Introduction and Hypothesis: High troponin levels reflect myocardial damage in patients with heart disease and predict poor prognosis in stroke and cardiomyopathies. In the study, we test the hypothesis that high troponin levels in the setting of chronic renal insufficiency (CRI) significantly predict the risk of first time stroke.
Method: The Chronic Renal Insufficiency Cohort Study enrolled a total of 3,477 patients with no previous history of stroke at baseline were used in this study. High troponin level is defined as troponin levels ≥0.03 ug/L. Incident hemorrhagic and ischemic strokes were classified using ICD-9. The associations between baseline troponin levels and incidence of hemorrhagic and ischemic stroke and risk of all-cause mortality were analyzed prospectively using multivariate Cox’s regression analysis technique.
Results: With an average (SD) of 7.7 (1.5) years of follow-up, 23 participants developed incident hemorrhagic stroke (HS), and 84 developed incident ischemic stroke (IS). Participants with high troponin had significantly higher IS rate than those with low troponin (9.69% vs. 2.81%, p<.0001). After adjustment for age, race, smoking, body mass index, systolic blood pressure, eGFR, total cholesterol to HDL ratio, diabetes, and myocardial infarction, Cox’s models indicate that participants with high troponin had 2.68 times higher risk of incident IS than those with low troponin (HR: 2.68, 95%CI: 1.55-4.62, p=0.0004). Females with high troponin had a significantly higher risk of IS than males (excess HR=3.41, 95%CI 1.25-8.41, p=0.016). Participants with high troponin had a significantly increased risk of all-cause mortality in both sexes. Of them, females with high troponin had a significantly higher risk of all-cause mortality than males (HR=1.57, 95%CI: 1.15-2.16, p=0.005). No statistical significance was observed for the risk of incident HS.
Conclusion: In CRI patients elevated serum troponin levels were significantly associated with the risk of first time IS and higher all-cause mortality risk. The risk is further amplified significantly in females compared to males indicating sex differences play an important role in first time stroke risk in CRI. These findings represent an unexplored risk of IS.