Prognostic Impact of Computed Tomography-Derived Abdominal Fat Area on Transcatheter Aortic Valve Implantation

Background: Obesity has previously been identified as an indicator of good prognosis in patients undergoing transcatheter aortic valve implantation (TAVI), an association known as the "obesity paradox". We investigated whether abdominal total fat area (TFA), visceral fat area (VFA), or subcutaneous fat area (SFA) are prognostic indicators of long-term clinical outcome in patients undergoing TAVI. Methods and Results: We retrospectively analyzed 100 consecutive patients who underwent TAVI between December 2013 and April 2017. TFA, VFA, and SFA were measured from routine pre-procedural computed tomography (CT). Patients were divided into 2 groups according to median TFA, VFA, or SFA, and we investigated the association of abdominal fat area with adverse clinical events, including all-cause death and re-hospitalization due to worsening heart failure. At a median follow-up of 665 days, patients with higher SFA had significantly lower incidence of the composite outcome and all-cause death compared with patients with lower SFA (15.0% vs. 37.7%, P=0.025; and 8.9% vs. 23.7%, P=0.047, respectively). In contrast, patients with higher TFA or VFA did not show significant reduction in the incidences of the composite outcome or all-cause mortality. Conclusions: CT-derived SFA had prognostic value in patients undergoing TAVI.