Left atrial strain by cardiac MRI feature tracking in mitral stenosis before and after balloon valvuloplasty

The aim was to investigate LA strain by feature tracking cardiac MRI in mitral stenosis (MS) patients before and after percutaneous balloon mitral valvuloplasty (PBMV). Patients underwent cardiac MRI before and after successful PBMV (n = 18). Mitral valve area, transmitral velocity and gradients, LA volumes and ejection fraction (LAEF) were measured. LA strain feature tracking analysis was used to calculate LA reservoir, conduit, and booster strain. LA strain, LA volumes, LAEF and mitral valve severity indices were compared before and after PBMV. Correlations between LA strain and other cardiac MRI parameters were assessed. After PBMV, mitral valve area increased from 1.18 ± 0.25 cm² to 2.26 ± 0.27 cm², p < 0.001. Transmitral peak velocity decreased from 1.7 ± 0.37 m/s to 1.3 ± 0.27 m/s, p < 0.001. Transmitral peak gradient decreased from 12.4 ± 4.8 mmHg to 6.8 ± 2.9 mmHg, p < 0.001, and mean gradient decreased from 6.9 ± 3.8 mmHg to 2.9 ± 1.4 mmHg, p < 0.001. Maximal LA volume decreased from 73.1 ± 14.2 ml/m² to 62.7 ± 16.3 ml/m², p = 0.018; corrected p value = 0.054. LAEF increased from 36.3 ± 8.7% to 44.4 ± 9.5%, p = 0.010. Reservoir strain increased from 11.7 ± 3.1% to 14.9 ± 3.6% after PBMV, p = 0.009, and conduit strain from 3.8 ± 2% to 6 ± 2.3%, p = 0.005. Booster strain insignificantly increased after PBMV. Cardiac MRI feature tracking provides information on the 3 LA functional phases. Significant improvement was observed in reservoir and conduit functions after successful PBMV.