Left atrial strain as a pre-operative prognostic marker for patients with severe mitral regurgitation

•In severe mitral regurgitation (MR), optimal surgical timing should be recognized.•Preoperative left atrial strain could be useful to assess prognosis after MR surgery.•LA reservoir strain was a good predictor of clinical and functional outcome in MR.•LA reservoir strain was also correlated with LA fibrosis assessed by atrial biopsy.