Masao Daimon

Tricuspid Valve Tethering Predicts Residual Tricuspid Regurgitation After Tricuspid Annuloplasty

Background—Tricuspid valve (TV) annuloplasty is recommended for functional tricuspid regurgitation (TR), which is caused by TV annulus dilatation and tethering of the leaflets. However, the impact of TV deformations on the outcome of TV annuloplasty remains unknown. The goal of this study was to investigate the relationship between preoperative TV deformation and residual TR after TV annuloplasty. Methods and Results—Two hundred sixteen patients with functional TR had 2D echocardiography before and after TV annuloplasty. Right ventricular fractional area change and left ventricular ejection fraction were determined with the apical views. Minimal TV annulus diameter was determined by frame-by-frame analysis. The distance of TV tethering was measured from the annulus plane to the coaptation point and tethering area by tracing the leaflets from the annulus plane. TR severity was determined by the ratio of the maximal jet area to the corresponding right atrial area. The severity of residual TR was associated with age, right and left ventricular dysfunction, tethering distance and area, and severity of preoperative TR (all P<0.05). TV annular dimension was not associated with outcome of TV annuloplasty. Multivariate analysis revealed that age, tethering distance, and severity of preoperative TR (all P<0.001) were independent parameters predicting residual TR. The sensitivity and specificity in predicting residual TR after surgery were 86% and 80% for tethering distances >0.76 cm and 82% and 84% for tethering areas >1.63 cm2, respectively. Conclusions—Severe TV tethering predicted residual TR after TV annuloplasty, whereas preoperative TV annular dimension was not associated with outcome of TV annuloplasty.

Three-Dimensional Geometry of the Tricuspid Annulus in Healthy Subjects and in Patients With Functional Tricuspid Regurgitation A Real-Time, 3-Dimensional Echocardiographic Study

Background— Most rings currently used for tricuspid valve annuloplasty are formed in a single plane, whereas the actual tricuspid annulus (TA) may have a nonplanar or 3-dimensional (3D) structure. The purpose of this study was therefore to investigate the 3D geometry of the TA in healthy subjects and in patients with functional tricuspid regurgitation (TR). Methods and Results— This study consisted of 15 healthy subjects and 16 patients with functional TR who had real-time 3D echocardiography. With our customized software, 8 points along the TA were determined with the rotated plane around the axis at 45°intervals. The TA was traced during a cardiac cycle. The distance between diagonals connecting 2 points was measured. The height was defined as the distance from the plane determined by least-squares regression analysis at all 8 points. Both the maximum (7.5±2.1 versus 5.6±1.0 cm2/m2) and minimum (5.7±1.3 versus 3.9±0.8 cm2/m2) TA areas in patients with TR were larger than those in healthy subjects (both P<0.01). Healthy subjects had a nonplanar-shaped TA with homogeneous contraction. The posteroseptal portion was the lowest toward the apex from the right atrium, and the anteroseptal portion was the highest. In patients with functional TR, the TA was dilated in the septal to lateral direction, resulting in a more circular shape than in healthy subjects. A similar 3D pattern was observed in patients with TR, but it was more planar than that in healthy subjects. Conclusions— Real-time 3D echocardiography showed a complicated 3D structure of the TA, which appeared to be different from the “saddle-shaped” mitral annulus, suggesting an annuloplasty for TR different from that for mitral regurgitation.

Determinants of recurrent or residual functional tricuspid regurgitation after tricuspid annuloplasty

Background— The durability of tricuspid valve (TV) repair by annuloplasty is limited. Identification of mechanisms of recurrent or residual tricuspid regurgitation (TR) after annuloplasty is necessary to improve results of TV repair. The purpose of this study was to investigate echocardiographic determinants of mid-term outcome after TV annuloplasty. Methods and Results— This study consisted of 39 patients with functional TR who had echocardiography preoperatively, early postoperatively (5±2 days), and >1 year (20±6 months) after TV annuloplasty. Detailed echocardiographic measurements were performed, including TR severity, TV annular dimension, TV leaflet displacement, left ventricular (LV) function, and right ventricular (RV) function and pressures. Preoperative leaflet tethering height and area predicted early and mid-term outcome of annuloplasty. Early postoperative LV ejection fraction and TR severity influenced degree of TR >1 year after surgery. In addition, increased RV pressure was related to worse TR during late follow-up. Conclusions— Although TV tethering is an important determinant of recurrent or residual TR, LV and RV function and pressures impact repair durability. These factors identify patients at risk for repair failure; such individuals require development of additional surgical strategies to improve results of tricuspid valve repair and close surveillance after surgery.

