Geometric Changes in Mitral Valve Apparatus during Long-term Cardiac Resynchronization Therapy as Assessed with...

Area of Science:

• Cardiovascular Imaging and Intervention
• Cardiac Electrophysiology

Background:

• Cardiac resynchronization therapy (CRT) is used to treat heart failure patients with electrical dyssynchrony.
• Long-term effects of CRT on the mitral valve apparatus geometry are not fully understood.

Purpose of the Study:

• To evaluate long-term geometric alterations of the mitral valve apparatus after CRT using cardiac CT.
• To assess the correlation between these geometric changes and left ventricular (LV) volumes and function.

Main Methods:

• Prospective follow-up cardiac CT examinations in participants of a randomized controlled trial (NCT01323686).
• Assessment of mitral valve annulus area, A2 leaflet angle, tenting height, and interpapillary muscle distances.
• Correlation analysis between geometric changes and LV volumes/function using Pearson correlation test.

Main Results:

• Significant reductions observed in end-systolic A2 leaflet angle, tenting height, and interpapillary muscle distances after a median of 9 years post-CRT.
• Mitral valve annulus area remained unchanged.
• Interpapillary muscle distance changes correlated with decreased LV volumes and improved LV ejection fraction; A2 leaflet angle and tenting height did not.

Conclusions:

• Long-term CRT leads to favorable geometric remodeling of the mitral valve apparatus, particularly reduced interpapillary muscle distances.
• The correlation between reduced interpapillary muscle distances and improved LV volumes suggests a potential mechanism for CRT benefit.
• A2 leaflet angle and tenting height changes were not significantly associated with LV volume changes post-CRT.