Prognostic significance of atrial fibrillation and severity of symptoms of heart failure in patients with low gradient aortic stenosis and preserved left ventricular ejection fraction.

The aims of this study were to investigate the clinical outcomes of patients with low-gradient aortic stenosis despite preserved left ventricular ejection fraction and to assess reliable prognostic clinical-instrumental features in patients experiencing or not experiencing aortic valve replacement (AVR). Clinical-laboratory and echocardiographic data from 167 patients (median age 78 years, interquartile range 69 to 83) with aortic valve areas <1.0 cm(2), mean gradients ≤30 mm Hg, and preserved left ventricular ejection fraction (≥55%), enrolled from 2005 to 2010, were analyzed. During a mean follow-up period of 44 ± 23 months, 33% of patients died. On multivariate analysis, independent predictors of death were baseline New York Heart Association functional class III or IV (hazard ratio 2.16, p = 0.038) and atrial fibrillation (hazard ratio 2.00, p = 0.025). Conversely, AVR was protective (hazard ratio 0.25, p = 0.01). The magnitude of the protective effect of AVR seemed to be relatively more important in patients with atrial fibrillation than in those in sinus rhythm, independently of the severity of symptoms. Age >70 years showed a trend toward being a prognostic predictor (p = 0.082). In conclusion, in patients with low-gradient aortic stenosis despite a preserved left ventricular ejection fraction, AVR was strongly correlated with a better prognosis. Patients with atrial fibrillation associated with advanced New York Heart Association class had the worst prognosis if treated medically but at the same time a relative better benefit from surgical intervention.