Researchers in the US have discovered that testing the blood of patients with stable coronary heart disease for high levels of the biomarker NT-proBNP is a reliable predictor of serious and fatal heart-related incidents, including heart failure and strokes.

The research is reported in the current issue of the Journal of the American Medical Association.

Led by Dr Kirsten Bibbins-Domingo of the Unversity of California, San Francisco, the researchers found that patients with stable heart disease with the highest level of NT-proBNP in their blood (the upper quartile or 25 per cent) were up to 8 times more likely to die or experience serious heart-related events, such as heart attacks, heart failure and strokes compared to those patients with the lowest level of the biomarker (the lowest 25 per cent).

When they adjusted the figures to take into account a range of other risk factors, such as ECG measures and other biomarkers, they found that the NT-proBNP effect was still there at a reliable, but lower level – the risk of adverse outcomes was still three times more likely for the highest NT-proBNP concentrations.

They also found that patients with the highest level of NT-proBNP concentration tended to be older, their condition was more serious and they had higher overall risk factors such as diabetes and blood pressure. They were also more likely to be on strong medication such as beta-blockers and statins.

The study looked at just under 1,000 Californian outpatients with stable heart disease who were enrolled in the Heart and Soul programme and attending a range of medical centres and clinics.

NT-proBNP stands for “N-terminal prohormone Brain-type Natriuretic Peptide” and is already a known biomarker for heart failure blood tests. However, this is the first study where it has been used to predict heart failure and other serious and fatal cardiac events. The presence of the peptide in the blood indicates that the heart muscle is under stress in some way.

Coronary heart disease (CHD), also called coronary artery disease, is where the arteries that supply blood to the heart itself (as opposed to that which the heart pumps around the body) become narrow as a result of years of build up of plaques. CHD is the single leading cause of death among Americans. It causes heart attack and angina. One in 5 deaths is caused by CHD. 1.2 million heart attacks are reported every year, and 40 per cent of people who have one will die from it.

Heart failure is when the heart, for functional or structural reasons, is unable to pump enough blood around the body. One reason could be due to coronary artery disease, another reason could be irregular heart beat, which upsets pumping rhythm and throughput of blood in the heart. There are 5 million Americans living with the disease, and 550,000 new cases are found each year.

“N-Terminal Fragment of the Prohormone Brain-Type Natriuretic Peptide (NT-proBNP), Cardiovascular Events, and Mortality in Patients With Stable Coronary Heart Disease.”
Kirsten Bibbins-Domingo, PhD, MD; Reena Gupta, MD; Beeya Na, MPH; Alan H. B. Wu, PhD; Nelson B. Schiller, MD; Mary A. Whooley, MD.
JAMA. 2007;297:169-176.

Click here for more information on BNP and NT-proBNP testing (Lab Tests Online).

American Heart Association

Written by: Catharine Paddock
Writer: Medical News Today