FMR is a well recognised consequence of the left ventricular remodelling that commonly occurs in heart failure patients. “When hearts dilate, it’s as if the door frame holding the mitral valve leaflets becomes too big with the result that the leaflets don’t close adequately,” explained Dr David Reuter, from Seattle Children’s Hospital, USA, who presented the study. FMR affects around 90% of patients with heart failure and can increase mortality, with studies suggesting that mild FMR is associated with 10% annual mortality, moderate with 20% and severe with 30 to 40%.
While medical therapies (ACE inhibitors, ARBS, beta blockers and diuretics) offer the standard of care for heart failure patients with FMR, surgical repair in patients undergoing CABG procedures has demonstrated clinical benefits.
“When surgery worked, it provided proof that a mechanical solution could improve symptoms for these patients, but the risks of surgery outside CABG were generally considered too high for this fragile group,” said Reuter.
The CARILLION® Mitral Contour System, developed by Cardiac Dimensions Inc (Kirkland, Washington), offers a percutaneous approach that can optimise the risk: benefit profile. The
device has been designed to be positioned in the coronary sinus (under fluoroscopic guidance), taking advantage of the heart’s anatomy where the coronary sinus runs parallel to the entire length of the posterior leaflet of the mitral valve. The device, which is made of nitinol, consists of two anchors connected by a shaping ribbon conforming to the natural contours of the coronary sinus. The implant is anchored in two places, resulting in a “reshaping” of the annulus around the mitral valve, with the resultant effect that FMR is reduced. The average time taken for the procedure, which is performed in the catheter lab, is just 38 minutes.
In the Transcatheter Implantation of the CARILLON Mitral Annuloplasty (TITAN) study, which took place in six centres in Germany, Poland and France, 53 patients with FMR and systolic heart failure underwent percutaneous mitral annuloplasty with the CARILLION system. To be eligible, patients had to have left ventricular dilation, at least moderate FMR and walk between 150 and 450 metres in six minutes. Altogether, 36 patients had the device left in position and 17 had it recaptured due to reductions in coronary blood flow or insufficient reduction in FMR. The analysis presented at Heart Failure 2012 compared the 12 and 24 month data for patients fitted with the device to their own baseline data.
The results showed that the 30-day major adverse event (MAE) rate (defined as a composite of death, MI, cardiac perforation, device embolisation and surgery for device failure) was 1.9%.
Results show that for patients fitted with the device, mitral regurgitation was reduced from 35 ± 12ml at baseline to 17 ± 12ml through 12 months (P=0.001). Furthermore, the left ventricular end systolic volume was 152 ± 57ml at baseline versus 121 ± 43ml through 12 months (P=0.015).
The average six minute walk test was 303 ± 74 metres at baseline, 406 ± 180 metres at 12 months, and 450 metres ± 99 metres at 24 months (p=0.005). The NYHA Class improved from 3.1 ± 0.23 at baseline to 2.1 ± 0.64 at 12 months and remained at 2.1 ± 0.74 through 24 months (p<0.001).
“These data demonstrate the durability of the effect at both 12 and 24 months, and hold out the hope that there may be a subset of patients where, if you intervene at the right time, you could modify the course of the disease,” said Reuter.