Transcatheter Mitral and Pulmonary Valve Therapy

The use of imaging in new transcatheter interventions: an EACVI review paper

Transcatheter therapies for the treatment of valve heart diseases have expanded dramatically over the last years. The new developments and improvements in devices and techniques, along with the increasing expertise of operators, have turned the catheter-based approaches for valvular disease into an established treatment option. Various imaging techniques are used during these procedures, but echocardiography plays an essential role during patient selection, intra-procedural monitoring, and post-procedure follow-up. The echocardiographic assessment of patients undergoing transcatheter interventions places demands on echocardiographers that differ from those of the routine evaluation of patients with valve disease, and there is a need for specific expertise for those working in the cath lab. In the context of the current rapid developments and growing use of transcatheter valve therapies, this document intends to update the previous recommendations and address new advancements in imaging, particularly for those involved in any stage of the treatment of patients with valvular heart diseases.

Recent developments in percutaneous mitral valve treatment

In recent years, various percutaneous techniques have been introduced for the treatment of mitral regurgitation (MR), including direct leaflet repair, annuloplasty and left ventricular remodeling. Percutaneous mitral repair targets both primary degenerative and secondary mitral valve regurgitation and may be considered in selected high-surgical-risk patients. The assessment of mitral functional anatomy by echocardiography and computed tomography is crucial when selecting the appropriate repair strategy, according to the regurgitant valve lesion and the surrounding anatomy. The ongoing clinical use of new devices in annuloplasty and percutaneous mitral valve replacement is a promising new scenario in the treatment of MR that goes beyond the conventional surgical approach.

Contractile mitral annular forces are reduced with ischemic mitral regurgitation

OBJECTIVE

Forces acting on mitral annular devices in the setting of ischemic mitral regurgitation are currently unknown. The aim of this study was to quantify the cyclic forces that result from mitral annular contraction in a chronic ischemic mitral regurgitation ovine model and compare them with forces measured previously in healthy animals.

METHODS

A novel force transducer was implanted in the mitral annulus of 6 ovine subjects 8 weeks after an inferior left ventricle infarction that produced progressive, severe chronic ischemic mitral regurgitation. Septal-lateral and transverse forces were measured continuously for cardiac cycles reaching a peak left ventricular pressure of 90, 125, 150, 175, and 200 mm Hg. Cyclic forces and their rate of change during isovolumetric contraction were quantified and compared with those measured in healthy animals.

RESULTS

Animals with chronic ischemic mitral regurgitation exhibited a mean mitral regurgitation grade of 2.3 ± 0.5. Ischemic mitral regurgitation was observed to decrease significantly septal-lateral forces at each level of left ventricular pressure (P < .01). Transverse forces were consistently lower in the ischemic mitral regurgitation group despite not reaching statistical significance. The rate of change of these forces during isovolumetric contraction was found to increase significantly with peak left ventricular pressure (P < .005), but did not differ significantly between animal groups.

CONCLUSIONS

Mitral annular forces were measured for the first time in a chronic ischemic mitral regurgitation animal model. Our findings demonstrated an inferior left ventricular infarct to decrease significantly cyclic septal-lateral forces while modestly lowering those in the transverse. The measurement of these forces and their variation with left ventricular pressure contributes significantly to the development of mitral annular ischemic mitral regurgitation devices.

Percutaneous transcatheter mitral valve repair: a classification of the technology

Surgical treatment of mitral regurgitation (MR) has evolved from mitral valve replacement (MVR) to repair (MVR(e)), because MVR(e) produces superior long-term outcomes. In addition, MVR(e) can be achieved through minimally invasive approaches. This desire for less invasive approaches coupled with the fact that a significant proportion of patients--especially elderly persons or those with significant comorbidities or severe left ventricular (LV) dysfunction, are not referred for surgery, has driven the field of percutaneous MVR(e). Various technologies have emerged and are at different stages of investigation. A classification of percutaneous MVR(e) technologies on the basis of functional anatomy is proposed that groups the devices into those targeting the leaflets (percutaneous leaflet plication, percutaneous leaflet coaptation, percutaneous leaflet ablation), the annulus (indirect: coronary sinus approach or an asymmetrical approach; direct: true percutaneous or a hybrid approach), the chordae (percutaneous chordal implantation), or the LV (percutaneous LV remodeling). The percutaneous edge-to-edge repair technology has been shown to be noninferior to open repair in a randomized clinical trial (EVEREST II [Endovascular Valve Edge-to-Edge REpair Study]). Several other technologies employing the concepts of direct and indirect annuloplasty and LV remodeling have achieved first-in-man results. Most likely a combination of these technologies will be required for satisfactory MVR(e). However, MVR(e) is not possible for many patients, and MVR will be required. Surgical MVR is the standard of care in such patients, although percutaneous options are under development.

Mitral regurgitation secondary to anterior leaflet rupture during percutaneous balloon valvuloplasty: case report

Rheumatoid heart disease and the mitral stenosis secondary to it in the long term are still important cardiovascular problems in developing countries. Percutaneous balloon mitral valvuloplasty is a valid treatment option with low complication rates for relieving the signs and symptoms of selected patients with mitral valve stenosis. In this report, we describe subacute mitral regurgitation secondary to anterior leaflet rupture following percutaneous balloon mitral valvuloplasty and the management strategy in a 54-year-old female patient. Such a complication is rare in experienced hands in the current era.

Exercise echocardiography in the evaluation of severity of functional mitral regurgitation in patients with heart failure

We present two cases with ischemic cardiomyopathy and similar functional mitral regurgitation (fMR) at rest, who represented different outcomes following mitral valve repair. In case 1, fMR was enhanced during exercise echocardiography, and his symptoms were improved following the repair and coronary artery bypass graft (CABG). In case 2, fMR did not change during exercise, and the improvement of his symptoms was small following the operation. Exercise echocardiography evidenced variability of the dynamic changes in fMR in patients with ischemic cardiomyopathy. The variability may be related to the outcome of the mitral valve repair.