Defining normality in a European multinational cohort: Critical factors influencing the 99th percentile upper reference limit for high sensitivity cardiac troponin I

•A questionnaire and biomarkers were used to define a cardio-healthy cohort.•Male gender, BNP, HbA1c and smoking were associated with hs-cTnI concentration.•Introduction of selection criteria decreased the impact of age on hs-cTnI value.•Non-parametric analysis results were higher than from robust statistical analysis.•99th percentile URL ranged from 23.7 to 7.1ng/L depending on analysis.