Malouf, Joseph

Structural heart disease is a rapidly evolving field, and approaches to procedural training are not standardized. We describe a novel modular approach to procedural training that considers each procedure as a series of building blocks that may be taught and assessed separately. Ten key structural heart disease building blocks can be identified, which, when combined with the cognitive skills of structural intervention and device-specific training, allow appropriate planning and implementation of structural procedures. Structural procedures require careful navigation of the aorta, left atrium, and right heart, including detailed understanding of relational anatomy. Component blocks include large bore vascular access, navigation within the left atrium, occlusion, snaring, and 3-dimensional relational anatomy. These building blocks also provide the foundation for new procedures through innovative use of the skill sets and devices to approach new clinical problems. The addition of device-specific training may be provided via proctoring and industry support. Using this approach, competency in less common procedures may be achieved and maintained. We discuss each building block in detail, approaches specific to the structural heart disease patient, the need for cross-discipline training, and empirical recommendations for training using this approach. We postulate that this new paradigm may be the preferred approach for training and assessment of structural heart disease interventional skills.

Background— Fibro-elastic deficiency (FED) and diffuse myxomatous degeneration (DMD) are phenotypes of degenerative mitral valve disease defined morphologically. Whether physiological differences in annular and valvular dynamics exist between these phenotypes remains unknown. Methods and Results— We performed triple quantitation of cardiac remodeling and of mitral regurgitation severity and of annular and valvular dimensions by real-time 3-dimensional-transesophageal-echocardiography. Forty-nine patients with degenerative mitral valve disease classified as FED (n=31) and DMD (n=18) by surgical observation showed no difference in age (65±10 versus 59±13; P =0.5), body surface area (2.0±0.2 versus 2.0±0.2 m 2 ; P =0.5), left ventricular and atrial dimensions (all P >0.55), and mitral regurgitation regurgitant orifice ( P =0.62). On average, annular dimensions were larger in DMD versus FED, but height was similar resulting in lower saddle shape. Dynamically, annular DMD versus FED display poorer contraction and saddle-shape accentuation in early systole and abnormal enlargement, particularly intercommissural, in late-systole (all P <0.05). Valvular dynamics showed stable valvular area in systole in FED versus considerable systolic increased area in DMD ( P <0.001). Prolapse height and volume increased little throughout systole in FED versus marked increase in DMD ( P <0.001). Conclusions— Our novel observations show that FED and DMD, although both labeled myxomatous, display considerable physiological phenotypic differences. In DMD, the annular increased size and profoundly abnormal dynamics demonstrate DMD-specific annular degeneration compared with the enlarged but relatively normal FED annulus. DMD does not incur more severe mitral regurgitation, despite larger prolapse and valve redundancy, underscoring potential compensatory role of tissue redundancy of DMD (or aggravating role of tissue paucity of FED) on mitral regurgitation severity.

Objectives Cleft-like indentations (CLI) are deep separations between scallops of the mitral posterior leaflet observed in myxomatous mitral valve disease (MMVD), but their diagnosis, mechanisms and implications are unknown. Using 3D transoesophageal echocardiography (3DTOC), we aimed at assessing diagnostic accuracy and defining mechanisms of CLI in patients undergoing surgery for MMVD. Methods 3DTOC of mitral valve was acquired in 49 patients with MMVD and severe regurgitation prior to valve repair. Qualitative review compared 3DTOC diagnosis of CLI with surgical inspection. Mitral, annular and leaflet dimensions were quantified with dedicated software and compared between those with and without CLI. Results Diagnosis of CLI was made by 3DTOC in 17 (35%) while none was identified by 2D and was confirmed in 15 (88%) by surgical inspection. Mechanistically, LV diameters and mitral regurgitant volume (RVol) were similar with and without CLI (p>0.49). Conversely, mitral annulus was smaller with CLI (anteroposterior diameter 42.2±7.1 vs 47.0±7.5 mm, p=0.04; circumference 133±16 vs 148±19 mm, p=0.009; area 1289±326 vs 1619±427 mm2, p=0.008). Prolapse volume tended to be smaller with CLI (1.9±1.2 vs 4.0±4.3 mL, p=0.06) involving single posterior scallop at surgery (82% vs 44%, p=0.007) with smaller 3DTOC leaflet area (1574±409 vs 2019±652 mm2, p=0.01). During valve repair, surgical closure of all surgically diagnosed CLI was required. Conclusions Posterior leaflet CLI are frequent in MMVD, are identified by 3DTOC with high accuracy and require closure during valve repair. CLI are mechanistically not related to excess annular enlargement or excess prolapse. Conversely, CLI occur in the context of single scallop prolapse with tissue paucity causing excess separation of scallops. These 3DTOC data enhance diagnostic and mechanistic comprehension of the diversity of MMVD phenotypical presentation.