Atrial fibrillation: better outcomes with diamonds

Atrial fibrillation is an irregular heartbeat that can lead to blood clots and trigger strokes. To correct the condition, physicians use medication or surgical intervention by means of catheter ablation. This surgical method on the beating heart is a standard and safe procedure but there is always room for improvement.

In this MEDICA-tradefair.com interview, Prof. Philipp Sommer talks about an innovative intracardiac catheter with industrial-grade diamonds that could make the treatment of atrial fibrillation even faster and safer.

Professor Sommer, what is the pathophysiology of atrial fibrillation?

Prof. Philipp Sommer: Cardiac muscle activity is usually controlled by electrical signals that are generated by the sinoatrial node. Atrial fibrillation occurs when certain areas of the heart experience too many or chaotic electrical signals. The result is a fast and irregular heart rhythm.

How does catheter ablation correct this heart rhythm problem?

Sommer: First, we have to make our way to the areas of disruption that cause the arrhythmia. This requires special catheters and sheath technology. Next, we use different types of energy such as thermal ablation or cryoablation to cauterize the respective nerve tracts at these points. The cauterized tissue no longer transmits the electrical signals that cause the irregular heartbeat. The procedure usually takes one to three hours and requires a brief hospital stay of one to two days. Nearly 70 percent of patients no longer experience an irregular heart rhythm after the procedure.

HDZ NRV was the first heart clinic in Germany to use a novel catheter ablation system called "Diamond Temp". What is its advantage over other catheter systems?

Sommer: The catheter-based system features industrial-grade diamonds. They have a higher thermal conductivity than platinum or gold, which are the typical alloys used in other catheters. This gives us faster and more accurate temperature feedback from the cauterized area of the cardiac muscle. Software uses the feedback to modulate the generator that delivers the energy. This enables us to better control tissue ablation and speed up the process.

The bottom line is that this shortens the time a surgeon needs to aim the catheter tip at the area of abnormal heart tissue. Other catheters require about 30 seconds, while this catheter system only needs five seconds to be successful. This increases the probability of effective lesion formation and delivers a high quality catheter ablation result.

Is there a difference in how this new catheter is applied compared to other systems?

Sommer: All cardiac catheters differ slightly in their features though this is not something that makes them unique. Apart from the time variation, the actual procedure is nearly the same.

Does it avoid or reduce the possible risks and complications of the procedure?

Sommer: There is no scientific proof of that yet. However, that is because cardiac ablation complications are actually very rare. The rate of bleeding at the site is around 0.8 percent, while the risk of stroke ranges around 0.4 percent. Together, they affect approximately one percent of treated patients.

To date, studies for the new catheter have included just a few hundred patients, who have shown no clear reduction in complications. Again, that is because catheter ablation is already a low-risk and safe procedure that requires a very large number of patient participants to detect a statistically significant change.

Of course, the hope is that there is a general reduction of complications if the lesions can be created in a shorter amount of time because the catheter is a foreign object and does not have to remain inserted in the heart for as long as previous methods require. But again, these are theoretical deductions that have not yet been proven.

What would be the incentive to use the new catheter system at this point in time?

Sommer: The notion of a more precise lesion formation and presumably longer lesion durability give the system an edge as this might lower the recurrence rate, which is currently around 30 percent. The other point is that the duration of the intervention can be kept as short as possible. At the moment, the actual ablation process takes between 25 and 30 minutes. This new technology could feasibly shorten procedure time to 10 minutes.