Medical

Protein infusion could reduce heart failure risk after heart attack

Protein infusion could reduce ...
Researchers have found a protein that can improve heart scar tissue in large animals and are looking towards human trials
Researchers have found a protein that can improve heart scar tissue in large animals and are looking towards human trials
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Researchers have found a protein that can improve heart scar tissue in large animals and are looking towards human trials
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Researchers have found a protein that can improve heart scar tissue in large animals and are looking towards human trials

Heart disease is the biggest killer in the Western world. A part of the problem is that even if one survives a heart attack, damage to the heart muscle results in the formation of thick scar tissue that can increase the chance of heart failure. Now researchers have found a way to improve the quality of the scar tissue in animal models, resulting in improved heart function following a heart attack.

The research centers on a protein therapy called recombinant human platelet-derived growth factor-AB (rhPDGF-AB), which had previously been shown to improve heart function in mice that had suffered a heart attack. In a new study aimed at bringing the treatment closer to human trials, a team set out to discover if it produced similar results in large animals, namely pigs.

The researchers from the Westmead Institute for Medical Research (WIMR) and the University of Sydney found that when pigs that had suffered a heart attack received an infusion of rhPDGF, it did indeed prompt the formation of new blood vessels in the heart and led to a reduction of potentially fatal heart arrhythmia.

"This is an entirely new approach with no current treatments able to change scar in this way," says Associate Professor James Chong who led the research. "By improving cardiac function and scar formation following heart attack, treatment with rhPDGF-AB led to an overall increase in survival rate in our study."

Chong says that although the treatment didn't affect the overall size of the scar, rhPDGF-AB improved heart function after the heart attack by triggering an increase in the alignment and strength of scar collagen fiber.

Current approaches focus on reducing scarring by restoring blood and oxygen supply to the heart as quickly as possible, but despite improving clinical outcomes, up to one quarter of patients who receive such treatment will still go on to develop heart failure within a year of suffering their first heart attack.

Additionally, there are many people who aren't even aware they've had a heart attack or are unable to get to a hospital quickly, so a treatment that can be administered after the fact holds great potential.

"While we have treatment protocols in place, it's clear that there is an urgent, unmet need for additional treatments to improve patient outcomes particularly after large heart attacks," Chong says.

The team needs to conduct additional animal studies to establish safety and dosing, but hopes to start human trials "very soon."

"This project has been developed over more than 10 years and we now have compelling data in two species for the effectiveness of this treatment," says Chong, adding, "we now hope to further investigate the treatment, including whether it could be used in other organ systems impacted by scar tissue, such as the kidneys."

The team's research appears in Science Translational Medicine.

