Transcatheter mitral valve repair options expand
medwireNews: Researchers have successfully used a new transcatheter mitral valve repair device in 11 patients in a first-in-human trial.
The TSD-5 device (Harpoon Medical Inc, Baltimore, Maryland, USA) is a shafted device with a 3 mm diameter designed to attach expanded polytetrafluoroethylene (ePTFE) artificial cords to the prolapsed mitral valve leaflet in a beating heart.
The device is inserted through the epicardium 3 to 4 cm basal to the apex and attaches the ePTFE cords to the posterior leaflet with a double-helix knot on the atrial side. Cord length is optimised using transoesophageal echocardiography and the cords are secured with another knot on the surface of the epicardium, at the insertion point.
As reported in Circulation, James Gammie (University of Maryland School of Medicine, Baltimore, USA) and co-researchers tested the device in 11 patients (average age 65 years, 91% men) with severe degenerative mitral regurgitation (MR) due to isolated posterior leaflet prolapse.
The procedure took an average of 108 minutes and was successful in all 11 patients, Gammie and team report. They implanted an average of 3.6 ePTFE cords per patient, which resulted in MR decreasing to none/trace in eight patients and mild in three patients.
One patient had recurrent severe MR identified 60 days later, upon the recurrence of dyspnoea, and underwent conventional valve surgery at postoperative day 72. During surgery, it emerged that all three ePTFE cords remained attached to the posterior leaflet, but one of the knots at the epicardial surface had become untied.
At 30 days postoperatively, four of the other patients still had no or trace MR, five had mild MR and one had developed moderate MR. The patients had no sign of mitral stenosis, and there was evidence of early ventricular remodelling, with end-diastolic dimension decreasing by 11% on average and end-diastolic volumes by 18%, and of favourable atrial remodelling.
In a linked editorial, Michael Mack and Robert Smith (Baylor Scott & White Health, Plano, Texas, USA) assess the advantages and disadvantages of surgery versus transcatheter mitral valve repair, and compare current progress with experience of transcatheter aortic valve replacement.
They say that, for transcatheter mitral valve repair, “[t]he technical challenges are greater, and the path to clear demonstration of clinical benefit and widespread clinical adoption will be longer and more challenging.”
Since primary MR is a heterogeneous disease, a range of techniques will be required, the editorialists observe. “It will not be a one-size-fits-all answer.”
And they add: “The challenges of treating secondary MR are significantly greater, and valve replacement strategies are likely to predominate.”
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