Relationship Between Left Ventricular Ejection Fraction and Mortality in Asymptomatic and Minimally Symptomatic Patients With Severe Aortic Stenosis

Abstract

Objectives: This study sought to determine the best left ventricular ejection fraction (LVEF) cutoff value to predict long-term mortality in patients with asymptomatic or minimally symptomatic severe aortic stenosis (AS) and LVEF ≥50% under conservative management and after surgical correction of AS.

Background: Aortic valve replacement (AVR) is a Class I indication in asymptomatic patients with severe AS and LVEF <50%. However, this is an uncommon situation in asymptomatic severe AS (<1% of patients), usually occurring late in the course of the disease. No data are available concerning the prognostic value of LVEF in asymptomatic or minimally symptomatic AS patients with preserved LVEF (≥50%) in order to identify a LVEF threshold value associated with increased mortality.

Methods: This analysis included 1,678 patients with preserved LVEF and no or minimal symptoms, with a diagnosis of severe AS. The population was divided into 3 groups: LVEF <55%, LVEF 55% to 59%, and LVEF ≥60%.

Results: Five-year survival rate was 72 ± 2% for patients with LVEF ≥60%, 74 ± 2% for patients with LVEF between 55% and 59%, and 59 ± 4% for patients with LVEF <55% (p < 0.001). Under initially conservative or initially surgical management (surgery within 3 months after baseline echocardiography), patients with LVEF <55% displayed significant excess mortality compared to patients with LVEF≥ 60% (adjusted hazard ratio [HR]: 2.44 [95% confidence interval: 1.51 to 3.94]; p < 0.001 and 2.51 [95% confidence interval: 1.58 to 4.00]; p < 0.001, respectively), whereas patients with LVEF between 55% and 59% had comparable prognosis to those with LVEF ≥60% (p = 0.53 and p = 0.36, respectively). In patients with LVEF <55%, initial conservative management was associated with increased mortality compared to initial surgical management, even after covariate adjustment (adjusted hazard ratio [HR]: 2.70 [95% confidence interval: 1.98 to 3.67]; p < 0.001).

Conclusions: In patients with severe AS, preserved LVEF and no or minimal symptoms at the time of diagnosis, LVEF <55% is a marker of poor outcome, with medical or surgical management suggesting that these patients should be considered for surgery before this stage.

Keywords: aortic stenosis; conservative management; left ventricular ejection fraction; mortality; prognosis; surgery.