In the US alone, around 300,000 patients receive pacemakers each year, but the devices come with certain side effects, such as infection of the leads connecting the pacemaker to the heart.
The team's findings, which are published in the journal Science Translational Medicine, are the culmination of a dozen years of research aimed at creating biological solutions for pacemaker patients with heart rhythm disorders.
The new gene transplant procedure transforms heart cells into a biological pacemaker, regulating the heartbeat.
The American Heart Association explain how, in the absence of the heart's natural pacemaker functions, an artificial pacemaker works.
The heart's natural pacemaker is known as the sinoatrial (SA) node or sinus node, which is a small clump of specialized cells in the upper chamber of the heart. This node makes the electrical impulses that prompt the heart to beat.
When an electrical impulse or signal moves across a chamber of the heart, it contracts. However, the signal must travel down a specific path to reach the heart's lower chambers; when the SA is defective, the heart could beat too fast, too slow or irregularly. Additionally, rhythm problems can happen due to a blockage of the heart's electrical pathways.
This is where an artificial pacemaker comes in, to send electrical impulses to the heart to help it pump properly. However, the researchers have come up with a procedure that uses the heart's own cells to regulate the rhythm.
"We have been able, for the first time, to create a biological pacemaker using minimally invasive methods and to show that the biological pacemaker supports the demands of daily life," says Dr. Eduardo Marbán, director of the Cedars-Sinai Heart Institute and leader of the research team.
"We also are the first to reprogram a heart cell in a living animal in order to effectively cure a disease," he adds.
Transplanted gene resulted in stronger heartbeat
For their study, the team injected laboratory pigs that had complete heart block with a gene called TBX18, through a minimally invasive procedure using a catheter.
On the very next day, the team observed that the pigs who received the gene had "significantly" faster heartbeats, compared with the pigs who did not receive the gene, and this stronger heartbeat remained throughout the entire 14-day study.
Dr. Marbán explains that they originally thought biological pacemaker cells "could be a temporary bridge therapy for patients who had an infection in the implanted pacemaker area," but their results suggest they might be able to develop a long-lasting biological treatment.
He adds that if future research ends in success, their procedure could be sent to human clinical studies in 3 years or so. Additionally, these pacemaker cells could potentially help infants that are born with congenital heart block.
Dr. Eugenio Cingolani, director of the Heart Institute's Cardiogenetics-Familial Arrhythmia Clinic, explains that babies in the womb are unable to have a pacemaker, "but we hope to work with fetal medicine specialists to create a life-saving catheter-based treatment for infants diagnosed with congenital heart block. It is possible that one day, we might be able to save lives by replacing hardware with an injection of genes."
Shlomo Melmed, dean of the Cedars-Sinai faculty, speaks of how this new treatment will transform gene therapy:
"This work by Dr. Marbán and his team heralds a new era of gene therapy, in which genes are used not only to correct a deficiency disorder, but to actually turn one kind of cell into another type."
Medical News Today recently reported on the world's smallest ever pacemaker that was implanted in a patient in the UK. The pacemaker is just one tenth the size of traditional pacemaker models.