A potentially lethal pattern of gene activity can identify people at high risk of dying from heart disease, say scientists.
The discovery could lead to a simple blood test showing which patients should qualify for personalised treatment and counselling.
The study of 338 patients aged 51 to 73 with coronary artery disease revealed a particular profile of gene activity in 25 of 31 participants who died.
In these patients, genes affecting inflammation were over-active while those affecting immune system T-cells were not active enough.
Dr Gregory Gibson, director of the Center for Integrative Genomics at Georgia Institute of Technology in the US, said: "We envision that with our gene expression-based marker, plus some biochemical markers, genotype information and family history, we could produce a tiered evaluation of people's risks of adverse coronary events.
"This could lead to a personalised medicine approach for people recovering from heart attack or coronary artery bypass grafting."
The results are published in the online journal Genome Medicine.
Around 15,000 genes are "expressed" - or active - in human blood. In the study, gene activity was analysed using "microarray" gene-chip technology.
Prof Gibson added: "What's new in this research is the recognition that this risk pathway exists and that it relates to particular aspects of immune system functions that include T-cell signalling.
"We went beyond the signature of coronary artery disease to really provide a signature for adverse outcomes in that high-risk population..
"Our dream would be a hand-held device that would allow patients to take a droplet of blood, much like diabetics do today, and obtain an evaluation of these transcripts that they could track at home. If we can use this information to help people adopt healthier behaviours, it will be very positive."