The Coapsys device comprises a flexible PTFE suture cord connecting two epicardial pads (Figs. 15.2 and 15.3). It is placed under epicardial echocardiographic guidance without the need for cardiopulmonary bypass (CPB). A suction cup stabilized C-clamp with anterior and posterior locators is positioned externally on the LV. The posterior locator is positioned below the posterior MV leaflet and centrally between the two PMs (Fig. 15.4). The anterior locator is positioned on the right ventricular side of the left anterior descending coronary artery. The anterior and posterior locator positions are confirmed with epicardial echocardiography using short and long axis views, respectively (Fig. 15.5). A jig guides a needle through the LV (perpendicular to the short axis of the LV) from one locator to the other. After the needle is withdrawn, a suture chord is left passing below the mitral leaflets, between the PMs. Epicardial pads are placed on the end of this chord with the two heads of the posterior pad pressing directly behind the posterior annulus and at the level of the subvalvular apparatus. The anterior pad (single headed) contacts the cresenteric portion of the right ventricle, overlying the LV (Fig. 15.6). The device is initially placed without tension and its placement is confirmed by transesophageal echocardiography (TEE). The suture chord length is then progressively shortened to a maximum of 35 % of its baseline length, drawing the epicardial pads closer together. This reduces the anterior-posterior dimension of the MV and is typically sufficient to eliminate the mitral insufficiency [4].

The Coapsys device was initially tested in multiple experimental studies using a canine model for dilated cardiomyopathy (DCM), achieved through rapid ventricular pacing resulting in FMR [5–8]. In order to evaluate mitral annular dimensions and pressure volume relationships, Fukamachi and colleagues placed Coapsys in seven adult mongrel dogs that were asynchronously rapid ventricular paced for an average of 31 days. On the day of device placement the heart rate was reduced, putting the heart into normal sinus rhythm. The Coapsys device was placed and sized to reduce the MR on echocardiography. The rapid ventricular pacing was restarted 3 days postoperatively and maintained for 8 weeks until the dogs were sacrificed. The experimenters found that the mean MR grade was decreased from 2.5 at baseline to 0.8 at 8 weeks after Coapsys placement. Both the mitral annular and LV septo-lateral dimensions decreased, and the end systolic and end diastolic pressure-volume relations (ESPVR and EDPVR) were shifted left [7]. In a second animal study, the authors performed a similar experiment but additionally cut the Coapsys cord at the end of the study to directly evaluate the effect Coapsys had on MR. After cutting the cord, the previously improved MR parameters returned to their CHF baselines. At necropsy, the authors demonstrated that Coapsys caused no injuries to the papillary muscles, MV apparatus, or coronary arteries and veins, and no tissue erosion, thrombosis of subvalvular chords, or end organ infarction or emboli [6]. In a third animal study the Coapsys device was inserted and tightened in 5 % increments up to 40 % of baseline. The authors found that MR was maximally reduced when Coapsys was tightened to 30 %, resulting in a reduced septo-lateral dimension at the mitral annulus and subvalvular LV [5]. Together these animal studies demonstrated the efficacy and safety of Coapsys device placement in reducing MR in a DCM/FMR animal model.

The initial human clinical trial of the Coapsys device was performed at Escorts Hospital in New Delhi, India. Patients undergoing coronary artery bypass grafting (CABG) with ischemic FMR greater than grade 2, were included in this study. Intra-operatively, patients with post-CABG MR greater than grade 2 received the Coapsys device. The baseline MR grade was 2.9. Post-Coapsys placement the MR grade was 1.1 at discharge and at 12 months postoperatively. NYHA functional status improved from 2.5 at baseline to 1.2 at 12 months postoperatively, and there were no deaths or device failures [9].

Following this initial trial, the FDA permitted the sponsor to perform a randomized investigational device trial in the United States comparing surgical MV annuloplasty to Coapsys device placement in patients with moderate to severe MR undergoing CABG. The Randomized Evaluation of a Surgical Treatment for Off-Pump Repair of the Mitral Valve (RESTOR-MV) was a multicenter, investigational, randomized study with predetermined efficacy and safety end points that compared CABG plus Coapsys placement to CABG plus standard MVr [10].

Inclusion criteria included the need for revascularization and the presence of moderate or worse MR; exclusion criteria included EF <25 % and any structural leaflet abnormality. After patient consent, patients were allocated to one of two arms by surgeon discretion—either the CABG plus MVr arm or the CABG alone arm. In Arm 1 (CABG plus MVr), patients were randomized 1:1 to undergo CABG plus MV annuloplasty or CABG plus Coapsys. In Arm 2, CABG, patients were randomized 1:1 to undergo CABG alone or CABG plus Coapsys. Of 165 randomized patients 149 were placed in the CABG + MVr arm and 16 into the CABG alone arm. In Arm 1, 75 patients underwent CABG plus MVr and 74 underwent CABG plus Coapsys. In Arm 2, 16 patients undergoing CABG alone, 8 were randomized to CABG plus Coapsys and 8 to CABG alone [10].