High-Sensitivity Troponin I in Atrial Fibrillation: Impact of rate and rhythm control and associations with biomarkers related to atrial fibrillation pathophysiology

Abstract

Cardiac troponins are intracellular proteins existing solely in cardiac myocytes. Highly sensitive troponin assays have revealed low levels of circulating troponins in individuals with atrial fibrillation that have been associated with increased risk of stroke and death. However, it is not clear whether the levels of troponins observed in atrial fibrillation are independent of underlying cardiovascular disease. The potential impact of different treatment modalities on troponin levels in atrial fibrillation is largely unknown. In this project we have used a highly sensitive assay for quantifying levels of Troponin I in three atrial fibrillation research projects conducted at Bærum Hospital. One of our findings was that atrial fibrillation was not independently associated with levels of Troponin I. We showed that Troponin I levels were unchanged six months after restoration of sinus rhythm by electrical cardioversion. Intriguingly, we found that Troponin I levels were lowered by rate-reducing drugs. This thesis has provided new information on the role of Troponin I in atrial fibrillation, which has clinical relevance as well as implications for future research.