One characteristic of functional MR is the presence of “normal” leaflet structure in the setting of ventricular remodeling which distorts the subvalvular apparatus and impairs valve function. A novel approach to treating this FMR is offered by the Coapsys device (Myocor, Inc., Maple Grove, MI), a ventricular shape change device that can be placed without the need for cardiopulmonary bypass to reduce FMR. This device consists of two pads which are connected by a transventricular “chordal” suture. After echocardiographically assisted placement across the left ventricle, the device is tightened to compress the mitral annulus, thereby reducing FMR and positively reshaping the ventricle [35]. An FDA-monitored investigational device trial was conducted in patients requiring CABG who had severe MR or symptomatic moderate MR, ejection fractions >=25 %, and LVEDD  <  =7.0 cm. The hypotheses tested were that investigative “off-pump” treatment would have non-inferior efficacy (as measured by MR degree) and superior safety efficacy as compared to standard mitral repair [36]. The trial was terminated prematurely when the recent financial collapse resulted in the bankruptcy of the trial sponsor (Myocor Inc.).

Recruitment had accrued 165 patients, the prespecified value for the “first-look” data ­analysis. The Coapsys device was associated with greater long-term positive ventricular reshaping, with the LVEDD decreasing from 6.0  ±  0.8 to 5.4  ±  0.8 cm as compared to 5.9  ±  0.7 to 5.6  ±  0.9 cm for the control MV repair (effect of time p  <  0.001, repeated measures analysis of variance [ANOVA]; effect of treatment p  =  0.02). However, the MR treatment efficacy was not as effective with the Coapsys treatment: the standard mitral repair technique reduced MR (0  =  none, 1  =  mild, 2  =  moderate, 3  =  moderate-severe, 4  =  severe scale) from 2.54  ±  0.80 to 0.35  ±  0.63 at 24 months, while Coapsys reduced MR from 2.40  ±  0.87 to 1.24  ±  0.97 (both effect of time and treatment p  =  0.0001, repeated measures ANOVA). What was totally unanticipated was that the trial discerned a significant survival benefit to the Coapsys treatment; at 24 months, there was nearly half the incidence of death with the Coapsys device as compared to standard mitral repair (Fig. 4.1). Twenty-four-month survival from all cause death was 89 % in the Coapsys randomized group as compared to 78 % in the standard treatment group (adjusted log-rank 4.30; p  =  0.038; intent-to-treat analysis); a more powerful benefit to the Coapsys treatment was noted in the as-treated analysis (p  =  0.020).

These findings are very provocative: patients with FIMR requiring revascularization treated with ventricular reshaping rather than standard mitral repair surgery had improved survival and significant reduction of major adverse outcomes. This unique dataset should guide further research in this area towards “ventricular solutions.”

Currently two topical clinical trials regarding the outcomes of ischemic mitral regurgitation are being conducted by the National Heart, Lung, and Blood Institute (NHLBI)-sponsored Cardiothoracic Surgical Trials Network. The first trial is entitled “Evaluation of Outcomes Following Mitral Valve Repair or Replacement in Severe Chronic Ischemic Mitral Regurgitation.” In this study, patients with severe FIMR will be randomized to either mitral repair or replacement; concomitant CABG will be performed if indicated. Pre- and postoperative evaluation will include cardiopulmonary exercise evaluation. The patients will be followed for 24 months. Interestingly, no restrictions are being applied as to the mitral valve repair technique employed by an individual surgeon.

The second trial is entitled “Surgical Interventions for Moderate Ischemic Mitral Regurgitation.” The purpose of this trial is to determine whether repairing moderate mitral insufficiency at the time of planned CABG will have beneficial effects. Again, cardiopulmonary exercise testing, neurocognitive tests, and quality of life surveys will be conducted over a 2-year period. Unfortunately, patient recruitment has been an issue for both trials. It has been speculated that there is a lack of clinical equipoise when treating “stentable” coronary artery disease in the presence of moderate MR which has limited patient referral. The NHLBI has announced a request for additional investigative sites to correct this issue.