Severe autonomic failure as a predictor of mortality in aortic valve stenosis

Abstract

Background: Identification of new risk markers in aortic valve stenosis (AS) is of great interest. Here, we hypothesized that the presence of severe autonomic failure (SAF) is an important prognostic marker in both, symptomatic patients undergoing invasive treatment for severe AS, and in asymptomatic patients with severe AS who were primarily treated conservatively.

Methods: We prospectively enrolled 300 patients with severe AS (aortic valve area<1.0 cm2 or mean aortic gradient>40 mmHg) in sinus rhythm. All patients underwent a 24-h Holter recording for assessment of heart rate turbulence (HRT) and deceleration capacity (DC). Patients with both, abnormal DC and HRT were considered to suffer from SAF.

Results: The first hypothesis was tested in 216 symptomatic patients who underwent successful aortic valve replacement (AVR) or transcatheter aortic valve implantation (TAVI). During follow-up of 2 years, 29 of these patients died. SAF was the strongest independent predictor of mortality (hazard ratio 5.6, 95% confidence interval 2.6-12.0; p<0.001) with 2-year mortality rates of 50.0% and 10.7% in SAF-positive and SAF-negative patients, respectively (p<0.001). The second hypothesis was tested in 71 patients, who were asymptomatic at study entry and for whom a primarily conservative treatment strategy was proposed. During follow-up, 10 of these patients died. SAF also predicted death in asymptomatic patients with 2-year mortality rates of 52.4% and 8.7% in SAF-positive and SAF-negative patients, respectively (p=0.010).

Conclusions: SAF is a strong and independent predictor of mortality in symptomatic and asymptomatic patients with severe AS.

Keywords: Aortic valve stenosis; Cardiac autonomic function; Deceleration capacity; Heart rate turbulence; Risk prediction.