Table 5.

Consideration of the strengths and limitations of the IHD-EPITRAN study. ABI, ankle-brachial index, ATR, anatomical therapeutic chemical classification system; AVR, aortic valve replacement cohort III; AVS, aortic valve stenosis; CABG, coronary artery bypass grafting cohort II; CCTA, coronary computed tomography angiogram cohort IV; CVD, cardiovascular disease; DDT, defined daily dose, EV, extracellular vesicle; ICA, invasive coronary angiography; IHD, ischemic heart disease; PAD, peripheral artery disease; TTE, transthoracic echocardiography.

Strengths

1. Interdisciplinary collaboration enables simultaneous recruitment, sample handling and measurements.

2. A relevant IHD vs. non-IHD comparison is incorporated with a follow-up dimension as well.

3. Coronary artery status is visualized from all participants recruited.

4. Cardiac function is assessed by TTE from all participants recruited.

5. Exclusion of patients with prior clinically relevant manifestations of atherosclerosis than IHD.

6. Participants are surveyed for vascular claudication. ABI for the cohort II to record any asymptomatic PAD.

7. Cohort morbidity an dother background characteristics are meticulously registered, assessed and reported.

8. Study sample collection is designed to minimize the timespan for RNA vulnerable for degradation.

9. Sample use is optimized for as comprehensive measurements as possible. RNA is fractionated for analyses.

Limitations and management consideration

1. Coronary evaluation is non-uniform across cohorts.   SYNTAX with ICA for complexity assesment of IHD. The CCTA cohort IV is a primary non-IHD control.

2. Complete rule out of the effects of systemic atherosclerosis cannot be achieved   Most earlier manifestations of systemic atherosclerosis lead to exclusion, vascular claudication is surveyed (exclusion criterion) and ABI is measure from CABG cohort to record any asymptomatic PAD.

3. Limited possiblity to adjust medication effects (cohort IV has neither any CVD pathology nor medication).   ATC and DDT alterations are recorded and reported. Immunomodulatry, edication leads to exclusion.

4. Limited ability to pinpoint precise origins of the forthecoming epitranscriptomic alterations.   Buffy coat leukpcytes can be used for validation, plasma cfRNA is principally derived from EVs.

5. Incapability to identify biomarkers directly for subclinical IHD due to required cohort morbidity.   (1) Current study assesses the harnessing potential of epitranscriptomics for a source of IHD biomarkers   (2) Long-term follow-up of cohort IV can address the task.