Value of quantitative analysis of mitral regurgitation jet eccentricity by color flow Doppler for identification of flail leaflet

Early surgical intervention improves the outcome of patients with mitral regurgitation (MR) secondary to flail leaflet. Current criteria for the diagnosis of flail leaflet require a detailed definition of mitral valve anatomy, which is often challenging by transthoracic echocardiography (TTE) and, occasionally, even by transesophageal echocardiography (TEE). We studied 57 patients (mean age 63 ± 15 years) with anatomically confirmed flail mitral leaflet and a control group of 57 patients (mean age 68 ±14 years) with at least moderate MR but no flail leaflet. In patients with flail mitral leaflet, the mean angle formed by the axis of the MR jet and the plane of the mitral annulus was 33 ± 11° and 29 ± 16° when measured with TTE and TEE, respectively. In controls the mean angle was 66 ± 16° and 66 ± 17° by TTE and TEE, respectively (p <0.0001). Based on receiver- operating characteristic analysis, the optimal cutoff jet angle value for diagnosing flail mitral leaflet was 45° with TTE (sensitivity 88%, specificity 88%), and 47° by TEE (sensitivity 88%, specificity 88%). MR jet angles ≤45° were also correctly identified by visual assessment of TTE images in >90% of cases, with good interobserver agreement (k = 0.76). Thus, quantitative analysis of MR jet eccentricity by color flow Doppler is highly sensitive and specific for diagnosing flail mitral leaflet.