New devices for treating severe heart failure Mar 13, 2000New devices for the treatment of severe heart failureAnaheim, CA- The first data on two new devices for use in patients with severe heart failure were reported on March 13, 2000 at theAmerican College of Cardiologymeeting. Both of the devices are implanted into the failing heart, with the aim of changing its shape and improving its functioning. Preliminary data from safety clinical trials on the Acorn®device suggest that it has a beneficial effect, while preclinical results with the MyosplintTMdevice have already led to acute testing in patients, with a chronic use clinical trial now planned.ACORN DEVICE "REPRESENTS MAJOR PROGRESS"The Acorn device, a passive constricting textile device developed byAcorn Cardiovascular, Inc, St Paul, MN, has recently completed initial safety clinical trials in Germany. Data from 26 patients were presented byDr Franz Kleber(Unfallkrankenhaus, Berlin, Germany). These patients had severe Class III heart failure or worse, and the initial 16 had the Acorn device implanted while they underwent valvular surgery, mainly for mitral insufficiency. Once the surgical team had some experience with implanting the device - the knitted polyester device is placed over the ventricles and sewn onto the AV groove - they offered it as an option to patients not scheduled for other surgery, and 10 further patients only had the device implanted. At present, the procedure is carried out with cardiopulmonary bypass, but it may not be necessary in the future, Kleber commented. After 3 months, there was a "considerable reduction" in the end diastolic volume (from 169+20 ml/m2to 145+29ml/m2), which he described as "the hallmark of heart disease." There was also a reduction in mitral insufficiency, even in those patients who didn't have valvular surgery, he noted.Dr Wolfgang Konetz(Charite Hospital, Berlin, Germany) presented further clinical data on 25 patients, of whom 12 had concomitant valvular surgery. After 3 months, there was a reduction in the left ventricular end diastolic dimension from 77.5 (62-82) at baseline to 74.5 (54-86) mm. There was also a reduction in the LV end systolic dimension, and in the mitral regurgitation grade, while the LV ejection fraction increased. There were no device-related adverse effect or deaths. The product appears safe, and there are "positive trends towards patient benefit," Konetz concluded."WE CAN PROBABLY STOP THE PROGRESSION OF HEART FAILURE"Although these were primarily safety studies, the results suggest that the procedure has beneficial effects, although it is too early yet to comment on efficacy, Kleber commented in response to questions from the audience. In an interview withheartwire, he said: "I think this device represents major progress in the field of heart failure." The device has a constrictive effect, but it does not squeeze the heart, he commented - its main effect is to avoid intermittent overstretching for example during exercise, and this leads to a positive reshaping and a smaller size. He noted that this is the first treatment modality to address the issue of intrinsic afterload, and commented: "If we can modulate intrinsic afterload, we can probably stop the progression of heart failure."Kleber also recalled how he had first had the idea of enclosing the failing heart in a mesh device back in 1993, but had never gone beyond concept. Acorn Cardiovascular developed the device quite independently, but when Kleber received the phone call inviting him to carry out the clinical trials, it was like "all my Christmases coming at once." The company had made the "heart mesh" that he had envisaged, and he was only too eager to try it out. Acorn made contact with the Berlin clinicians after hearing about Konetz's experience with the "Batista" operation, an experimental operation in which the surgeon attempts to remove part of the muscle in order to reduce heart size.MYOSPLINT DEVICE IN PRECLINICAL TRIALSThe Myosplint device, developed byMyocorin Minneapolis, MN, works on a different principle. It consists of a long thin thread "tension member," with a fixed pad at one end and an adjustable pad at the other, explainedDr Patrick McCarthy(Surgical Director, Kaufman Center for Heart Failure, Cleveland Clinic Foundation, OH). It is threaded through the left ventricle with a needle, and then pulled taut, with the moveable pad adjusted until there is a 20% reduction in wall stress. This changes the shape of the left ventricle from circular to bilobular, and this shape change improves the heart's functioning.In preclinical studies carried out in a canine model of heart failure, the device significantly reduced end diastolic volume and produced a "highly significant" increase in ejection volume, from 20% in controls (n=4) to 30% in the device-treated group (n=5), McCarthy reported. The device appears to be safe, he commented - there was no sign of thrombus after 4 weeks, and chronic preclinical studies conducted at the Mayo Clinic saw a complete endotheliasation of the tension member. "The device is easily applied to the beating heart, and is worth investigating further," McCarthy concluded.In an interview withheartwire, McCarthy said that he has now tried the Myosplint device in three patients awaiting a heart transplant. While the new heart is being prepared, the device has been implanted and functioning assessed for 30 minutes before the transplant operation begins. So far the results are similar to those seen in animals, and a clinical trial to assess how the device performs chronically is now planned. The trial will be carried out in Germany, and is scheduled to involve about 30 patients with Class II/III heart failure.Zosia ChusteckaRelated linktheheart.org commentary/ Dec 13, 1999 /Surgical adjuncts in the treatment of heart failureTue, 14 Mar 2000 02:24:57