Abstract 13614: Atrial Fibrillation Increases Adverse Cardiac Events in Hypertrophic Cardiomyopathy With Moderate Tissue Fibrosis
Background: Atrial fibrillation (AF) is the common atrial arrhythmia, however, it is still unclear whether or not AF is a major risk for more advanced cardiac events in hypertrophic cardiomyopathy (HCM) patients. In this study, we sought to evaluate development of AF associated with tissue fibrosis and their prognostic value for advanced cardiac events in patients with HCM.
Methods: Of 494 HCM patients, 185 clinically diagnosed adn histopathologically confirmed patients were enrolled. The amount of fibrosis (%-area) was quantified using a digital microscope. Hemodynamic, echocardiographic, and electrophysiologic parameters were also evaluated.
Results: Fifty-seven (30%) patients had a history of AF, and during 5±4 years follow-up, 17 (9%) had a new onset of AF, thus total 74 (40%) patients had AF, which was associated with tissue fibrosis (OR 1.05; p=0.03), male sex (OR 2.1; p=0.1) and BNP level (OR 1.06/100pg/ml; p=0.1). On the other hand, 86 (46%) had adverse cardiac events (all-cause death, lethal arrhythmic events including ICD discharge, and hospitalization for heart failure) during follow-up, and patients with AF had higher incidence of the adverse cardiac events (p=0.01). Univariate analysis revealed that AF documentation (HR 1.72; p=0.01), tissue fibrosis (HR 1.04/%; p<0.0001), and PCWP (HR 1.05/mmHg; p<0.005) can predict the cardiac events. When grading the tissue fibrosis into three degrees, AF increased cardiac events in the moderate (10-20%/area) fibrosis (HR 2.24; p<0.01) (figure A), while AF did not alter the risk of cardiac events in the mild (<10%) or severe (>20%) fibrosis (Figure B).
Conclusion: Increased fibrosis was associated with AF occurrence, which worsened the prognosis in HCM patients with moderate fibrosis but not mild or severe fibrosis. Thus, therapeutic intervention for AF with HCM may lead to improve the cardiac mortality especially in patients with moderate fibrosis.
- © 2013 by American Heart Association, Inc.