Usefulness of Computed Tomography to Predict Mitral Stenosis After Transcatheter Mitral Valve Edge-to-Edge Repair.

Multidetector computed tomography (MDCT) can provide valuable information for preprocedural planning of transcatheter mitral valve interventions. However, no data exists on pre-MDCT parameters predicting high transmitral pressure gradient (TMPG) post-MitraClip procedure. We analyzed the preprocedural MDCTs of 156 consecutive patients with mitral regurgitation undergoing MitraClip implantation at our institution. The mean TMPG was assessed by periprocedural transesophageal and pre-discharge transthoracic echocardiography. MDCT-derived mitral annulus area (MAA), anterior-posterior (AP) and medial-lateral (ML) mitral annulus diameters, and mitral valve orifice area (MVOA) were smaller in patients with mean TMPG ≥5 mmHg than those with mean TMPG <5 mmHg after 1-or 2-clip implantation. Small MAA, AP and ML diameters, and MVOA were moderately correlated with high TMPG post-MitraClip, in which MAA and MVOA had the highest degree of correlation after 1-clip (r = -0.46 both), whereas MAA and ML had the strongest degree of correlation after 2-clip (r = -0.39 both) and at discharge (r = -0.38 both). From the receiver-operating-characteristic curve analyses, no significant differences in the area under the curve were observed among these MDCT parameters for low TMPG after MitraClip implantation, except for those between MAA and AP diameter at discharge (p=0.026). For optimal cutoff values, MAA ≥1100 and ≥1300 mm2 had positive predictive values of 89% and 91%, while both MAA ≥750 and ≥900 mm2 had negative predictive values of 100%, for mean TMPG <5 mmHg after 1-and 2-clip implantation, respectively. In conclusion, in patients undergoing the MitraClip procedure, preprocedural MDCT parameters are useful to predict postprocedural mitral stenosis.