Invasive hemodynamic assessments during transcatheter aortic valve implantation: comparison of patient outcomes in higher vs. lower transvalvular gradients with respect to left ventricular ejection fraction

Background: Low-flow and low-gradient (LFLG) aortic stenosis (AS), which can occur with reduced or preserved left ventricular ejection fraction (LVEF), represents a challenging patient subset. Since outcomes in patients with LFLG AS are worse following surgical aortic valve replacement, we analyzed outcomes in patients after transcatheter aortic valve implantation (TAVI) in our large database.

Methods and results: Among 841 treated patients, a total of 676 patients with complete dataset of invasive right- and left-sided hemodynamics were analyzed. Patients were subdivided into normal flow, high-gradient AS (NFHG: dPmean >40 mmHg, LVEF > 50%), paradoxical LFLG AS (PLFLG: dPmean ≤ 40 mmHg, LVEF > 50%, stroke volume index ≤ 35 ml/m(2)), and classical LFLG AS (CLFLG: dPmean ≤ 40 mmHg, LVEF ≤ 30%). Finally, global hemodynamics and patient outcomes and were compared. Patients with CLFLG AS had a higher prevalence of comorbidities and much higher logistic euro SCORE (35.8 ± 21.7) compared to PLFLG AS (20.0 ± 13.1) and NFHG AS (17.0 ± 11.9). Despite high procedural success rates in all groups, patients with CLFLG AS demonstrated a much higher 30-day and 1-year mortality (NFHG/PLFLG/CLFLG 30-day: 5.9/9.6/18.3 %; 1-year: 11.4/22.4/38.2%). Nevertheless, nearly all survivors demonstrated an improvement of functional capacity (NYHA class) and a decrease of NTproBNP levels during the follow-up.

Conclusion: The higher mortality in patients with CLFLG AS reflects an advanced disease state, possibly indicating a futile condition before TAVI. Nevertheless, high procedural success rates and a functional improvement in nearly all survivors support the concept of TAVI.