BACKGROUND: Emerging evidence suggests that the ratio between cardiac troponin (cTn) I and T may provide information on the risk of adverse outcomes in individuals with cardiovascular disease. Whether the cTn I/T ratio provides prognostic insights in the general population is unknown. METHODS: The cTn I/T ratio was calculated in 8855 participants (43% female, median age 56 years) from the Generation Scotland Study where both cTnI and cTnT concentrations were above the limit of blank. Multivariable cause-specific Cox proportional hazard models were used to estimate the associations between cTn I/T ratio and the primary outcome of cardiovascular or non-cardiovascular death. RESULTS: The median cTn I/T ratio was 0.5 (25th-75th percentile, 0.3-0.8) and median follow-up was 11.4 (10.8-12.7) years. Individuals in the highest ratio tertile (≥0.64) were more likely to be male, have a higher body mass index and systolic blood pressure, and a history of cardiovascular disease. Those in the lowest ratio tertile (<
0.38) were more likely to be smokers or have diabetes. After adjustment for cardiovascular risk factors, the cTn I/T ratio was positively associated with cardiovascular death (per doubling increase, adjusted hazard ratio [HR] 1.16 [95% CI, 1.05-1.28]), while an inverse association was observed for non-cardiovascular death (HR 0.89 [95% CI, 0.81-0.99]). CONCLUSIONS: The cTn I/T ratio is positively associated with cardiovascular death in the general population, while inversely associated with non-cardiovascular death. Future research is needed to unravel underlying mechanisms and determine whether the cTn I/T ratio provides valuable information regarding risk of cardiovascular and non-cardiovascular mortality to guide further management.