Surgeon Frequency of Aortic Root Enlargement and Long-Term Survival in Medicare Beneficiaries Undergoing Surgical Aortic Valve Replacement.

Abstract

Aortic root enlargement (ARE) is a variably performed during surgical aortic valve replacement (SAVR) to minimize patient-prothesis mismatch (PPM), but its impact on survival remains under-evaluated. We retrospectively analyzed Medicare beneficiaries (1999-2019) undergoing isolated SAVR with or without non-Konno ARE. Procedural details were doubly-adjudicated by ICD and CPT codes. Overlap propensity score weighting adjusted for confounders. Restricted mean survival times (RMST) at 30-days and 20-years were compared. Surgeons were stratified by ARE frequency, and survival was analyzed using risk-adjusted Kaplan-Meier estimates in both "as-treated" (SAVR vs SAVR+ARE) and "surgeon-preference" (never-ARE vs frequent-ARE surgeons) analyses. Of 214,266 beneficiaries undergoing isolated SAVR, 6,652 (3.1%) underwent SAVR+ARE. From 1999 to 2019, ARE utilization increased from 2.1% to 6.4% (Cochran-Armitage Z-statistic: 15.2). Among 3,018 surgeons, 1,513 never performed ARE (69,389 beneficiaries), 1,227 performed ARE in <10% of cases (128,258 beneficiaries), and 278 performed ARE in ≥10% of cases (16,619 beneficiaries). After risk-adjustment, survival was significantly lower in SAVR+ARE compared to SAVR recipients: 30-day RMST 28.73(28.60,28.87) versus 29.35(29.26,29.45) days (p = 0.013) and 20-year RMST 9.15(8.96,9.35) vs 9.49(9.30,9.69) years (p = 0.018). Similarly, beneficiaries treated by frequent-ARE surgeons experienced worse early risk-adjusted survival without any late survival benefit: 30-day RMST 29.19(29.11,29.27) versus 29.33(29.25-29.40) days (p = 0.013), 20-year RMST 9.04(8.90,9.18) versus 9.13(9.00,9.27) (p = 0.351). Landmark analysis of 1-year survivors showed no late survival difference (p = 0.456 "as-treated" analysis; p = 0.943 "surgeon-preference" analysis). Even among frequent-ARE surgeons, SAVR+ARE was associated with higher 30-day and reduced 20-year RMST relative to SAVR alone. In conclusion, ARE was associated with higher early mortality and no long-term survival advantage compared to SAVR alone (even among frequent-ARE surgeons), as was undergoing surgery by a frequent ARE surgeon. Further studies are required to assess the potential utility of ARE in younger patients, those with small annuli, and those at risk for PPM.