Comparison of myocardial mechanics after mitral valve repair with leaflet preservation versus leaflet resection: A subanalysis of the randomized Canadian Mitral Research Alliance CardioLink-2 trial.

BACKGROUND

Previous studies comparing leaflet resection versus leaflet preservation for surgical repair of mitral regurgitation caused by prolapse have focused predominately on measurement of left ventricular ejection fraction without adjusting for loading conditions. This post hoc subanalysis evaluated subclinical differences in myocardial mechanics before mitral valve repair, immediately after, and 1 year after repair, as well as differences between leaflet resection and preservation strategies.

METHODS

A total of 104 patients were randomized to the resection or preservation group for surgical treatment of posterior leaflet prolapse in the Canadian Mitral Research Alliance CardioLink-2 study. Speckle-tracking echocardiography was performed at baseline (prerepair), immediately postrepair, and 1-year postrepair. Global longitudinal strain (GLS) was compared at the 3 time points, as well as between leaflet preservation and resection groups using descriptive statistics. GLS was adjusted for left ventricular (LV) end-diastolic dimensions to adjust for loading conditions.

RESULTS

The mean (standard deviation) age of the participants was 65 ± 10 years, and 83% were male. The mean GLS before mitral valve repair was -19.6% ± 5.4% and did not differ between the leaflet resection and leaflet preservation groups. The mean GLS decreased to -12.8% ± 4.7 immediately postrepair (P = .001 compared with prerepair). At 1-year after repair, the mean GLS improved to -16% ± 4% in both groups but remained below prerepair values; however, the GLS indexed to loading conditions was similar to preoperative values. Preoperative GLS was an independent predictor of postoperative reduced GLS independent of age, sex, body surface area, and repair strategy.

CONCLUSIONS

Mitral valve repair is associated with an immediate reduction in GLS, but when corrected for loading conditions, indexed GLS demonstrates complete preservation of LV function at 1 year. The leaflet preservation and resection techniques for surgical repair of mitral regurgitation have similar effects on myocardial mechanics 1-year postrepair. Preoperative GLS may be used to predict LV myocardial mechanics 1-year postoperatively (Trial registration number NCT02552771, https://clinicaltrials.gov/study/NCT02552771).