Louis: here's a news item on VADs. Given they are talking about the larger clunky units that perforate the abdomen, the HeartSaver should be well positioned when the results of further trials come out...
Left Ventricular Assist Devices May Become Permanent Alternatives To
Transplant
WESTPORT, May 20 (Reuters) - Left ventricular assist devices (LVAD) may turn out to be viable long-term alternatives to heart transplantation in patients with severe heart failure, according to an article published in the May 20 issue of Circulation.
Researchers at Sharp Memorial Hospital in San Diego, California, studied exercise and functional capacity in 10 patients in whom the devices had been implanted only as a bridge to transplantation. The San Diego trial was designed to pave the way for the multicenter Experience with Ventricular Assist Device with Exercise (EVADE) trial, in which results of treadmill tests in patients with the assist devices will be compared with results in the same patients after heart transplant.
In an interview with Reuters Health, lead author Dr. Brian E. Jaski explained that "[t]here's been a great deal of interest in use of these left ventricular assist devices as alternatives to heart transplants, but, if they are to be used this way, we have to know
that patients can be functional....There have been anecdotes about exercise in patients with these devices implanted, but, until now, there have been no physiologic studies to assess patients' capacity to do activities of daily living. We wanted to determine what their exercise capacity was, and what their physiology was during exercise."
Dr. Jaski reports that, by an average of 46 days after device placement, the study subjects had "...achieved maximum consumption of oxygen during exercise tests of the same order of magnitude that patients achieve at the same period post-heart transplantation." In addition, he said, their pulmonary capillary wedge pressures were
similar to those of heart transplant recipients.
"What we've demonstrated objectively is that these people have been returned to a state that's similar to Class II compensated heart failure or to patients' [functional capacity] at a similar interval following heart transplantation," Dr. Jaski said. He added that heart recipients' functional capacity generally improves over the first year
posttransplant, but that because these 10 subjects eventually underwent transplantation, it was not possible to follow them long enough to determine whether or not their exercise capacity with the assist devices in place would continue to improve in a similar
manner.
"A direct comparison of [left ventricular assist device] implantation with medical therapy for patients with advanced heart failure will have to await the results of other ongoing randomized trials comparing these two divergent therapeutic strategies," Dr. Jaski and his colleagues write in the Circulation paper.
In an accompanying editorial entitled, "Deep Thoughts on Tin Men," Dr. Howard R. Levin of Cardio Technologies, Inc. and Dr. Myron L. Weisfeldt of Columbia-Presbyterian Medical Center, both in New York, New York, comment: "Initial data from the 'physiological laboratory' of patients undergoing [left ventricular assist device] support as a bridge to transplant provided the crucial information that made the concept of permanent cardiac assistance feasible. Data from studies such as the REMATCH trial [which will be the first large, controlled trial of the effect of left ventricular assist device support on survival when used as a permanent alternative to medical therapy] will change permanent cardiac assistance from concept to reality."
Circulation 1997;95:2401-2406,2340-2342. |
