Whole blood transcriptional profiling by RNA sequencing in patients with ST-elevation and non-ST elevation myocardial infarction

Aims. We sought for peripheral blood gene expression signatures at presentation that distinguish the ST elevation (STEMI) and non-ST elevation myocardial infarction (NSTEMI) conditions, to define a precise map of differentially regulated biological processes, unveil new distinctive traits, and help predict markers of outcome. Methods and results. Total RNA from whole blood of STEMI and NSTEMI patients was used to prepare poly(A)+ enriched libraries for paired-end RNA-Seq. Transcriptomes were reconstructed and, after adjustment for unwanted variation, we performed differential expression analysis. Enrichment analyses was performed to infer differentiating functional networks. We identified 153 differentially expressed genes, which stood correction for TnI levels at admission and included 32 putative novel genes (false discovery rate-adjusted P<0.05). We found a divergent modulation of inflammatory, immune-response, angiogenic, and mitochondrial dynamics pathways. Finally, we showed that specific gene expression patterns at admission predict troponin I (TnI) peak levels and/or GRACE risk score. Conclusions. RNA-Seq allowed identifying novel differentially expressed genes in STEMI vs. NSTEMI, which might uncover unappreciated mechanisms underlying acute MI. Overall, our results depicted a scenario characterizing different pathological traits of these two types of acute MI that could pave the way for the identification of novel, specific biomarkers for early diagnosis, risk stratification, and therapeutic decision-making. Whole blood poly(A)+ RNA profiles of 15 STEMI and 15 NSTEMI patients were generated through RNA-Seq using the SOLiD 5500xl system.