Abstract
(1) Background: Although all severe calcific aortic stenosis (SCAS) patients have decreased sympathetic compensation to active standing, it has not been studied in patients who underwent aortic valve replacement (AVR). The objective was to assess the association of the heart rate variability (HRV) response to an active orthostatic challenge before AVR with the risk of complications or death during the AVR postoperative period in patients with SCAS. (2) Methods: This observational study included 49 patients. The cardiac autonomic activity was assessed by HRV analysis during supine position and active standing (five minutes each). (3) Results: Twenty-four patients (48.9%) who presented outcomes (complication or death) had a greater left ventricular (LV) mass and a smaller magnitude of change during active standing in both the mean cardiac period and sympathetic predominance. Poor sympathetic compensation to active standing and LV mass were independently associated with the outcome odds ratio (OR) = 4.8 [(1.06, 21.8), p < 0.041] and 1.03 [(1.007, 1.062), p < 0.013], respectively. (4) Conclusions: In SCAS patients, poor sympathetic compensation in the face of orthostatic challenge and greater LV mass are associated with complications or death after AVR surgery. This approach offers an opportunity to find new criteria to reduce the surgical risk of these patients.