View Full Version : Post heart attack recovery may not be aided by stem cell injections

11-14-2011, 04:39 PM
Post heart attack recovery may not be aided by stem cell injections, but trial demonstrates promise
November 14, 2011

University Hospitals Case Medical Center researchers could still be close to giving heart attack patients a second chance…just not as they originally thought.

LateTIME was a study of adult stem cells (autologous) harnessed from bone marrow that were believed to have the ability to improve heart function after an attack if injected into the heart within two weeks of the attack.

Results are being released today at American Heart Association Scientific Sessions and published this week in Journal of the American Medical Association (JAMA).

The results have shown the injections within that timeframe were not favorable, but the concept showed great promise, according to an accompanying JAMA editorial that assessed the trial.

The therapy still shows promise for recovering lost or damaged heart tissue resulting from a heart attack. Both UH Case Medical Center's Drs. Dan Simon and Marco Costa, co-investigators in the LateTIME study, are currently participating in a similar trial, "TIME" that already has reduced the time between attack and stem cell injection.

The pair is optimistic the time variable adjustment in the new trial will lend favorable outcomes. Dr. Simon is Chief, Cardiovascular Medicine at UH Case Medical Center and the Herman K. Hellerstein Professor of Cardiovascular Research, Case Western Reserve School of Medicine. Dr. Costa is the director of the Interventional Cardiovascular Center and Research & Innovation Center at UH Case Medical Center as well as a professor of medicine at Case Western Reserve University School of Medicine.

The shared theories in both trials is that the specialized cells could have the ability to promote blood vessel growth, prevent cell death and transform themselves into a number of tissues, including muscle. After an acute heart attack, a remodeling process was initiated in the heart in an attempt to compensate for the damaged areas.

Researchers surmised that the condition of the heart muscle several weeks after the attack may differ considerably from the heart muscle in the acute stage setting. For some patients delaying the delivery of stem cells by two to three weeks may have been better than initiating the treatment during the acute phase.

All patients underwent baseline assessments that included medical history, physical exam, electrocardiogram, blood draws, echocardiogram and MRI tests. Participants were then assigned randomly to receive the stem cells or placebo within the aforementioned two to three week timeline.

The morning of stem cell or placebo infusion, a blood draw and bone marrow aspiration procedure of the hip bone are conducted to collect the stem cells. Later the same day, either stem cells or placebo are then infused through a catheter and directly into the damaged area of the heart.
Following the first 24 hours of the infusion, participants wear a small ECG machine, or Holter monitor. Additionally, patients record their body temperature twice a day for 30 days post infusion. Follow up visits at months one, three, six, 12 and 24 where baseline assessment testing are conducted.

Provided by University Hospitals Case Medical Center

11-14-2011, 04:44 PM
Delayed stem cell therapy following heart attack is safe but not effective
November 14, 2011

NIH-funded trial shows that therapy with bone-marrow derived cells does not improve heart function after six months; future clinical benefits still possible.

Stem cells obtained from bone marrow, known as BMCs, can be safely injected into people 2-3 weeks following a heart attack, reports a new clinical trial supported by the National, Heart, Lung, and Blood Institute (NHLBI), part of the National Institutes of Health. However, while safe, the BMCs did not improve heart function six months after their administration.

This study, called LateTIME (Transplantation In Myocardial Infarction Evaluation), is the first trial to rigorously examine the safety and potential benefits of extending the timing of stem cell delivery to 2-3 weeks following a heart attack. The results will be presented Monday, Nov. 14, at the 2011 Scientific Sessions of the American Heart Association Meeting in Orlando, Fla. They will also appear online in the Journal of the American Medical Association.

"Although treatment and survival following a heart attack have improved over the years, the risk of heart failure following a heart attack has not decreased," said Susan B. Shurin, M.D., acting director of the NHLBI. "Stem cell therapy is a promising direction for repairing the damage done by a heart attack. We do not fully understand the optimal use of these cells; studies like LateTIME will help us understand how to perform and monitor these procedures.''
Previous studies have suggested that injecting BMCs into the heart could improve cardiac function following a heart attack and perhaps reduce the need for future hospitalizations and heart surgeries. In contrast to LateTIME, earlier studies delivered BMCs within a few days of the heart attack. In many cases, a patient will not be able to get such immediate treatment, due to poor health following a heart attack or because the hospital providing care doesn't have a stem cell therapy program.

Between July 2008 and February 2011, LateTIME enrolled 87 people with heart attacks who had undergone cardiac procedures to open blocked arteries. The participants all had moderate to severe impairment in their left ventricle, which pumps oxygen-rich blood to the body. All the participants had stem cells taken from bone marrow in their hip for processing. LateTIME researchers developed a standardized method of processing and purifying these stem cells, and this was the first BMC trial to provide a uniform dose of BMCs to each participant. The study then randomly assigned the participants to receive either their purified BMCs or inactive (placebo) cells.

After six months, improvement of heart function was assessed by measuring the percentage of blood that gets pumped out of the left ventricle during each contraction (left-ventricular ejection fraction, or LVEF) by cardiac MRI. There were no significant differences between the change in LVEF readings between baseline and six months in the BMC (from 48.7 percent to 49.2 percent) or placebo (from 45.3 percent to 48.8 percent) groups.

"This does not mean that stem cell therapy will only work if done immediately following a heart attack or that later beneficial effects on clinical outcomes won't emerge," noted Lemuel A. Moyé, M.D., Ph.D., professor of biostatistics at the University of Texas School of Public Health, Houston, and a LateTIME researcher. "Many factors influence how the heart responds to stem cells, which highlights the critical need to continue rigorous tracking studies in this area."

Moyé added that the health of the study participants will continue to be evaluated for two years, so the BMC therapy may yet demonstrate health benefits such as a lower risk of subsequent heart attacks or heart failure, in which the heart cannot pump enough blood to meet the body's needs.

LateTIME is one of three heart stem cell trials being undertaken by the NHLBI-sponsored Cardiovascular Cell Therapy Research Network. The other trials under way by this multicenter consortium are TIME, which is comparing the effectiveness of stem cell therapy delivered at three days versus seven days following a heart attack, and FOCUS, which is examining stem cell therapy in people with chronic heart failure.

More information: Resources:
What is a heart attack: http://www.nhlbi.n … heartattack/
What is heart failure: http://www.nhlbi.n … s/topics/hf/
What is coronary angioplasty: http://www.nhlbi.n … angioplasty/
Provided by National Institutes of Health