Award-winning study opens up new treatment options for cardiac arrhythmias
Up to two million people in Germany suffer from atrial fibrillation, the most common cardiac arrhythmia. The complaints are often characterized by irregular heartbeats such as stumbling and racing heart. Those affected also tend to have an increased formation of blood clots, which is why the risk of suffering a stroke is increased. A German team of researchers took a closer look at the triggers of this disease in a recent study. The doctors were able to derive a new therapeutic approach for treating atrial fibrillation and cardiac insufficiency from the newly gained knowledge.
The possibilities of medicinal treatment of atrial fibrillation are currently still very manageable and there is great interest in new treatment options. In many cases, atrial fibrillation is related to other heart diseases and can be a possible cause of chronic heart failure (heart failure). The central element of the study was the detailed examination of the so-called two-pore domain potassium channel K2P3.1 or TASK-1 for short, which plays a decisive role in cardiac arrhythmias. The study was awarded the August Wilhelm and Lieselotte Becht Research Prize 2017 and published in the "European Heart Journal".
Cases of atrial fibrillation increase annually
The experts assume an annual increase in new cases of atrial fibrillation. The number of diagnoses of chronic heart failure is also growing. In 2016 alone, over 455,000 cases had to be treated in hospital. Research findings on this topic have not yet been exhausted and there are currently only limited effective drug treatment options for cardiac fibrillation. "There is great interest in cardiac medicine in new approaches to treating atrial fibrillation in connection with chronic systolic heart failure," explains Prof. Dr. med. Hellmut Oelert, Chairman of the Scientific Advisory Board of the German Heart Research Foundation (DSHF).
A new promising approach
The research team around PD Dr. Constanze Schmidt was able to establish a connection between the TASK-1 potassium channel in the heart and atrial fibrillation and from this developed a promising approach for the development of new cardiac rhythm medications. The study is based on data from 175 patients with differently impaired pumping functions in the left ventricle. According to the researchers, the TASK-1 potassium channel is significantly involved in the development of so-called action potentials in the cells of the heart muscle.
Increased TASK-1 currents lead to atrial fibrillation
The action potential describes a brief change in the state of electrical excitation within the muscle cells that play an important role in the movement of the heart chambers. The researchers were able to determine that the TASK-1 potassium channel is significantly increased in patients with chronic atrial fibrillation. According to the scientists, this results in a significant increase in current in the heart muscle cells, which in turn leads to a sharp reduction in the action potential at the prechamber level.
Basis for new therapies
"If you interrupt the increased TASK-1 currents, the duration of the action potential normalizes to values of patients without atrial fibrillation," reports Constanze Schmidt in a press release on the study results. This reduction in action potential is the decisive basis for the development of atrial fibrillation. The reverse is true of the mechanism in the heart muscle cells of heart failure patients. A low TASK-1 level with a decrease in TASK-1 current goes hand in hand with an extension of the action potential duration.
Importance for cardiac medicine
These patterns provide an approach to the effect profile of new pharmacological therapies and treatment options. “We now know that atrial fibrillation and chronic heart failure are independent primary factors for the regulation of this TASK-1 potassium channel,” explains Schmidt. Other secondary influencing factors on the potassium channel are the male gender, increased body mass index over 27 and whether the patient is a smoker or not.
“Thanks to these findings, we can target rhythm medication more specifically to regulate the TASK-1 potassium channel in order to treat the heart disease. This represents a new therapeutic approach for individualized antiarrhythmic therapy, ”summarizes Schmidt. (vb)