TUESDAY, Dec. 16, 2003 (HealthDayNews) -- Preliminary results of a new cell transplant technique show promise for helping repair hearts damaged by a heart attack.
In the first study of this type, doctors in the Netherlands were encouraged that a technique for transplanting muscle cells into patients' damaged hearts through their arteries appears feasible.
In the technique, researchers collected thigh muscle cells from five patients, cultured them, transplanted them via threaded catheter through blood vessels, and injected them into scarred heart muscle tissue.
Although the technique is seen as minimally invasive, the study has not proven the therapy actually repairs damaged tissue.
"Is it effective? It's hard to tell in this early stage, but we see improvement in some patients that we can measure in different ways," says study author Dr. Pieter C. Smits. "But the numbers we treated were limited, so are too low to make definite conclusions. What we need is to do a larger randomized study that will bring final proof."
"It is promising, but still I think we need to be very cautious," Smits adds.
The study found that compared with baseline, the left ventricular ejection fraction (a measure of the heart's ability to pump blood) increased from 36 percent to 41 percent after three months, and then to 45 percent after six months.
All the cell transplantation procedures were uneventful, and it seems no serious adverse events occurred during follow-up observation.
However, one patient received an implantable cardioverter-defibrillator after transplantation because of arrhythmia, or seriously irregular heartbeat.
"It is difficult to say whether the arrhythmias are a result of these cell injections or are a result of the natural course of the disease in these patients. Larger, randomized trials are needed to get answers to this crucial question," Smits says.
The problem of arrhythmia has been seen in previous studies of cell transplantation, the researchers note.
Writing in an accompanying editorial, Dr. Raj R. Makkar and colleagues from the Cedars-Sinai Medical Center and the University of California at Los Angeles praise the work, calling it an exciting feasibility study. However, they sound a cautionary note as well.
Makkar suggests that, for now, studies of this sort of cell transplantation to treat heart failure should be restricted to patients who have implantable cardioverter-defibrillators to protect them against a potential risk of arrhythmias.
"You have to remember that these results are in the very earliest of stages, almost preliminary stages," says Dr. Hans Bonnier, a cardiologist with the Catharina Hospital, also in The Netherlands. "To bring it around to a solution to myocardial infarction, it's a just a little bit too early."
Bonnier says patients shouldn't get too enthusiastic yet. "They get a lot of hope and they think it's absolutely fantastic and think all problems are solved," he says. "And then maybe it may not be effective."
The study appears in the Dec. 17 issue of the Journal of the American College of Cardiology.