Abstract 12340: Enhancing the Diagnosis of Coronary Artery Disease via Deep Sequencing of Whole Blood
Objective: To discover specific and unique RNA transcripts expressed in patients who develop coronary artery disease (CAD).
Methods: Venous whole blood was collected from 110 patients without a history of CAD prior to undergoing left heart catheterization. Coronary angiograms showed the absence or presence of CAD, defined as any degree of atherosclerosis. To identify RNA TRanscripts Associated with CAD, TRACs, we employed innovative techniques to obtain high quality RNA from the samples and analyzed the RNA using current advanced next-generation sequencing (NGS) of RNA (RNAseq, or deep sequencing). From whole blood, we isolated RNA that was then depleted of ribosomal RNA. This RNA product was sequenced on a Helicos Single Molecule Sequencer. The resulting short reads were aligned to the human transcriptome and the number of reads per kilobase of exon per million (RPKM) reads was determined. We performed interim analysis on ten patients without CAD and 10 age/gender matched patients with CAD.
Results: We identified over 100 transcripts that differed more than 2-fold in expression between the two groups, p<.01. Many of these transcripts have not been previously associated with CAD, including phospholipase D2 (PLD2). Other transcripts such as estrogen receptor-beta (ESR2) have been previously associated with CAD using genome-wide SNP analysis. Uniquely, serine hydroxymethyltransferase 2 (SHMT-2) showed a 4-fold divergent expression of its two isoforms in the same CAD cohort.
Conclusions: We have established the ‘proof of principle’ that genome-wide transcript profiling of whole blood can be accomplished, and that the RNA transcripts have diagnostic value. Our data also demonstrates the unique depth of RNA analysis, detecting changes in splicing during disease states such as atherosclerosis. If these findings are validated with a larger patient cohort, this approach would provide a clinic-ready test to enhance the diagnosis of CAD. This non-invasive test could then be used as a tool to screen for CAD in both patients presenting with chest pain and asymptomatic patients with risk factors for cardiovascular disease with the potential goal of using this information to identify and tailor therapy for patients at risk for future coronary events.
- © 2012 by American Heart Association, Inc.