Cornwell, MacIntosh

Introduction: Circulating biomarkers may improve prediction of cardiovascular (CV) events in chronic coronary disease (CCD). The incremental value of biomarkers in CCD after adjustment for clinical factors, inducible ischemia and coronary artery disease (CAD) severity is uncertain. Methods: 756 ISCHEMIA (International Study of Comparative Health Effectiveness with Medical and Invasive Approaches) participants with site-determined moderate-severe ischemia and 9 assayed biomarkers (Figure) were included. Among participants with interpretable stress tests for ischemia and CAD by computed coronary tomography angiography (CCTA) (N=507), associations of biomarkers with the primary (CV death, myocardial infarction (MI), or hospitalization for unstable angina, heart failure, or resuscitated cardiac arrest) or secondary endpoints (CV death or MI) were evaluated using sequentially adjusted multivariable Cox proportional hazards models (Model 1=unadjusted, Model 2=clinical features, Model 3=Model 2 + multivessel CAD by CCTA, and Model 4=Model 3 + severe ischemia). Results: Median (IQR) participant age was 64 (57-70) years, 19% were female, 81% white, and 5% Hispanic. Hypertension (85%), diabetes (46%) and obesity (45%) were common, 28% had an estimated glomerular filtration rate <60 ml/min/1.73m 2 . Severe ischemia was present in 44%, and 39% had multivessel CAD (≥70% stenosis) by CCTA. Over 3.5 (2.4-4.7) years of follow-up there were 146 (19%) primary and 128 (17%) secondary endpoints. Soluble CD40L, GDF-15, NT-proBNP, hsTnT were associated with the primary and secondary endpoints in univariable and multivariable (adjusting for clinical features, multivessel CAD and severe ischemia) models. Conclusion: Biomarkers of inflammation (GDF-15), thrombosis (sCD40L), myocardial stretch (NT-proBNP) and injury (hs-troponin) were associated with CV endpoints in the ISCHEMIA trial independent of clinical features, multivessel CAD and severe ischemia.

Introduction: Chronic coronary disease (CCD) is a leading cause of death worldwide. Whole blood (WB) transcriptomic (RNA-seq) and methylation ‘omics’ data can discern molecular underpinnings of CCD and create molecular subtypes to aid risk prediction. Methods: Of 1,064 participants with moderate-severe ischemia (Age: 67.1±6.2, 19.4% Female, 17% non-White) from the ISCHEMIA (International Study of Comparative Health Effectiveness with Medical and Invasive Approaches) biorepository, 646 participants had available WB RNA-seq and 737 had WB methylation data ( Fig 1A ). Unsupervised clustering and differential analyses identified omics-derived molecular subtypes. We identified co-regulated gene modules of each subtype, performed subtype-level enrichment of clinical variables, and performed Kaplan-Meier analyses for time to cardiovascular (CV) death or myocardial infarction (MI). Results: Multi-omic analysis revealed 4 RNA-seq-derived subtypes (RS) and 3 methylation-derived subtypes (MS). RNA-seq Subtype 1 (RS1) was enriched for molecular drivers indicative of an adaptive immune response, had clinical enrichment of female sex, statin use, and greater ischemia, and had decreased risk of CV death or MI ( Fig 1B ). RNA-seq Subtype 2 (RS2) was enriched for innate immune response pathway, and patients who were older and White, and was associated with increased risk of CV death or MI. Similarly, methylation subtypes also yielded a high-risk subtype (MS3) and a low-risk subtype (MS2) ( Fig 1C ). Integration of transcriptomic and methylomic subtypes led to further distinction of resilient and vulnerable subgroups. Conclusions: WB RNA-seq and methylation data identified molecularly-defined subtypes that informed the underlying disease pathology of CCD patients in ISCHEMIA. These subgroups were differentially enriched for clinical characteristics and event outcomes, demonstrating the potential use for blood-based omics tests to aid in the prognosis of CCD.