Mitral Valve Repair With Carpentier-McCarthy-Adams IMR ETlogix Annuloplasty Ring for Ischemic Mitral Regurgitation Early Echocardiographic Results From a Multi-Center Study

Background— Ischemic mitral regurgitation (IMR) is associated with asymmetric changes in annular and ventricular geometry. Surgical repair with standard symmetric annuloplasty rings results in a high incidence of residual or recurrent mitral regurgitation (MR). The Carpentier-McCarthy-Adams (CMA) IMR ETlogix annuloplasty ring is the first remodeling ring specifically designed to treat asymmetric leaflet tethering and annular dilatation. We used quantitative 2-dimensional echo to examine early results of mitral valve (MV) repair with the CMA IMR ETlogix annuloplasty ring in patients with IMR. Methods and Results— Fifty-nine patients (aged 68±12 years) with grade ≥2+ IMR (graded on a scale of 0 to 4+) underwent MV repair with the CMA IMR ETlogix annuloplasty ring. We assessed the mitral annular diameter (MAD), tethering area (TA), and tenting height (TH) of the MV in 4-chamber, 2-chamber, and long axis views at mid-systole before and 3 to 10 days after surgery. After surgery, 57 of 59 (97%) patients had grade 0 or 1+ MR, whereas 2 patients had 2+ MR. MV repair with the CMA IMR ETlogix ring significantly reduced MAD, TA, and TH (P<0.001, for all 3 echo views), particularly in the long axis and 4-chamber views. Conclusion— Surgical repair of IMR with the novel asymmetric CMA IMR ETlogix annuloplasty ring provided excellent early results with effective reduction of MR, MAD, and leaflet tethering. This novel etiology-specific strategy may result in improved outcomes in IMR patients.

Local dysfunction and asymmetrical deformation of mitral annular geometry in ischemic mitral regurgitation: A novel computerized 3D echocardiographic analysis

Objective: Most studies of the pathogenesis of functional mitral regurgitation (MR) have focused on alterations in ventricular function and geometry. We used a novel 3D echocardiographic method to assess abnormalities in mitral annular (MA) geometry and motion in patients with ischemic MR (IMR) and compared these data to those obtained from normal subjects and from patients with MR caused by dilated cardiomyopathy (DMR). Methods: Real time 3D echo was performed in 12 normal subjects, 25 with IMR, and 14 with DMR. Eight points along the saddle‐shaped MA were identified using our software at systole and diastole. From these eight points, four annular diameters at each cardiac phase were determined. Annular motion was assessed by measuring local displacement (LD) of a given point between systole and diastole. Results: Annular motion was different between groups: IMR had smaller LD in posterior MA segments than did normals (2.6 ± 1.1 vs 4.8 ± 1.9 mm, P < 0.01), while DMR had globally reduced LD. In IMR systolic MA dilatation was striking in the anterior–posterior (diameter; IMR vs controls, 28.3 ± 3.5 vs 22.5 ± 2.2 mm, P< 0.05) and anterolateral–posteromedial (31.7 ± 3.5 vs 25.1 ± 2.2 mm, P < 0.05) directions; in IMR, systolic MA diameters in these two directions correlated with MR severity (P = 0.02) . MA dilatation occurred globally in DMR. Conclusion: This novel 3D echo method demonstrated that MA motion and dilatation were asymmetric in IMR and symmetric in DMR. These differences in MA geometry and motion may aid in the development of distinct new therapies for IMR and DMR.

