Outcome of Transcatheter Aortic Valve Implantation in Patients With Low-Gradient Severe Aortic Stenosis and Preserved Left Ventricular Ejection Fraction

We aimed to evaluate the clinical and hemodynamic impact of transcatheter aortic valve implantation in patients with typical low-gradient severe aortic stenosis (LGSAS) and at high operative risk for surgical valve replacement. Prospectively collected clinical and echo Doppler data were retrospectively analyzed in 112 and 86 patients, respectively. Follow-up period was 31 months (21 to 38). Thirty-eight patients died; combined long-term cardiovascular events were identified in 68 patients. The 30-day mortality rate was 2.4% in patients with typical severe aortic stenosis (AS) and 3.3% in patients with LGSAS (p = 1.0). Two-year survival rate was 77 ± 5% for the former (n = 82) and 68 ± 8% for the latter (n = 30; hazard ratio 1.4, 95% confidence interval 0.7 to 2.7 for LGSAS; p = 0.3). Two-year cardiovascular event-free survival rates were 56.5 ± 5.0% and 48.4 ± 9.0%, respectively, (hazard ratio 1.4, 95% confidence interval 0.78 to 2.3 for LGSAS; p = 0.25). Patients with typical severe AS (n = 64) and those with LGSAS (n = 23) demonstrated similar increases in left ventricular ejection fraction and stroke volume (7 ± 10% vs 6 ± 6% and p = 0.67; 12 ± 22% vs 12 ± 16%, p = 0.88, respectively) and reduction in systolic pulmonary artery pressure (5 ± 14 vs 5 ± 9 mm Hg, respectively, p = 0.83). In conclusion, transcatheter aortic valve implantation appears to result in similar hemodynamic and long-term clinical outcomes for high-risk surgical patients with LGSAS as those with typical severe AS.