NOACs are recommended by the ESC guideline as the primary choice for patients with oral anticoagulation. Compared to the previous standard warfarin, they offer great advantages in stroke prevention, as randomized clinical trials (RCT) have shown. But what about the real world in practice? What do the data say and how valid are they?
In contrast to RCT, real-world data generally do not allow statements to be made on correlations and causalities. The reason for this is that Real World studies rely on pre-selected study populations and treatment methods. There is certainly a so-called selection-based bias in this type of study.
Real world data is based on preselected data:
Doctors should bear this limitation in mind when interpreting data from real-world studies.
NOAC, as confirmed by real-world studies, e.g. from the USA or Taiwan, are safe and often reduce the risk of strokes more significantly than VKA. In the vast majority of cases, these drugs also have a more favorable profile with regard to bleeding events.
A large meta-analysis with 28 included real-world individual studies (15,000 - 600,000 patients) showed a significant reduction in the risk of stroke under NOAC as well as less severe bleeding events than with the comparison drug warfarin. Bleeding in the gastrointestinal tract appears to be more frequent with dabigatran and rivaroxaban than with VKA.
Overall, the NOAC data from RCTs and Real World studies are highly consistent. This supports the assumption that NOACs are drugs that are indeed better than VKA. This makes NOAC the substances of choice in the real world of practice for anticoagulant treatment of patients, which is also reflected in the ESC guideline recommendation.
In numerous studies, NOACs have been classified as superior to classic VKA medications. The data from the RCT are also confirmed worldwide by the first Real World studies.
Nevertheless, treating physicians must always be aware that all currently available Real-World NOAC studies are based on selective study groups. So be skeptical despite all the euphoria and also consider that the results, as exciting as they may be, are not easily transferable to other study groups or patients.
A special group of patients currently being investigated in detail in a study from Germany are older, comorbid AF patients. These are usually > 65 years old and take on average more than 15 medicines. Whether this will affect the safety and effectiveness of NOAC is still largely unknown.
Sources:
Are NOACs really better than VKA in the real world?, 27.08.2018, ESC Munich