Mitral inflow patterns after MitraClip implantation at rest and during exercise

Area of Science:

• Cardiology
• Interventional Cardiology
• Echocardiography

Background:

• MitraClip implantation effectively reduces mitral regurgitation but can cause iatrogenic mitral stenosis.
• Transesophageal echocardiography (TEE) is crucial for intraprocedural assessment of mitral regurgitation and mitral valve pressure gradient (MVPG).
• Accurate hemodynamic assessment is vital for deciding on additional clip placement and ensuring procedural safety.

Purpose of the Study:

• To determine if intraprocedural hemodynamic measurements accurately reflect postprocedural measurements.
• To assess the impact of MitraClip-induced stenosis on exercise capacity.
• To evaluate the correlation between MVPG, systolic pulmonary artery pressure (sPAP), and heart failure symptoms post-procedure.

Main Methods:

• Retrospective single-center study of 51 patients undergoing MitraClip implantation.
• Intraprocedural TEE and postprocedural transthoracic echocardiography (TTE) for hemodynamic measurements.
• Exercise echocardiography performed in 23 patients to assess hemodynamics under stress.

Main Results:

• Postprocedural mean MVPG (4.3 ± 2.2 mm Hg) was significantly higher than intraprocedural measurements (3.0 ± 1.6 mm Hg).
• Exercise significantly increased mean MVPG (3.6 ± 1.7 to 6.3 ± 2.7 mm Hg).
• Patients with resting MVPG ≥ 5 mm Hg had higher sPAPs, but no increase in heart failure symptoms was observed.

Conclusions:

• Intraprocedural TEE underestimates daily-life MVPG and exercise hemodynamics after MitraClip.
• Pressure half-time is a robust parameter for assessing mitral stenosis severity and guiding clip decisions.
• Elevated post-MitraClip MVPG and sPAP do not necessarily correlate with increased heart failure symptoms.