Dynamic Change of Mitral Annular Geometry and Motion in Ischemic Mitral Regurgitation Assessed by a Computerized 3D Echo Method

Objective: In patients with ischemic mitral regurgitation (IMR), we assessed dynamic changes in mitral annular geometry and motion during the cardiac cycle, and examined their association with the severity of IMR, using our computerized three‐dimensional (3D) echo method. Methods: Real‐time 3D echo was performed in 12 normal controls and 25 patients with IMR. The saddle‐shaped annulus was reconstructed in every 3D volume/frame during a cardiac cycle. For each 3D volume/frame, we assessed the mitral annular area (MAA) and the annular contraction that was expressed as the percentage of the largest MAA accounted for by the change in MAA from largest to smallest calculated value. Results: In IMR patients, the minimum MAA occurred in late‐systole, while it occurred in early‐systole in the controls. IMR patients had a larger minimum MAA (6.7 ± 1.3 vs. 3.6 ± 0.8 cm2, P < 0.001) and reduced annular contraction (23.0 ± 6.5 vs. 42.6 ± 7.0%, P < 0.001) when compared to controls. Both minimum MAA and annular contraction had significant correlations with IMR severity (r = 0.67 and r = 0.78, P < 0.001 for both). Conclusion: The contraction of the dilated mitral annulus occurred in late‐systole in patients with IMR. The alterations of annular geometry and motion may be associated with the development of IMR. (Echocardiography 2010;27:1069‐1077)

An experimental rabbit model for off-pump left ventricular reconstruction following left ventricular aneurysm.

BACKGROUNDnCardiac electromechanical remodeling following left ventricular reconstruction (LVR) surgery is not fully understood. Further development of an animal model will facilitate investigations in this area. In the present study, we aimed to establish a novel LVR procedure without the use of cardiopulmonary bypass in a rabbit left ventricular (LV) aneurysm model.nnnMETHODSnLV aneurysm was created in 6 rabbits by ligation of the distal left coronary artery. More than a month later, LVR aneurysm surgery was performed off-pump using a purse-string suture around the aneurysm. Cardiac dimensions and function were evaluated using echocardiographic techniques perioperatively and 4 weeks after LVR surgery. Six structurally normal hearts were used as controls.nnnRESULTSnLVR surgery was successfully performed in all 6 rabbits. Both LV end-diastolic volume (LVEDV, 4.6 +/- 0.9 to 3.3 +/- 0.6 mL; P < .01) and LV end-systolic volume (LVESV, 2.5 +/- 0.6 to 1.5 +/- 0.2 mL, P < .01) were decreased immediately postsurgery versus presurgery, and LV ejection fraction (LVEF) was increased (44.5 +/- 5.3 to 55.6 +/- 4.8%, P < .001). For comparison, in normal rabbits (n = 6), LVEDV, LVESV and LVEF were 3.1 +/- 0.7 mL, 1.2 +/- 0.5 mL, and 64.5 +/- 8.8%, respectively. During follow-up, one rabbit died 3 weeks after surgery from an unknown cause. In the remaining 5 animals, improvements of LVEDV (3.7+/- 0.4 mL, P < .05), LVESV (1.7 +/- 0. 3 mL, P < .01), and LVEF (53.1 +/- 2.8%, P < .01) were maintained versus presurgery values for more than 4 weeks after LVR.nnnCONCLUSIONSnOff-pump LVR of rabbit LV aneurysm is an effective and less invasive surgery that resulted in sustained improvement in cardiac function with no gross intraoperative or postoperative mortality. This may be a useful model for investigations of electromechanical remodeling following LVR.

Acute Reduction of Functional Mitral Regurgitation in Canine Model Using an Epicardial Device

PURPOSEnThis study evaluated the short-term feasibility of a novel epicardial device that treats functional mitral regurgitation by simultaneously changing the mitral and the left ventricular geometry.nnnDESCRIPTIONnWe implanted a prototype device that consists of 2 tissue anchors, a deflector, and a flexible tightening chord in 7 mongrel dogs with heart failure and functional mitral regurgitation induced by rapid ventricular pacing. Hemodynamic and echocardiographic data were obtained before and after device implantation.nnnEVALUATIONnThe device acutely reduced the mitral regurgitation grade from 3.2 +/- 0.3 to 0.9 +/- 0.5 (p < 0.001). Left ventricular end-diastolic volume (79.6 +/- 23.6 to 61.2 +/- 16.9 mL; p = 0.004) and end-systolic volume (63.1 +/- 17.3 to 49.2 +/- 12.3 mL; p = 0.006) decreased substantially. End-systolic elastance significantly increased from 1.9 +/- 1.0 to 2.6 +/- 1.4 mm Hg/mL (p = 0.02). Device implantation did not alter coronary perfusion.nnnCONCLUSIONSnThe epicardial device acutely reduced functional mitral regurgitation and improved left ventricular geometry. Further studies are required to demonstrate the long-term safety and efficacy of this concept.