Introduction:
Clinical cardiovascular disease is a major risk factor for cognitive impairment and dementia, but less is known about the association of subclinical myocardial damage (measured by highly sensitive cardiac troponin T [hs-cTnT]) with cognition and dementia in the general population.
Hypothesis:
We hypothesized that higher levels of hs-cTnT would be associated with lower cognitive test scores and increased risk of dementia.
Methods:
We conducted cross-sectional (1996-1998) and prospective (follow-up through 2009) analyses of 8,601 participants in the ARIC Study without a history of cardiovascular disease or stroke. Cognition was measured by 3 tests: Delayed Word Recall (DWR), Digit Symbol Substitution (DSS), and Word Fluency (WF). Dementia was defined using ICD-9 codes. Linear regression and Cox proportional hazards models were adjusted for demographic, lifestyle, and cardiovascular factors.
Results:
66% of participants had detectable hs-cTnT (≥0.003 μg/L) (mean age 63; 59% female; 20% black). In cross-sectional analyses, higher hs-cTnT was associated with lower scores on DSS (p-trend <0.001) and WF (p-trend=0.002), but not DWR (p-trend=0.09) (Table). Similarly, hs-cTnT ≥0.014 μg/L (≥99th percentile) vs. <0.014 μg/L was associated with lower scores on DSS (-1.78 points [95% CI: -2.61, -0.95]) and WF (-1.04 words [95% CI: -2.00, -0.07]), but not on DWR. Over a median of 12 years, there were 338 incident dementia cases. In prospective analyses, higher baseline levels of hs-cTnT were associated with increased dementia risk (p-trend <0.001) (Table).
Conclusion:
Higher levels of hs-cTnT were associated with lower cognitive test scores at baseline and increased dementia risk during follow-up. Our results suggest that subclinical myocardial damage is associated with cognition and dementia. This association may be driven by shared risk factors for myocardial and cerebral injury or as a direct result of subclinical small vessel or cardiac disease; more work is needed to elucidate potential mechanisms.
Lower cardiac troponin T levels in patients undergoing cardiopulmonary bypass and receiving high-dose aprotinin therapy indicate reduction of perioperative myocardial damage
