Transcatheter Aortic Valve Implantation Outcomes in Patients with Low Flow Low Gradient Aortic Stenosis

Background: Some studies suggest that patients with low flow low gradient (LF-LG) aortic stenosis (AS) may achieve worse results after undergoing transcatheter aortic valve implantation (TAVI). Purpose: To compare outcomes between LF-LG AS and high gradient (HG) AS patients submitted to TAVI. Methods: Inclusion of 480 consecutive patients who underwent TAVI between 2008 and 2020 at a single tertiary center. Patients were divided into high gradient AS and LF-LG AS; and baseline characteristics and outcomes after the procedure were collected and compared between groups. Results: Patients with LF-LG AS had worse baseline characteristics, with higher Society of Thoracic Surgeons score (p=0.008), New Euroscore II (p<0.0001), and NT pro-natriuretic peptide B (p=0.001), more frequent left ventricular ejection fraction (LVEF) <40% (p<0.0001), coronary artery disease (p<0.0001), including previous myocardial infarction (p=0.002) and coronary artery bypass graft (p<0.0001), poor vascular accesses (p=0.026) and periprocedural angioplasty (p=0.038). In a multivariate analysis, adjusted to differences in baseline characteristics, LF-LG AS was associated with worse functional class at one year (p=0.023) and in the long-term (p=0.004) and with heart failure hospitalizations at one year and in the long-term (p=0.001 and p<0.0001). In a sub-analysis including only patients with LF-LG AS, those with LVEF <40% had the worst outcomes, with more global (p=0.035) and cardiovascular (p=0.038) mortality. Conclusion: Patients with LF-LG AS have worse short and long-term outcomes, even when adjusted for baseline characteristic differences. The sub-group of patients with LVEF <40% have the most ominous global outcomes.