Introduction
Left atrial (LA) strain is a novel parameter to assess LA function and may help guide the management of mitral valve (MV) disease. We evaluated LA strain and volume in patients with MV prolapse with various degrees of mitral regurgitation (MR) as well as their change over several years of follow-up.
Methods
This retrospective analysis included outpatients with MV prolapse on transthoracic echocardiography and at least two follow up echocardiograms. Digital loops were acquired from apical four chamber views. For assessment of LA strain, recordings were processed with acoustic-tracking software allowing offline semi-automated speckle-based strain analyses with enddiastolic reference. Additionally, LA volume (LAV) and left ventricular ejection fraction (LVEF) were obtained and severity of MR was determined through standard parameters.
Results
The study comprised 30 patients (10 female; mean age at first presentation 52y ± 17) The mean time follow-up interval was 29 months. At baseline, mean LVEF was 59% and 12 patients had mild, 15 patients moderate and 3 patients severe MR. There was a significant decline in LA strain and significant increase in LAV during follow-up: median baseline LA strain 32% (IQR 8.3%), median LA strain at follow-up 24% (IQR 6%; p < 0.01); mean LAV at baseline 63.6 ml (± 21.8), mean LAV at follow-up 78.8 ml (± 26.9; p < 0.01). Correlation between LA strain and LAV was only modest (r = -0.43, p = 0.02 for baseline examination; r = -0.52, p < 0.01; for follow-up examination). At follow-up, progress in MR severity was found only in 3 patients (from mild to moderate), even though 9 patients displayed an increase in vena contracta (VC) width which did not affect grading of MR severity. In all visits, mitral VC width correlated more closely with LAV (r ranging from 0.48 to 0.53; p < 0.03) than LA strain (r ranging from -0.3 to -0.4; p < 0.03 and p = 0.1).
Conclusion
On intermediate follow-up, we could demonstrate a significant increase of LAV and decrease in LA strain in patients with MV prolapse with varying degrees of mitral regurgitation. Further research is needed to evaluate the prognostic impact of these parameters and their value for clinical decision making in mitral valve prolapse patients.
