Imprecision of annular sizing in low-risk patients with aortic stenosis and its impact on transcatheter aortic valve size

Aortic stenosis (AS), the most prevalent heart valve disease, is treatable through Surgical Aortic Valve Replacement (SAVR) or Transcatheter Aortic Valve Implementation (TAVI). Precise valve sizing is crucial for optimal clinical outcomes, minimizing risks like paravalvular leakage, conduction abnormalities, and patient-prosthesis mismatch. SAVR valve sizing is intraoperative, while Multidetector Computed Tomography (MDCT) measurements serve as the gold standard for TAVI sizing. The recent expansion of TAVI to low-risk patients reflects heightened confidence in its safety and efficacy. However, little is known about annular sizing imprecision in low-risk TAVR patients and its impact on valve size. This study aims to evaluate the inter- and intra-observer variability of MDCT-based measurements (annular area, perimeter, and diameter) and their impact on TAVI valve sizing. A secondary objective involves assessing intraoperative annular measurements against MDCT measurements. Fifty low-surgical-risk patients underwent SAVR. Preoperative MDCT, evaluated by three experienced cardiac MDCT operators, measured aortic annular parameters. Inter- and intra-observer variability were compared with intraoperative aortic valve sizers and predefined TAVI valve sizes. Among fifty low-risk patients with AS, strong correlation (Pearson > 0.90) was observed for all MDCT measurements between operators. However, interindividual differences led to diverse TAVI valve sizing in 40% of patients. No specific operator emerged as an outlier. Intraoperative annular diameter consistently measured smaller than MDCT-derived measurements. MDCT aortic annular measurements in AS patients exhibit strong correlation between operators. Yet, inter-operator discrepancies significantly impact TAVI valve sizing in a high percentage of patients, emphasizing the need for improved standardization.