Early Stroke Volume Variation After Transcatheter or Surgical Aortic Valve Replacement Predicts Clinical Outcomes in Low-Flow Aortic Stenosis.

Background: Little is known about stroke volume index (SVi) change and its prognostic implication in patients with low-flow aortic stenosis (AS) undergoing aortic valve replacement (AVR) and conflicting results are present in literature. The aim of this study was to evaluate the postoperative change in SVi and its impact on outcomes in patients with low-flow severe AS undergoing AVR.

Methods: Retrospective observational study of a high-volume tertiary care center including consecutive patients with low-flow (SVi ≤ 35 mL/m) severe AS who underwent AVR (either surgical or transcatheter) with available comprehensive pre- and post-AVR echocardiographic assessment. Post-AVR SVi improvement was defined as an increase ≥ 15% from baseline, while SVi normalization was defined as post-AVR SVi > 35 mL/m. A up to 36-month follow-up was conducted and the study primary endpoint was the composite of all cause-mortality and hospitalizations for heart failure.

Results: One-hundred-fifty-one patients (mean age 80 ± 8 years, 53.6% female) were included. After AVR, SVi improved by > 15% in 51 (33.8%) and normalized in 51 (33.8%) patients. At a median follow-up of 17 (7-32) months, 62 (52.6%) patients reached the primary composite endpoint. SVi improvement, but not SVi normalization, was associated with better survival free from the primary endpoint (log rank p = 0.02 and 0.056, respectively). Multivariate analysis confirmed that both SVi improvement and its absolute change per mL/m unit carried a better prognosis (adj. HR 0.51 [0.28-0.91, p = 0.02] and 0.97 (0.94-0.99), p = 0.016, respectively).

Conclusions: In patients with low-flow AS undergoing AVR, early post-procedural SVi increase has beneficial prognostic significance. These findings highlight the importance of post-AVR hemodynamic assessment and may help refine risk stratification in this vulnerable population.