stenosis (valve area <1.5 cm²) and planned aortic valve surgery, consideration should be given to addressing both valves during the same procedure, as recommended by the European Heart Journal 4, 5
In symptomatic patients or those with pulmonary artery pressure >50 mmHg, correction of mitral stenosis should be attempted before or simultaneously with aortic valve intervention, according to the European Heart Journal 5
Percutaneous mitral commissurotomy (PMC) is an option for mitral stenosis treatment in suitable valve anatomy, as stated by the European Heart Journal 5

The severity threshold for intervention in mitral stenosis may need to be lowered when concurrent aortic valve disease is present, especially if hyperdynamic LV function is anticipated after AVR, as noted by the American Heart Association 6, 5
Heart rate control is particularly important in mitral stenosis patients after AVR, as tachycardia will further reduce diastolic filling time and worsen hemodynamics, according to the European Heart Journal 5
Careful fluid management is essential in the perioperative period to prevent volume overload and pulmonary edema, as recommended by the American Heart Association 6, 5

Close echocardiographic monitoring is essential after AVR in patients with residual mitral stenosis to assess transmitral gradients and pulmonary artery pressures, as stated by the European Heart Journal 5
Early intervention for worsening mitral stenosis may be necessary if clinical deterioration occurs following AVR, according to the European Heart Journal 5

Underestimating the impact of increased cardiac output on mitral stenosis hemodynamics, as warned by the European Heart Journal 4, 5
Failing to recognize that even moderate mitral stenosis can become hemodynamically significant in the setting of hyperdynamic LV function, as noted by the European Heart Journal 5
Inadequate rate control in patients with atrial fibrillation, which can dramatically worsen mitral stenosis symptoms after AVR, according to the European Heart Journal 5