Striking back at stroke risk

Atrial fibrillation (AF), the irregular beating of the heart’s upper chambers, is the most common cardiac arrhythmia and can often be completely asymptomatic. The condition on its own is not necessarily dangerous, but it can create complications such as blood clots, heart failure and even death. The biggest threat for patients with AF is a five-fold higher risk of stroke caused by the forming of blood clots in the heart and blocked blood vessels in the brain.1,2

An estimated 33 million people worldwide have atrial fibrillation, and the incidence and prevalence are rising fast. By 2030, 14 –17 million AF patients are anticipated in the European Union, with 120,000 – 215,000 new cases per year.3

Although the chance of stroke can be reduced by 64% with oral anticoagulants,4 about half of AF patients do not receive this treatment due to concerns about bleeding.5 Major bleeding events are a well-known side effect of this type of stroke-prevention therapy.

One method doctors use to balance the risk of bleeding with that of stroke is “clinical risk scoring.” These risk assessment tools are algorithms that add up variables about the patient’s health to arrive at a prediction. However, these scores do not always provide enough conclusive information for doctors to make the right decisions for individual patients.

A biomarker that can more objectively point to bleeding risk could therefore help improve personalised treatment. The advantage of biomarkers is that they are powerful measuring tools requiring only a routine blood test that can be performed easily and often.

In 2016, the ABC bleeding risk score was introduced, outperforming all previous scoring methods.6 ABC stands for age; biomarkers; clinical history of bleeding. The biomarkers examined are haemoglobin, TnT-hs and the novel GDF-15, which is considered the strongest predictor of bleeding risk.6

GDF-15, growth-differentiation factor-15, is a member of the transforming growth factor β family. Since GDF-15 increases in response to stress signals, its presence in a blood sample reveals inflammation, oxidative stress and cancer, as well as renal and cardiovascular pathologies.7 These disorders indicate an elevated risk of bleeding. As such, GDF-15 unmasks the underlying disease that would make a patient more prone to an event if taking anticoagulants.

A major contributor to increasing AF prevalence is the ageing global population. This is because people at higher risk of developing AF are those already living with other conditions often associated with ageing, such as hypertension, heart failure and diabetes.8 Additionally, with an estimated 1.4% of all adults over 65 living with undiagnosed AF,9 more cases of unmanaged AF create further economic strain on the healthcare system.

Better prediction would help control the burden caused by rising stroke-related costs, an increase in major bleeds and ballooning medication prices.

Testing blood samples for the GDF-15 biomarker in the blood can:

• Improve bleeding risk prediction

• Help reduce AF-related strokes

• Provide better risk discrimination than traditional risk scores

• Help curtail healthcare costs

While the number of people affected by atrial fibrillation escalates, the GDF-15 biomarker test as part of the ABC bleeding risk score means more people can be diagnosed, monitored and protected with less doubt.6

References

1. Go AS, et al. JAMA 2001; 285:2370.

2. Friberg J, et al. Am J Cardiol 2004; 94:889.

3. Chugh SS, et al. Circulation 2014; 129, 837–847.

4. Hart RG, et al. Ann intern Med 2007; 146:857-867.

5. Hsu JC et al. JAMA Cardiol 2016; 1:55-62.

6. Hijazi Z, et al. Lancet 2016; 387:2302-2311.

7. Kempf T, et al. Circ Res, 2006; 98:351-60.

8. Kirchof P, et al. Eur Heart J 2016; 37:2893-62.

9. Lowres N, et al. Thromb Haemost 2014; 110:213-22.