Persistent diastolic dysfunction late after valve replacement in severe aortic regurgitation.

Area of Science:

• Cardiology
• Cardiac Surgery
• Cardiovascular Research

Background:

• Left ventricular (LV) hypertrophy and diastolic dysfunction are common in chronic aortic regurgitation.
• Previous studies show regression of LV hypertrophy after aortic valve replacement (AVR) in aortic stenosis.
• The impact of AVR on LV function and structure in aortic regurgitation requires further evaluation.

Purpose of the Study:

• To assess the early and late effects of AVR on LV function and structure in patients with chronic aortic regurgitation.

Main Methods:

• Eleven patients with severe aortic regurgitation underwent LV biplane angiograms, pressure measurements, and endomyocardial biopsies before and after AVR (21 and 89 months).
• LV systolic function (ejection fraction, midwall fractional shortening) and diastolic function (relaxation time constant, peak filling rates, stiffness constant) were evaluated.
• LV structure was assessed via muscle fiber diameter, interstitial fibrosis, and fibrous content.

Main Results:

• LV muscle mass significantly decreased by 55% late after AVR.
• LV relaxation normalized late after AVR, while ejection fraction remained unchanged.
• Diastolic stiffness remained elevated post-AVR, and interstitial fibrosis decreased late after surgery.

Conclusions:

• AVR leads to normalization of macroscopic LV hypertrophy in aortic regurgitation patients.
• However, persistent fiber hypertrophy and diastolic dysfunction are observed late after AVR.
• These structural changes correlate with altered passive elastic properties and persistent diastolic dysfunction.