Source: University of Sydney via EurekAlert

2 comments
Douglas
""Animal research is something that we need to do in medical research. We don't take it lightly," Professor Chong said." Really? Here's reality... The history of heart research shows that animals suffered for nothing as always... Experiments on dogs to develop transplant techniques were disastrous. Hundreds of dogs were used yet the first human patients died because of complications which arose when the technique was applied to the first human patients. (Dr Albert Iben, Stanford University cardiac surgeon reported in the Erie Daily Times, May 23 1968.) By 1980, 65% of patients survived more than a year as a result of increased skill gained through clinical experience. (Lancet, March 29 1980, pages 687-688.) MONITORING EEG The electroencephalograph is not a result of animal experimentation. (M. Beddow Bayly, Clinical Medical Discoveries, NAVS, 1961.) FLOATING CARDIAC CATHETER Dr Forssman used his own forearm to develop cardiac catheterization and his technique was completed through clinical trials with human patients. (M. Beddow Bayly, Clinical Medical Discoveries, NAVS, 1961.) CARDIOPULMONARY RESUSCITATION Mouth to mouth resuscitation was developed by Kouwenhoven, Jude and Knickerbocker by experimenting on cadavers in the morgue. Their technique is the standard form of cardiopulmonary resuscitation used by the American Red Cross. (Comroe, Exploring the Heart: Discoveries in Heart Disease and High Blood Pressure, Norton and Company, 1983, page 1162.) THE CAGED BALL VALVE Doctors Starr and Edward almost discarded the caged ball valve as it killed all their experimental dogs. It was however successful on human beings. (A. Starr, "Mitral Replacement: Clinical Experience with a Ball-Valve Prosthesis", Annals of Surgery, 154(4):740, 1961.) VENTILATION OF OPEN THORAX Doctors Ivan Magill and E.S. Rowbotham, working with World War I casualties at Sir Harold Gillie's plastic surgery hospital in Sidcup, Great Britain developed the technique of delivering anaesthetic gas through a single endotracheal tube under positive pressure controlled by the patient's breathing. They performed no animal experiments. (R.G. Richardson, The Surgeon's Heart: A History of Cardiac Surgery, William Heinemann Medical Books Ltd, page 101.) DEFIBRILLATION Fibrillation of the ventricles is life-threatening. Reverend John Wesley in the 18th Century through clinical observations successfully used electrotherapy to stop fibrillation in human patients. More than a century later in 1899 Presost and Batteli "re-proved" what Wesley had developed, by using electric shock to reverse ventricular fibrillation in dogs. William B. Kouwenhoven of Johns Hopkins University is sometimes credited by pro-vivisectionists for developing a closed-chest defibrillator for dogs and then for human use in 1957. However clinician Dr P. Zoll had developed closed-chest resuscitation on patients in 1956. Once again Kouwenhoven repeated what Zoll had discovered through human observations and falsely credited animal research for the advance. (L. Wertenbaker, To Mend the Heart, the Viking Press, 1980, page 178.); (J.H. Comroe, Exploring the Heart: Discoveries in Heart Disease and High Blood Pressure, W.W. Norton and Company, 1983, page 159.); (L.E. Meltzer, Textbook of Coronary Care, The Charles Press Publishers Inc., A Prentice Hall Company, 1980, page 4.) ELECTIVE CARDIAC ARREST For "restarting" the heart once again animal experiments gave misleading results. Though a technique was shown "effective" in animals, it was discarded for use in humans because of "many problems, consisting of pain, burns and inability to keep up continuous stimulation for a prolonged period". (W. Lillihei, "The Treatment of Complete Heart Block by the Combined Use of a Myocardial Electrode and an Artificial Pacemaker", Surgical Forum, 43rd Clinical Congress, Vol. VII, American College of Surgeons, Chicago, 1957.) VASCULAR ANASTOMOSIS In 1935 Dr Claude S. Beck pioneered the surgical technique to increase the blood supply to the heart muscles when blood became blocked in the coronary arteries. Beck whose success was based on clinical observations said though he had conducted thousands of animal experiments they were useless, that his only useful knowledge came from clinical studies. The Beck operations were carried out for 25 years before being superseded by the clinical development of new operations. (T. Preston, Coronary Artery Surgery: A Critical Review, Raven Press, 1977, page 9.) MYOCARDIAL PRESERVATION TECHNIQUES Scientists at the Middlesex Hospital and Medical School recently isolated individual heart cells from human heart muscle. These cells are useful in research into heart disease and in the preservation of heart (myocardial) tissue for cardiac surgery, with the advantage that results are directly applicable to patients because as the researchers stated: "... it is difficult and often misleading to extrapolate experimental results in animal tissues to man." (T. Powell, et al, BMF, October 17 1981, pages 1013-1014.) HEART TRANSPLANT OF BABY FAE AT LOMA LINDA MEDICAL SCHOOL, CALIFORNIA 1984 At the time of this operation it is reported that Bailey had no experience in human heart transplants but had experimented with many animals performing over 160 cross-species transplants. According to Dr Martin Ruff, an immunologist at University College, London, rejection of the baboon heart was inevitable because there are no antigens in common between baboons and humans. (But as Dr Fadali has told us "animal experiments inevitably lead to human experiments". The untold amount of suffering this flawed methodology caused to Baby Fae was the result of human experimentation.) (New Scientist, November 29 1984.) ARTIFICIAL HEART It is emphasised in many sources that medical progress has been delayed because of the vast difference in dogs and human beings and that dog experiments were a failure in this area. The conduction system in dogs is less likely to clot than in human blood; dogs walk on four legs, thereby placing less stress on the circulatory system than upright human beings; the ventricles in dogs are opposite to the human system; and animal recipients of artificial hearts are healthy before the operation. There are many other variables noted elsewhere in this work. The first recipient of an artificial heart, Barney Clark, survived a miserable 112 days kept alive against his wish to be allowed to die, until he expired from kidney collapse. (C.F. Scott,"Appropriate Animal Models for Research on Blood in Contact with Artificial Surfaces", Annals N.Y. Academy of Science, 516, 1987, pages 636-637.); (C.F. Scott, The Physiologist, 31 (3), 1988, page 53.); (Hans Ruesch, One Thousand Doctors (and many more) Against Vivisection, 1989, page 28.) Elsewhere in this work it is recorded how the discovery of insulin and the success of open heart surgery, and organ transplants were developed despite confusion arising from experiments on dogs (and other animals). As revealed under the section on congenital heart defects the success of the "blue baby" operation was developed through clinical observation of human patients. Similarly the pacemaker for complete heart block was developed through investigation of those afflicted with the condition. THE PACEMAKER Each of the techniques made to contract or stimulate the ventricles in attempts to "pace" the human heart was tested on dogs and shown "effective", even heralded as a success, however they were "quickly discarded in patients because of the many problems, consisting of pain, burns and inability to keep up continuous stimulation for the prolonged period". Dr C. Walton Lillihei pioneer of the pacemaker, seeing his method which was developed on dogs fail to cross the species, devised, through observing his patients, a method of "stitching electrodes directly on to the heart, leading them through the chest and running a pulsed current through them". "The development of artificial pacemakers for complete heart block grew out of direct studies of human patients suffering from ventricular septal defect." (W. Lillihei, "The Treatment of Complete Heart Block by the Combined Use of a Myocardial Electrode and an Artificial Pacemaker", Surgical Forum, 43rd Clinical Congress, Vol. VIII, American College of Surgeons, Chicago, 1957, page 360.) Also refer L. Wertenbaker, To Mend the Heart, The Viking Press, 1980, page 181; and R.G. Richardson, The Surgeon's Heart: A History of Cardiac Surgery, William Heinemann Medical Books Ltd, page 101. OPEN-HEART SURGERY The heart-lung machine was the most critical development in open-heart surgery for it takes over the function of the patient's heart and lungs during open heart operations. John H. Gibbon of Philadelphia, U.S.A. who developed a heart-lung machine on dogs abandoned his project when two patients died, admitting that it was unsafe for human beings. J.W. Kirklin of the Mayo Clinic, without the use of animals and using careful clinical trials made a heart-lung machine which was successful on human beings. (H. McLeave, The Risk Takers, Holt, Rinehard & Winston, 1962, page 70.)
eMacPaul
@Douglas, so you think we should do all the tests on humans, and needlessly kill hundreds of humans due to unforeseen complications instead?