Percutaneous Mitral Valve Repair With the Edge-to-Edge Technique

Quantitative assessment of severity of mitral regurgitation by serial echocardiography in a multicenter clinical trial of percutaneous mitral valve repair

The aims of the echocardiographic substudy of this multicenter trial were to evaluate the use of quantitative assessment of mitral regurgitation (MR) severity using serial echocardiography and to assess the efficacy of percutaneous mitral valve repair. Previous surgical repair studies did not use quantitative echocardiographic methods. Results of a percutaneous mitral valve repair clip device in a core echocardiographic laboratory were evaluated. Published parameters for quantifying MR were used in a systematic protocol to qualify patients for study entry and evaluate treatment efficacy at discharge and 6 months after clip repair. Baseline results were presented for 55 patients, and follow-up results, for 49. Ninety-eight percent of required echocardiographic studies were submitted to the core laboratory, and >85% of required measurements were possible. At baseline, mean regurgitant volume was 54.8 +/- 24 ml, regurgitant fraction was 46.9 +/-16.2%, effective regurgitant orifice area was 0.71 +/- 0.40 cm(2), and vena contracta width was 0.66 +/- 0.20 cm. Based on a severity scale of 1 to 4, mean color flow grade was 3.4 +/- 0.7, and mean pulmonary vein flow was 2.8 +/- 1.2. In patients with a clip at 6 months, all measurements of MR severity were significantly decreased versus baseline, with mean regurgitant volume decreased from 50.3 to 27.5 ml (change -22.8 ml; p <0.0001), regurgitant fraction from 44.6% to 28.9% (change -15.7%; p <0.0001), color flow grade from an average of 3.4 to 1.8 (change -1.6; p <0.0001), and pulmonary vein flow from 2.8 to 1.8 (change -1.0; p <0.0018). In conclusion, quantitative assessment of MR is feasible in a multicenter trial, and percutaneous mitral repair with the MitraClip produces a sustained decrease in MR severity to moderate or less for > or =6 months.

The frequency, impact, and management of mitral regurgitation in patients with heart failure

Management of severe chronic mitral regurgitation (MR) in severe heart failure is challenging. There are controversies over the efficacy of surgical correction of MR in the presence of severely depressed left ventricular (LV) function. The etiology of MR plays an important role in clinical decision making. In organic MR, surgical correction should be performed even if patients have an LV ejection fraction of less than or equal to 30%. In functional MR, treatment of myocardial damage should be considered as the priority. The long-term mortality benefit of surgical correction of functional MR associated with severe LV dysfunction caused by cardiomyopathy (ischemic or dilated) likely depends on whether myocardial dysfunction can be reversed or improved by treatments (eg, coronary artery revascularization, pharmacologic treatment). Preoperative examination of viable myocardium (ischemic and hibernating myocardium) helps to identify a surgical candidate with ischemic MR associated with ischemic cardiomyopathy. The role of device treatment of MR in heart failure needs further investigation with outcome data.

Percutaneous Mitral Valve Repair

Surgical mitral valve repair is the procedure of choice to treat mitral regurgitation of all etiologies. Whereas annuloplasty is the cornerstone of mitral valve repair, a variety of other surgical techniques are utilized to correct dysfunction of the leaflets and subvalvular apparatus; in most cases, surgical repair entails application of multiple repair techniques in each patient. Preclinical studies and early human experience have demonstrated that some of these surgical repair techniques can be performed using percutaneous approaches. Specifically, there has been great progress in the development of novel technology to facilitate percutaneous annuloplasty and percutaneous edge-to-edge repair. The objectives of this report were to (1) discuss the surgical foundations for these percutaneous approaches; (2) review device design and experimental and clinical results of percutaneous valve repair; and (3) address future directions, including the key challenges of patient selection and clinical trial design.

Percutaneous valve interventions: where we are and where we are headed

Boundaries between the specialties of cardiology and cardiovascular surgery are becoming less distinct, as cardiologists and cardiac surgeons alike strive to decrease invasiveness of procedures and improve patient results. For surgeons, new tools and techniques have allowed innovative, minimally invasive techniques to be performed successfully with smaller incisions and faster recovery. With the introduction of novel catheter technology, aortic valve prostheses can be placed percutaneously or, more recently, transapically without cardiopulmonary bypass. Furthermore, the field of percutaneous mitral valve repair is rapidly expanding with multiple novel off-pump percutaneous devices designed to reduce or eliminate mitral regurgitation, including devices that perform edge-to-edge leaflet repair and percutaneous mitral annuloplasty. The explosive growth of new ideas and new procedures to decrease invasiveness of valve procedures will continue to evolve over the next 5 years, and surgeons must remain nimble to become part of this process.