Abstract
Background: Observational studies have shown that elevated circulating cardiac troponin I (cTnI) concentrations were associated with higher risk of stroke and atrial fibrillation, but the causality remains unclear. Therefore, we conducted a two-sample mendelian randomization study to evaluate the causal effects of cTnI concentrations on the risk of stroke subtypes and atrial fibrillation.Methods: The instrumental variables for circulating cTnI concentrations were selected from a genome-wide association study meta-analysis of 48,115 European individuals. Applying a 2-sample mendelian randomization approach, we examined the associations of circulating cTnI concentrations with stroke (40,585 cases and 406,111 controls), ischemic stroke (34,217 cases and 406,111 controls), ischemic stroke subtypes (cardioembolic, large artery, small vessel stroke), intracerebral hemorrhage (1,545 cases and 1,481 controls) and atrial fibrillation (60,620 cases and 970,216 controls). Results: Genetically predicted elevated circulating cTnI concentrations were associated with increased risk of cardioembolic stroke (odds ratio [OR], 1.80; 95% confidence interval [CI], 1.20-2.68; P = 0.004). However, no significant association was observed for cTnI concentrations with large artery stroke, small vessel stroke, total stroke, ischemic stroke and intracerebral hemorrhage. Additionally, we also found that elevated cTnI concentrations were associated with higher risk of atrial fibrillation (OR, 1.30; 95% CI, 1.10-1.53; P = 0.003).Conclusions: This study provides evidence that genetically predicted circulating cTnI concentrations are causally associated with increased risk of cardioembolic stroke and atrial fibrillation.
Genetically Predicted Cardiac Troponin I Concentrations and Risk of Stroke and Atrial Fibrillation
