A. Collection of research measures (i) Blood resource Venous blood sampling and processing of samples Non-fasting blood samples were obtained from consenting participants, including those in whom a diagnosis of angina was subsequently ruled out, by staff trained in venepuncture during the hospital appointment. Twenty millilitres of blood was drawn to enable a wide range of research measures to be obtained. Blood was drawn into five vacutainers in the following order: 2x 4.0 mL ethylenediaminetetraacetic acid tube (EDTA), 1x 4.5 mL gel-separator lithium heparin tube (plasma separation tube (PST)), 1x 5.0 mL gel serum separator tube (SST), 2x 4.0 mL, and 1x 2.5 mL PAXgene ribonucleic acid (RNA) blood tube (PreAnalytiX, Franklin Lakes, NJ). Vacutainers were gently inverted and reverted up to five times to allow additives to mix with the blood, labelled and temporarily stored at approximately 5°C until processing. Date and time of collection was recorded. Different blood fractions were separated by centrifugation at 2500 g for 10 minutes. EDTA and PST samples were centrifuged within four hours after sampling and the SST sample was left to clot at room temperature for 25-30 minutes prior to centrifugation.