1. Patients (Fig. 3)

◦ Retrospective review of medical records and cardiac CT scan

◦ Inclusion

  - Patients who underwent MV annuloplasty from Jan 1995 to Dec 2013

     AND

  - Patients who underwent cardiac CT from Mar 2008 to Aug 2014

◦ Exclusion

 -Patient with interval less than 1 year between CT and MV annuloplasty (n=13)

 - Patients with rheumatic heart disease (n=6)

 - Patients with no ring or other ring types (n=3)

 - Patients with non-assessable CT image quality (n=2)

◦ A total of 45 patients were included in the final analysis

Fig. 3: A flow diagram of the study population.

2. CT Image analysis

◦ Multiplanar reformatted images in a short-axis image of the MV annulus, a long-axis view of the left ventricle, and a 4-chamber view

◦Pannus formation, valve leaflet thickening, valve opening area, diastolic opening angle, and systolic coaptation angles of anterior and posterior mitral leaflets, tenting height and mitral annular size (Fig. 4)

Fig. 4: Parameters for CT image analysis.

◦ Pannus formation around the annuloplasty ring 

  - Using short axis view of the mitral annulus

  - Severity of pannus:  both qualitative and quantitative methods (Fig. 5)

◦ Leaflet thickeness

  - Both qualitative and quantitative methods (Fig. 5)

  - Leaflet thickening: the maximal thickness of the MV leaflet >2mm 

Fig. 5: Details for the assessment of pannus severity and leaflet thickening on CT.

◦ The opening area of the MV

- In cases in which multiphase data were available

- Measured at the maximal opening point of the valve tip

◦ The diastolic opening angle and systolic coaptation angles of the anterior    and posterior mitral leaflets and the tenting height on systole

 - 4-chamber view

◦ Assessment of mitral ring size

 - The maximal and minimal diameters inside the annuloplasty ring

 - The annular area

 - The annular sphericity index: The maximal annular diameter/ minimal diameter

3. Data analysis

◦ Clinical data

 - Etiology of original valve disease, type and size of annuloplasty ring, concurrent other valve operation or coronary artery bypass graft surgery, and follow-up data for reoperation

◦ Transthoracic echocardiography (TTE) data

- Mean diastolic PG (MDPG), MV area (MVA, by pressure half time), presence of mitral regurgitation, and left ventricular ejection fraction

4. Statistical analysis

◦ Correlation between TTE parameter (PG, PHT)and CT appearance (pannus, leaflet thickening) 

  - Pearson correlation coefficient

◦ Comparison of CT findings between patients with normal PG and patients with elevated PG (mean-diastolic PG≥ 5mmHg) 

◦ Comparison of incidence of functional MS on TTE, presence of pannus, and leaflet thickening on CT between the two ring types (Duran ring vs CE ring)

 - Chi-square statistics or the Fisher exact test