Sildenafil, also known as the erectile dysfunction drug Viagra, may give a boost to underdeveloped hearts in children and young adults with congenital heart defects. Researchers from The Children's Hospital of Philadelphia report that sildenafil significantly improved echocardiographic measures of heart function in children and young adult survivors of single ventricle heart disease palliation.
"Although researchers will need to evaluate clinical benefits over a longer period with a larger number of patients, this finding offers a potential advance in the management of patients with these types of heart defects," said study leader David J. Goldberg, M.D., a pediatric cardiologist at The Children's Hospital of Philadelphia.
The study appeared online recently in the journal Pediatric Cardiology.
The researchers randomly assigned 27 children and young adults at Children's Hospital to receive either sildenafil or a placebo for six weeks. After a six-week break in treatment, the subjects were switched to the opposite treatment course. The study team used echocardiograms to measure myocardial performance index (MPI), an indicator of the heart's overall ability to pump blood.
The patients in this double-blind, short-term study, who had a mean age of 14.9 years, had undergone a Fontan operation in early childhood, a mean of 11.3 years previously. The Fontan surgery redirects blood circulation in patients born with a severely underdeveloped ventricle, one of the heart's two pumping chambers. The operation is the third in a staged series of surgeries for life-threatening single-ventricle defects.
Although surgical advances over the past 20 years have dramatically improved survival for single-ventricle defects, patients with the condition continue to have long-term illness and risk of early death. The staged surgeries do not recreate normal heart circulation, but instead redirect blood flowing from the veins directly to the lungs, bypassing the heart. However, blood vessels in the lungs develop resistance to this blood, often reducing a patient's ability to tolerate exercise.
Sildenafil, which reduces blood vessel resistance to the flow of blood, is already used to treat pulmonary hypertension (high blood press in lung vessels), as well as erectile dysfunction. Because sildenafil has also shown promise as a treatment for adults with heart failure, the Children's Hospital researchers are exploring whether it may benefit younger patients with certain types of congenital heart disease.
The current study is part of a broader phase 2 clinical trial at The Children's Hospital of Philadelphia, the Sildenafil After the Fontan Operation (SAFO) trial. A previous study from the same research team, published in March 2011, found improvements in exercise performance, as measured by ventilator efficiency, in children and young adults with single-ventricle disease who took sildenafil compared to those who took placebo.
The current study was the first to show that sildenafil improved echocardiographic measures of ventricular performance in children and young adults with single-ventricle physiology. The biological mechanisms that affect ventricular performance are not fully understood, said Goldberg, but he noted that studies in other patients with heart disease suggest that inhibiting the abnormally high levels of the enzyme phosphodiesterase E5 (PDE5) may produce the physiological benefits seen in the single-ventricle patients.
Goldberg cautioned that further research should be pursued to determine if the observed improvements in ventricular performance persist beyond the short term and if they provide clear quality-of-life benefits. "If sildenafil is safe over the medium and long-term, and if it produces durable functional improvements, patients with single-ventricle heart disease could have their first effective long-term treatment," he added.
Children's Hospital of Philadelphia: http://www.chop.edu
This press release was posted to serve as a topic for discussion. Please comment below. We try our best to only post press releases that are associated with peer reviewed scientific literature. Critical discussions of the research are appreciated. If you need help finding a link to the original article, please contact us on twitter or via e-mail.
Treating patients with the deadly Ebola virus takes doctors, drugs, and a whole lot of chlorine.
For decades, smokers in eastern Europe have used cytisine from laburnum trees to help them quit. Good results in a new trial could make cytisine much more popular
The National Institutes of Health has approved requests for waivers from a moratorium on experiments that aim to make the virus that causes Middle East respiratory syndrome more infectious in mice.
It's all fun and games until someone dislocates a knee, wets himself or has a stroke
Use of synthetic drugs, like bath salts, by young people continues to decline across the nation, according to a study by the University of Michigan.
Researchers are struggling with how to balance the benefits and risks of genetic experiments that can give viruses new talents for causing infections.
For all the medicine they provide at this center, physicians and staff from Doctors Without Borders spend as much time encouraging the patients to eat, drink, and keep fighting. Every patient gets a standard regimen of antibiotics, paracetemol and other pain medications, vitamins, oral rehydration therapy or intravenous fluids. Drugs can control nausea for those who need them; everyone gets antimalarials.
Dengue sickens millions of people each year, and there's no cure. Now scientists have found powerful antibodies that stop the virus. Their discovery offers a road map to develop a simple vaccine.
British doctors make the case for playing music during an operation
Doughnuts? No thank you. An edible powder made from stuff our gut bacteria excrete can stop people gaining weight when taken daily