Role of homocysteine in atrial remodelling in atrial fibrillation

Abstract

High homocysteine levels seen in atrial fibrillation (AF) could be partly due to background coronary artery disease (CAD). We aimed to compare homocysteine concentrations between patients with or without AF carefully matched for history of CAD. We also aimed to determine association of homocysteine levels with atrial remodelling and risk of AF recurrence in study population with predominantly cardiac ischemic background. Homocysteine levels in 70 patients with paroxysmal or persistent AF with history of CAD and/or arterial hypertension who had undergone successful cardioversion were compared to 18 age, gender and co-morbidity matched patients with no history of AF. Left atrial size was measured by echocardiography and AF recurrence was recorded within 12-month follow up. Plasma homocysteine levels were significantly higher in AF patients than controls (9.9 ± 3.7 vs. 7.3 ± 2.0 μmol, respectively, p = 0.005). On univariate linear regression homocysteine levels were not related to echocardiographic parameters. However, after adjustment for age, gender, body mass index and history of CAD higher homocysteine levels were associated with increased left atrial diameter. During 1-year follow AF recurrence occurred in 42 (60%) of patients. On univariate logistic regression homocysteine was not related to AF recurrence, but the association became significant after adjustment for age, gender, body mass index and history of coronary artery disease. In conclusion, homocysteine levels are increased in AF patients with predominantly ischemic background and they are independently related to left atrial dilatation. In this patient population moderately-to-severely homocysteine increases rather than very severe homocysteine elevation is independently associated with increased risk of AF recurrences.

Keywords: Atrial fibrillation, atrial remodelling, homocysteine, left atrium, recurrence.