Cardiac troponin I/T ratio and cardiovascular mortality risk in hypertensive adults without heart failure: a prospective NHANES cohort study

Background Measurement of High-sensitivity cardiac troponin T (hs-cTnT) and high-sensitivity cardiac troponin I (hs-cTnI) as independent assays remain cornerstone of cardiology practice and are increasingly being recommended for early risk identification. Nevertheless, it remains unknown whether hs-cTn I/T ratio provides incremental prognostic value in hypertensive patients in the absence of heart failure (HF). Aim This study aimed to investigate the prognostic association of hs-cTn I/T ratio and risk of cardiovascular and non-cardiovascular outcomes in patients with hypertension Methods Data were obtained from the 1999–2004 National Health and Nutrition Examination Survey (NHANES) and linked to mortality records. Follow-up data was last updated until December 31, 2019. In adults aged ≥20 years with hypertension and no prior history of HF or established CVD (stroke, angina, myocardial infarction, coronary artery disease), we assessed the association between the cTnI/T ratio and risk of mortality outcomes using Cox proportional hazards model. The troponin I/T ratio was log₂-transformed prior to analysis. Results We analysed data on 31,126 participants, representing an estimated (weighted: 281.2M) non-institutionalized U.S. civilians. Of these, 4,234 met our inclusion criteria, majority 53.5% were females, mean age was 61 (46-72) years. Troponin ratios and associated demographics are summarised in Table 1 Results in Table 2 show that each log₂-unit increase in hs-cTn I/T ratio was associated with higher cardiovascular mortality after age and sex adjustment (HR 1.17, 95% CI 1.04–1.32; p=0.03). This remained significant after full multivariable adjustment (HR 1.19, 95% CI 1.06–1.34; p=0.005). No statistically significant associations were identified for all-cause mortality (HR 1.04, 95% CI 0.98–1.12; p=0.22), non-cardiovascular mortality (HR 0.99, 95% CI 0.90–1.08; p=0.74) or stroke (HR 1.21, 95% CI 0.96–1.54, p=0.11). Participants in the highest hs-cTn I/T ratio tertile had a greater risk of CV mortality relative to the lowest tertile (HR 1.36, 95% CI 1.04–1.72; p=0.03). In sensitivity analyses for CV mortality, the association of hs-cTn I/T ratio remained significant in males (HR 1.39, 95% CI 1.13–1.70; p=0.002). Use of the inverse hs-cTn T/I ratio yielded a reciprocal association (HR 0.84, 95% CI 0.75–0.95). Conclusion Cardiac Troponin I/T ratio was associated with increased CV mortality, while showing no significant association with non-cardiovascular, stroke, and all-cause mortality. These findings suggest that cTn I/T ratio may serve as a specific marker of CV risk stratification, but further studies are warranted to confirm its utility.