Atrial fibrillation: New study results on NOAKs

Atrial fibrillation is one of the most common cardiac arrhythmias. Without treatment, serious consequences such as stroke follow. A new study now confirms the advantages of certain drugs over conventional ones.

In atrial fibrillation, the heartbeat is persistently irregular and usually accelerated. The frequency in the general population is one to two percent. However, it increases with age. For example, the frequency rises to up to 15 percent in 70- to 80-year-olds. At first, atrial fibrillation is not noticed. Without appropriate therapy, blood clots, so-called thromboembolic complications, can occur. If atrial fibrillation is left untreated, the risk of stroke increases fivefold compared to healthy people. The risk of heart failure is three times higher.

To minimise this risk, it is important to choose the right drug treatment. Patients usually have two options. One is the so-called vitamin K antagonists (VKA) or the new oral anticoagulants (NOAK), which have only been on the market for a few years but have been used more and more in the recent past. Vitamin K plays an important role in blood clotting. This blood clotting is to be inhibited in the patients described above. The VKA block the effect of vitamin K and thus provide the desired effect. The mode of action of NOAKs is different. Here, there is no intervention in the protein production process as with the VKAs, but the NOAKs enter into a direct connection with certain blood clotting factors and inhibit their function. Both types of medication are also commonly called “blood thinners”, although the term is not entirely correct due to the mode of action described above.

Fewer haemorrhages and deaths

A recent Danish cohort study shows a safety advantage of NOAKs over VKAs in newly-treated patients with atrial fibrillation. Intracranial bleeding occurred less frequently with the NOAK drugs investigated in the study than with VKA therapy. Also for deaths, where both bleeding events and fatal strokes or other death events are included, there were better results for NOAKs than for the VKA drugs studied. One single study should not be overestimated, especially since it is only a cohort study. But this is another indication of the safety of NOAKs.

“In terms of patient comfort, there are further advantages of NOAKs over VKA. With VKA or corresponding generics, the INR value has to be measured regularly,” explains the Berlin cardiologist Dr Rainer Ruf from Friedrichshain. The INR value (International Normalised Ratio) shows how long the blood clotting time is prolonged by taking the anticoagulant. The measurement results provide information on how the dose of the medication needs to be adjusted. Such monitoring is not necessary when taking NOAKs.