Most victims of heart attack or stroke have little or no warning before they suffer a potentially fatal attack. But researchers writing in the Journal of the American Medical Association say a simple blood test might identify those likely to suffer a heart attack or stroke.

The research team says it linked the risk to the presence of a biomarker called NT-proBNP in the blood.

Patients with the highest level of the substance were up to eight times more likely to die or experience serious heart-related illness than those with the lowest levels of NT-proBNP.

Patients with the highest levels of NT-proBNP tended to be older and had other high risk factors, such as diabetes and high blood pressure. They were also more likely to be on strong medication such as beta-blockers and statins, according to the study.

NT-proBNP stands for N-terminal prohormone Brain-type Natriuretic Peptide. It has previously been identified as a biomarker for heart failure, but this study has found it to be a predictor of other, serious cardiac-related illness.

Coronary Heart Disease is the single leading cause of death among Americans, according to the American Heart Association. One in five deaths is caused by CHD. More than one million heart attacks are reported every year.