Incremental Prognostic Value of Left Ventricular Global Longitudinal Strain in Patients with Preserved Ejection Fraction Undergoing Transcatheter Aortic Valve Implantation

Abstract

Background: Evaluation of left ventricular global longitudinal strain (LVGLS) has allowed better characterization than left ventricular ejection fraction (LVEF) of subtle differences in left ventricular performance. The aim of this study was to determine whether LVGLS has prognostic value in patients with severe aortic stenosis and preserved LVEF undergoing transcatheter aortic valve implantation (TAVI).

Methods: Among 412 consecutive patients who underwent TAVI, 344 patients (mean age, 78.9 ± 5.0 years; 161 men) with preserved LVEF (≥50%) at baseline were analyzed. Patients with low LVEF (<50%) were used as a comparison group in the survival analysis. The primary and secondary end points were all-cause death and a composite of cardiovascular death and heart failure hospitalization, respectively.

Results: The mean LVGLS and LVEF were -17.1 ± 2.7% and 63 ± 5%, respectively. Impaired LVGLS was defined as >-16%, which was the first LVGLS quartile (cutoff value, -16%). The estimated actuarial 5-year survival rate was 81.7 ± 4.2% in the normal LVGLS group and 66.8 ± 7.5% in the impaired LVGLS group (P = .005). In the multivariable analysis, impaired LVGLS was an independent predictor of all-cause death (adjusted hazard ratio, 2.26; 95% CI, 1.11-4.60) and the composite outcome (adjusted hazard ratio, 3.03; 95% CI, 1.45-6.33). Moreover, the impaired LVGLS group had a poor prognosis, similar to the impaired LVEF group (<50%). The addition of the absolute value of LVGLS to the clinical parameters and LVEF led to significant improvement in the prediction of all-cause mortality.

Conclusions: In patients with severe aortic stenosis and preserved LVEF undergoing TAVI, subclinical LV dysfunction defined by impaired LVGLS is independently associated with poor clinical outcomes. LVGLS measurement provides incremental prognostic value above the established clinical and echocardiographic parameters.