Length of second-order chordae as a predictor of systolic anterior motion of the mitral valve.

OBJECTIVES: The aim of the present study was to ascertain whether the length of anterior mitral leaflet second-order chordae (SOC) could be considered as a predictor of the incidence of post-repair systolic anterior motion (SAM) and left ventricular outflow tract obstruction (LVOTO) in patients with myxomatous mitral valve disease.

METHODS: With the implementation of preoperative transoesophageal echocardiography (TEE), the length of anterior mitral leaflet SOC, anterior leaflet (AL) and posterior leaflet (PL) as well as the distance from the coaptation point to the septum (C-S distance) before and after mitral valve repair (MVR) surgery were measured in 190 patients, comprising 12 who developed SAM and 178 who did not.

RESULTS: The results revealed that, in patients who developed SAM, SOC were significantly higher (2.76 ± 0.15 vs 1.83 ± 0.32 mm, P < 0.001) and the C-S distance was significantly lower (2.18 ± 0.36 vs 2.91 ± 0.36 mm, P < 0.001) in comparison to the obtained results for those who did not develop SAM. SOC and the C-S distance were independent risk factors of developing SAM and had the largest area under the receiver operating characteristic (ROC) curve (P < 0.001). With application of a cut-off ROC curve analysis, the cut-offs selected for the two variables of C-S distance and SOC were 2.5 and 2.6, respectively. Sensitivity and specificity of SAM development were 100% [95% confidence interval (CI): 73.5-100] and 87.1% (95% CI: 81.0-91.4) for SOC ≥2.6 and 83.3% (95% CI: 51.6-97.9) and 73.6% (95% CI: 66.4-79.9) for the C-S distance ≤2.5.

CONCLUSIONS: The two variables of the second-order chordae and the distance from the coaptation point to the septum were associated with an increased risk of the post-repair systolic anterior motion after mitral valve repair.